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![Figure 2. The original life zone chart of Holdridge [4].](publication/264499178/figure/fig2/AS:295974661574658@1447577266415/The-original-life-zone-chart-of-Holdridge-4_Q320.jpg)
The Holdridge life zone system has already been used a number of times for analysing the effects of climate change on vegetation. But a criticism against the method was formulated that it cannot interpret the ecotones (e.g. forest steppe). Thus, in this paper transitional life zones were also determined in the model. Then, both the original and mod...
Contexts in source publication
Context 1
... is the potential evapotranspiration ratio [di- APE mensionless]; is the annual potential evapotranspi- APP ration [mm]; is the annual total precipitation [mm]; P(i) i the monthly total precipitation of the th month [mm]. The Holdridge life zone system is one of the best methods, which uses only temperature and precipitation data for description of the terrestrial ecosystem complexes. Each life zone type has exact definition based on the three cli- ABT, APP, PER mate indices ( ). Holdridge developed a geometric model which declares the relationship between life zones and climate indices. This geometric model - so- called the life zone chart ( Figure 2) - is a triangular coor- dinate system, in which the climate indices are depicted on logarithmic axes in recognition of Mitscherlich’s law of ABT ≈ ◦ ( 2 12+0 5) diminishing returns [6]. The of 17 C (2 ◦ ≈ ◦ C 16.97 C) was defined as a critical temperature line - so-called the frost line - which separates the warm temperate region from the subtropical region [3]. The frost line The life represents zone chart the consists dividing of line 37 between hexagons. two Each major hexagon phys- iological defines a groups life zone of which evolved is plants. named to On indicate the warmer a vegeta- side of tion the association. line, the majority Hexagons of the and plants triangles are sensitive were defined to low in temperatures [4]. ABT, APP PER the chart using guide lines of and which are denoted in Figure 2 by dashed lines. Hexagons determine core life zones; while the equilateral triangles can be termed as transitional life zones. Holdridge [4] considered also the determination of the transitional life zones, but taking into account of the large number of classes would be excessive. For this reason, each triangle was divided into three equal parts using straight lines which connect the centre of triangle to all three ver- tices. Then these smaller triangles were annexed to the adjacent hexagons which determine core life zones. As a result, larger hexagons, whose contours were denoted in Figure 2 by solid lines, appeared around the former hexagons (core life zones). These larger hexagons are the units of the original Holdridge life zone system, so-called life zones. The life zone system was developed for the tropical re- gions’ investigation [4]. The main purpose of that investigation was to better understand the relation between climate and vegetation in both mountains and lowlands. So Holdridge defined not only latitudinal regions but also ABT altitudinal belts based on the values of . He found it necessary to determine which the more important limit ABT factor of the (and thus the vegetative growth) is: a. elevation; b. distance from the Equator. On global scale the model is inapplicable for classification, when the altitudinal belts are used too, because of the number of classes would already be 117. For this reason, most studies [12, 13, 14, 15], which use Holdridge life zone model for climate classification, neglect the altitudinal belts. The life zone chart consists of 37 hexagons. Each hexagon defines a life zone which is named to indicate a vegetation association. Hexagons and triangles were defined in ABT, APP PER the chart using guide lines of and which are denoted in Figure 2 by dashed lines. Hexagons determine core life zones; while the equilateral triangles can be termed as transitional life zones. Holdridge [4] considered also the determination of the transitional life zones, but taking into account of the large number of classes would be excessive. For this reason, each triangle was divided into three equal parts using straight lines which connect the centre of triangle to all three ver- tices. Then these smaller triangles were annexed to the adjacent hexagons which determine core life zones. As a result, larger hexagons, whose contours were denoted in Figure 2 by solid lines, appeared around the former hexagons (core life zones). These larger hexagons are the units of the original Holdridge life zone system, so-called life zones. The life zone system was developed for the tropical re- gions’ investigation [4]. The main purpose of that investigation was to better understand the relation between climate and vegetation in both mountains and lowlands. So Holdridge defined not only latitudinal regions but also ABT altitudinal belts based on the values of . He found it necessary to determine which the more important limit ABT factor of the (and thus the vegetative growth) is: a. elevation; b. distance from the Equator. On global scale the model is inapplicable for classification, when the altitudinal belts are used too, because of the number of classes would already be 117. For this reason, most studies [12, 13, 14, 15], which use Holdridge life zone model for climate classification, neglect the altitudinal belts. The life zone system has been criticized that life zones don’t always coincide with observed vegetation (i.e. often the grasslands are classified as forests). One reason for this probably is that transitional life zones had not been determined by Holdridge [3, 4]. The model had been optimized for global scale. If transitional life zones were defined too, 89 life zone types (38 core life zones + 51 transitional life zones) would be determined. Namely, this large number of classes would make it impossible to visually represent the life zones. In this paper regional scale analysis was performed, so it has been considered appropriate to determine transi- tional life zones. These new units of model have been defined based on latitudinal regions (Table 2) and humidity provinces (Table 3). Transitional life zones were not distributed among life zones in contrary of the original model, but these were determined as separate units. These new classes were named according to the following steps: a. latitudinal belts and humidity provinces were determined; b. names of vegetation associations were defined as combination of two adjacent core life zones from the same latitudinal belts. The new classes’ list can be found in the legend of Figure 3. Each of transitional life zones was not defined which has got only one adjacent core life zone. Thus, only 43 transitional life zones were determined. Every transitional life zone which verges on one of the forest types (e.g. dry forest) and one of the steppe types (e.g. thorn steppe) were defined as forest steppe. The forest steppe is defined as a separate vegetation belt developed in the transitional climate between the zones of closed forests and steppe grasslands, in which more or less closed forests alternate with closed grasslands, forming a landscape of mosaic appearance [26]. One of the main reasons for the defining of transitional life zones was specifically to determine this ecotone and estimate changes in its spatial characteristics. Each life zone’s criteria are shown by Figure 3. For ex- ample, the criteria of "boreal dry scrub" core life zone are ◦ ABT ◦ APP the followings: a. 3 C < < 6 C; b. 125 mm < PER < 250 m; c. 1 < < 2. The climate/vegetation can be identified as "subpolar subhumid moist-wet tundra" transi- tional life zone, if the following three criteria are fulfilled ABT ◦ APP simultaneously: a. < 3 C; b. 250 mm < ; c. 0.5 PER < . For the validation of classification methods the Kappa statistic [16] was used. This method has been commonly applied for comparing two vegetation maps [7, 27, 28]. The κ Kappa statistic ( ) is determined according to the following ...
Context 2
... is the potential evapotranspiration ratio [di- APE mensionless]; is the annual potential evapotranspi- APP ration [mm]; is the annual total precipitation [mm]; P(i) i the monthly total precipitation of the th month [mm]. The Holdridge life zone system is one of the best methods, which uses only temperature and precipitation data for description of the terrestrial ecosystem complexes. Each life zone type has exact definition based on the three cli- ABT, APP, PER mate indices ( ). Holdridge developed a geometric model which declares the relationship between life zones and climate indices. This geometric model - so- called the life zone chart ( Figure 2) - is a triangular coor- dinate system, in which the climate indices are depicted on logarithmic axes in recognition of Mitscherlich’s law of ABT ≈ ◦ ( 2 12+0 5) diminishing returns [6]. The of 17 C (2 ◦ ≈ ◦ C 16.97 C) was defined as a critical temperature line - so-called the frost line - which separates the warm temperate region from the subtropical region [3]. The frost line The life represents zone chart the consists dividing of line 37 between hexagons. two Each major hexagon phys- iological defines a groups life zone of which evolved is plants. named to On indicate the warmer a vegeta- side of tion the association. line, the majority Hexagons of the and plants triangles are sensitive were defined to low in temperatures [4]. ABT, APP PER the chart using guide lines of and which are denoted in Figure 2 by dashed lines. Hexagons determine core life zones; while the equilateral triangles can be termed as transitional life zones. Holdridge [4] considered also the determination of the transitional life zones, but taking into account of the large number of classes would be excessive. For this reason, each triangle was divided into three equal parts using straight lines which connect the centre of triangle to all three ver- tices. Then these smaller triangles were annexed to the adjacent hexagons which determine core life zones. As a result, larger hexagons, whose contours were denoted in Figure 2 by solid lines, appeared around the former hexagons (core life zones). These larger hexagons are the units of the original Holdridge life zone system, so-called life zones. The life zone system was developed for the tropical re- gions’ investigation [4]. The main purpose of that investigation was to better understand the relation between climate and vegetation in both mountains and lowlands. So Holdridge defined not only latitudinal regions but also ABT altitudinal belts based on the values of . He found it necessary to determine which the more important limit ABT factor of the (and thus the vegetative growth) is: a. elevation; b. distance from the Equator. On global scale the model is inapplicable for classification, when the altitudinal belts are used too, because of the number of classes would already be 117. For this reason, most studies [12, 13, 14, 15], which use Holdridge life zone model for climate classification, neglect the altitudinal belts. The life zone chart consists of 37 hexagons. Each hexagon defines a life zone which is named to indicate a vegetation association. Hexagons and triangles were defined in ABT, APP PER the chart using guide lines of and which are denoted in Figure 2 by dashed lines. Hexagons determine core life zones; while the equilateral triangles can be termed as transitional life zones. Holdridge [4] considered also the determination of the transitional life zones, but taking into account of the large number of classes would be excessive. For this reason, each triangle was divided into three equal parts using straight lines which connect the centre of triangle to all three ver- tices. Then these smaller triangles were annexed to the adjacent hexagons which determine core life zones. As a result, larger hexagons, whose contours were denoted in Figure 2 by solid lines, appeared around the former hexagons (core life zones). These larger hexagons are the units of the original Holdridge life zone system, so-called life zones. The life zone system was developed for the tropical re- gions’ investigation [4]. The main purpose of that investigation was to better understand the relation between climate and vegetation in both mountains and lowlands. So Holdridge defined not only latitudinal regions but also ABT altitudinal belts based on the values of . He found it necessary to determine which the more important limit ABT factor of the (and thus the vegetative growth) is: a. elevation; b. distance from the Equator. On global scale the model is inapplicable for classification, when the altitudinal belts are used too, because of the number of classes would already be 117. For this reason, most studies [12, 13, 14, 15], which use Holdridge life zone model for climate classification, neglect the altitudinal belts. The life zone system has been criticized that life zones don’t always coincide with observed vegetation (i.e. often the grasslands are classified as forests). One reason for this probably is that transitional life zones had not been determined by Holdridge [3, 4]. The model had been optimized for global scale. If transitional life zones were defined too, 89 life zone types (38 core life zones + 51 transitional life zones) would be determined. Namely, this large number of classes would make it impossible to visually represent the life zones. In this paper regional scale analysis was performed, so it has been considered appropriate to determine transi- tional life zones. These new units of model have been defined based on latitudinal regions (Table 2) and humidity provinces (Table 3). Transitional life zones were not distributed among life zones in contrary of the original model, but these were determined as separate units. These new classes were named according to the following steps: a. latitudinal belts and humidity provinces were determined; b. names of vegetation associations were defined as combination of two adjacent core life zones from the same latitudinal belts. The new classes’ list can be found in the legend of Figure 3. Each of transitional life zones was not defined which has got only one adjacent core life zone. Thus, only 43 transitional life zones were determined. Every transitional life zone which verges on one of the forest types (e.g. dry forest) and one of the steppe types (e.g. thorn steppe) were defined as forest steppe. The forest steppe is defined as a separate vegetation belt developed in the transitional climate between the zones of closed forests and steppe grasslands, in which more or less closed forests alternate with closed grasslands, forming a landscape of mosaic appearance [26]. One of the main reasons for the defining of transitional life zones was specifically to determine this ecotone and estimate changes in its spatial characteristics. Each life zone’s criteria are shown by Figure 3. For ex- ample, the criteria of "boreal dry scrub" core life zone are ◦ ABT ◦ APP the followings: a. 3 C < < 6 C; b. 125 mm < PER < 250 m; c. 1 < < 2. The climate/vegetation can be identified as "subpolar subhumid moist-wet tundra" transi- tional life zone, if the following three criteria are fulfilled ABT ◦ APP simultaneously: a. < 3 C; b. 250 mm < ; c. 0.5 PER < . For the validation of classification methods the Kappa statistic [16] was used. This method has been commonly applied for comparing two vegetation maps [7, 27, 28]. The κ Kappa statistic ( ) is determined according to the following ...
Context 3
... is the potential evapotranspiration ratio [di- APE mensionless]; is the annual potential evapotranspi- APP ration [mm]; is the annual total precipitation [mm]; P(i) i the monthly total precipitation of the th month [mm]. The Holdridge life zone system is one of the best methods, which uses only temperature and precipitation data for description of the terrestrial ecosystem complexes. Each life zone type has exact definition based on the three cli- ABT, APP, PER mate indices ( ). Holdridge developed a geometric model which declares the relationship between life zones and climate indices. This geometric model - so- called the life zone chart ( Figure 2) - is a triangular coor- dinate system, in which the climate indices are depicted on logarithmic axes in recognition of Mitscherlich’s law of ABT ≈ ◦ ( 2 12+0 5) diminishing returns [6]. The of 17 C (2 ◦ ≈ ◦ C 16.97 C) was defined as a critical temperature line - so-called the frost line - which separates the warm temperate region from the subtropical region [3]. The frost line The life represents zone chart the consists dividing of line 37 between hexagons. two Each major hexagon phys- iological defines a groups life zone of which evolved is plants. named to On indicate the warmer a vegeta- side of tion the association. line, the majority Hexagons of the and plants triangles are sensitive were defined to low in temperatures [4]. ABT, APP PER the chart using guide lines of and which are denoted in Figure 2 by dashed lines. Hexagons determine core life zones; while the equilateral triangles can be termed as transitional life zones. Holdridge [4] considered also the determination of the transitional life zones, but taking into account of the large number of classes would be excessive. For this reason, each triangle was divided into three equal parts using straight lines which connect the centre of triangle to all three ver- tices. Then these smaller triangles were annexed to the adjacent hexagons which determine core life zones. As a result, larger hexagons, whose contours were denoted in Figure 2 by solid lines, appeared around the former hexagons (core life zones). These larger hexagons are the units of the original Holdridge life zone system, so-called life zones. The life zone system was developed for the tropical re- gions’ investigation [4]. The main purpose of that investigation was to better understand the relation between climate and vegetation in both mountains and lowlands. So Holdridge defined not only latitudinal regions but also ABT altitudinal belts based on the values of . He found it necessary to determine which the more important limit ABT factor of the (and thus the vegetative growth) is: a. elevation; b. distance from the Equator. On global scale the model is inapplicable for classification, when the altitudinal belts are used too, because of the number of classes would already be 117. For this reason, most studies [12, 13, 14, 15], which use Holdridge life zone model for climate classification, neglect the altitudinal belts. The life zone chart consists of 37 hexagons. Each hexagon defines a life zone which is named to indicate a vegetation association. Hexagons and triangles were defined in ABT, APP PER the chart using guide lines of and which are denoted in Figure 2 by dashed lines. Hexagons determine core life zones; while the equilateral triangles can be termed as transitional life zones. Holdridge [4] considered also the determination of the transitional life zones, but taking into account of the large number of classes would be excessive. For this reason, each triangle was divided into three equal parts using straight lines which connect the centre of triangle to all three ver- tices. Then these smaller triangles were annexed to the adjacent hexagons which determine core life zones. As a result, larger hexagons, whose contours were denoted in Figure 2 by solid lines, appeared around the former hexagons (core life zones). These larger hexagons are the units of the original Holdridge life zone system, so-called life zones. The life zone system was developed for the tropical re- gions’ investigation [4]. The main purpose of that investigation was to better understand the relation between climate and vegetation in both mountains and lowlands. So Holdridge defined not only latitudinal regions but also ABT altitudinal belts based on the values of . He found it necessary to determine which the more important limit ABT factor of the (and thus the vegetative growth) is: a. elevation; b. distance from the Equator. On global scale the model is inapplicable for classification, when the altitudinal belts are used too, because of the number of classes would already be 117. For this reason, most studies [12, 13, 14, 15], which use Holdridge life zone model for climate classification, neglect the altitudinal belts. The life zone system has been criticized that life zones don’t always coincide with observed vegetation (i.e. often the grasslands are classified as forests). One reason for this probably is that transitional life zones had not been determined by Holdridge [3, 4]. The model had been optimized for global scale. If transitional life zones were defined too, 89 life zone types (38 core life zones + 51 transitional life zones) would be determined. Namely, this large number of classes would make it impossible to visually represent the life zones. In this paper regional scale analysis was performed, so it has been considered appropriate to determine transi- tional life zones. These new units of model have been defined based on latitudinal regions (Table 2) and humidity provinces (Table 3). Transitional life zones were not distributed among life zones in contrary of the original model, but these were determined as separate units. These new classes were named according to the following steps: a. latitudinal belts and humidity provinces were determined; b. names of vegetation associations were defined as combination of two adjacent core life zones from the same latitudinal belts. The new classes’ list can be found in the legend of Figure 3. Each of transitional life zones was not defined which has got only one adjacent core life zone. Thus, only 43 transitional life zones were determined. Every transitional life zone which verges on one of the forest types (e.g. dry forest) and one of the steppe types (e.g. thorn steppe) were defined as forest steppe. The forest steppe is defined as a separate vegetation belt developed in the transitional climate between the zones of closed forests and steppe grasslands, in which more or less closed forests alternate with closed grasslands, forming a landscape of mosaic appearance [26]. One of the main reasons for the defining of transitional life zones was specifically to determine this ecotone and estimate changes in its spatial characteristics. Each life zone’s criteria are shown by Figure 3. For ex- ample, the criteria of "boreal dry scrub" core life zone are ◦ ABT ◦ APP the followings: a. 3 C < < 6 C; b. 125 mm < PER < 250 m; c. 1 < < 2. The climate/vegetation can be identified as "subpolar subhumid moist-wet tundra" transi- tional life zone, if the following three criteria are fulfilled ABT ◦ APP simultaneously: a. < 3 C; b. 250 mm < ; c. 0.5 PER < . For the validation of classification methods the Kappa statistic [16] was used. This method has been commonly applied for comparing two vegetation maps [7, 27, 28]. The κ Kappa statistic ( ) is determined according to the following ...
Context 4
... is the potential evapotranspiration ratio [di- APE mensionless]; is the annual potential evapotranspi- APP ration [mm]; is the annual total precipitation [mm]; P(i) i the monthly total precipitation of the th month [mm]. The Holdridge life zone system is one of the best methods, which uses only temperature and precipitation data for description of the terrestrial ecosystem complexes. Each life zone type has exact definition based on the three cli- ABT, APP, PER mate indices ( ). Holdridge developed a geometric model which declares the relationship between life zones and climate indices. This geometric model - so- called the life zone chart ( Figure 2) - is a triangular coor- dinate system, in which the climate indices are depicted on logarithmic axes in recognition of Mitscherlich’s law of ABT ≈ ◦ ( 2 12+0 5) diminishing returns [6]. The of 17 C (2 ◦ ≈ ◦ C 16.97 C) was defined as a critical temperature line - so-called the frost line - which separates the warm temperate region from the subtropical region [3]. The frost line The life represents zone chart the consists dividing of line 37 between hexagons. two Each major hexagon phys- iological defines a groups life zone of which evolved is plants. named to On indicate the warmer a vegeta- side of tion the association. line, the majority Hexagons of the and plants triangles are sensitive were defined to low in temperatures [4]. ABT, APP PER the chart using guide lines of and which are denoted in Figure 2 by dashed lines. Hexagons determine core life zones; while the equilateral triangles can be termed as transitional life zones. Holdridge [4] considered also the determination of the transitional life zones, but taking into account of the large number of classes would be excessive. For this reason, each triangle was divided into three equal parts using straight lines which connect the centre of triangle to all three ver- tices. Then these smaller triangles were annexed to the adjacent hexagons which determine core life zones. As a result, larger hexagons, whose contours were denoted in Figure 2 by solid lines, appeared around the former hexagons (core life zones). These larger hexagons are the units of the original Holdridge life zone system, so-called life zones. The life zone system was developed for the tropical re- gions’ investigation [4]. The main purpose of that investigation was to better understand the relation between climate and vegetation in both mountains and lowlands. So Holdridge defined not only latitudinal regions but also ABT altitudinal belts based on the values of . He found it necessary to determine which the more important limit ABT factor of the (and thus the vegetative growth) is: a. elevation; b. distance from the Equator. On global scale the model is inapplicable for classification, when the altitudinal belts are used too, because of the number of classes would already be 117. For this reason, most studies [12, 13, 14, 15], which use Holdridge life zone model for climate classification, neglect the altitudinal belts. The life zone chart consists of 37 hexagons. Each hexagon defines a life zone which is named to indicate a vegetation association. Hexagons and triangles were defined in ABT, APP PER the chart using guide lines of and which are denoted in Figure 2 by dashed lines. Hexagons determine core life zones; while the equilateral triangles can be termed as transitional life zones. Holdridge [4] considered also the determination of the transitional life zones, but taking into account of the large number of classes would be excessive. For this reason, each triangle was divided into three equal parts using straight lines which connect the centre of triangle to all three ver- tices. Then these smaller triangles were annexed to the adjacent hexagons which determine core life zones. As a result, larger hexagons, whose contours were denoted in Figure 2 by solid lines, appeared around the former hexagons (core life zones). These larger hexagons are the units of the original Holdridge life zone system, so-called life zones. The life zone system was developed for the tropical re- gions’ investigation [4]. The main purpose of that investigation was to better understand the relation between climate and vegetation in both mountains and lowlands. So Holdridge defined not only latitudinal regions but also ABT altitudinal belts based on the values of . He found it necessary to determine which the more important limit ABT factor of the (and thus the vegetative growth) is: a. elevation; b. distance from the Equator. On global scale the model is inapplicable for classification, when the altitudinal belts are used too, because of the number of classes would already be 117. For this reason, most studies [12, 13, 14, 15], which use Holdridge life zone model for climate classification, neglect the altitudinal belts. The life zone system has been criticized that life zones don’t always coincide with observed vegetation (i.e. often the grasslands are classified as forests). One reason for this probably is that transitional life zones had not been determined by Holdridge [3, 4]. The model had been optimized for global scale. If transitional life zones were defined too, 89 life zone types (38 core life zones + 51 transitional life zones) would be determined. Namely, this large number of classes would make it impossible to visually represent the life zones. In this paper regional scale analysis was performed, so it has been considered appropriate to determine transi- tional life zones. These new units of model have been defined based on latitudinal regions (Table 2) and humidity provinces (Table 3). Transitional life zones were not distributed among life zones in contrary of the original model, but these were determined as separate units. These new classes were named according to the following steps: a. latitudinal belts and humidity provinces were determined; b. names of vegetation associations were defined as combination of two adjacent core life zones from the same latitudinal belts. The new classes’ list can be found in the legend of Figure 3. Each of transitional life zones was not defined which has got only one adjacent core life zone. Thus, only 43 transitional life zones were determined. Every transitional life zone which verges on one of the forest types (e.g. dry forest) and one of the steppe types (e.g. thorn steppe) were defined as forest steppe. The forest steppe is defined as a separate vegetation belt developed in the transitional climate between the zones of closed forests and steppe grasslands, in which more or less closed forests alternate with closed grasslands, forming a landscape of mosaic appearance [26]. One of the main reasons for the defining of transitional life zones was specifically to determine this ecotone and estimate changes in its spatial characteristics. Each life zone’s criteria are shown by Figure 3. For ex- ample, the criteria of "boreal dry scrub" core life zone are ◦ ABT ◦ APP the followings: a. 3 C < < 6 C; b. 125 mm < PER < 250 m; c. 1 < < 2. The climate/vegetation can be identified as "subpolar subhumid moist-wet tundra" transi- tional life zone, if the following three criteria are fulfilled ABT ◦ APP simultaneously: a. < 3 C; b. 250 mm < ; c. 0.5 PER < . For the validation of classification methods the Kappa statistic [16] was used. This method has been commonly applied for comparing two vegetation maps [7, 27, 28]. The κ Kappa statistic ( ) is determined according to the following ...
Context 5
... is the potential evapotranspiration ratio [di- APE mensionless]; is the annual potential evapotranspi- APP ration [mm]; is the annual total precipitation [mm]; P(i) i the monthly total precipitation of the th month [mm]. The Holdridge life zone system is one of the best methods, which uses only temperature and precipitation data for description of the terrestrial ecosystem complexes. Each life zone type has exact definition based on the three cli- ABT, APP, PER mate indices ( ). Holdridge developed a geometric model which declares the relationship between life zones and climate indices. This geometric model - so- called the life zone chart ( Figure 2) - is a triangular coor- dinate system, in which the climate indices are depicted on logarithmic axes in recognition of Mitscherlich’s law of ABT ≈ ◦ ( 2 12+0 5) diminishing returns [6]. The of 17 C (2 ◦ ≈ ◦ C 16.97 C) was defined as a critical temperature line - so-called the frost line - which separates the warm temperate region from the subtropical region [3]. The frost line The life represents zone chart the consists dividing of line 37 between hexagons. two Each major hexagon phys- iological defines a groups life zone of which evolved is plants. named to On indicate the warmer a vegeta- side of tion the association. line, the majority Hexagons of the and plants triangles are sensitive were defined to low in temperatures [4]. ABT, APP PER the chart using guide lines of and which are denoted in Figure 2 by dashed lines. Hexagons determine core life zones; while the equilateral triangles can be termed as transitional life zones. Holdridge [4] considered also the determination of the transitional life zones, but taking into account of the large number of classes would be excessive. For this reason, each triangle was divided into three equal parts using straight lines which connect the centre of triangle to all three ver- tices. Then these smaller triangles were annexed to the adjacent hexagons which determine core life zones. As a result, larger hexagons, whose contours were denoted in Figure 2 by solid lines, appeared around the former hexagons (core life zones). These larger hexagons are the units of the original Holdridge life zone system, so-called life zones. The life zone system was developed for the tropical re- gions’ investigation [4]. The main purpose of that investigation was to better understand the relation between climate and vegetation in both mountains and lowlands. So Holdridge defined not only latitudinal regions but also ABT altitudinal belts based on the values of . He found it necessary to determine which the more important limit ABT factor of the (and thus the vegetative growth) is: a. elevation; b. distance from the Equator. On global scale the model is inapplicable for classification, when the altitudinal belts are used too, because of the number of classes would already be 117. For this reason, most studies [12, 13, 14, 15], which use Holdridge life zone model for climate classification, neglect the altitudinal belts. The life zone chart consists of 37 hexagons. Each hexagon defines a life zone which is named to indicate a vegetation association. Hexagons and triangles were defined in ABT, APP PER the chart using guide lines of and which are denoted in Figure 2 by dashed lines. Hexagons determine core life zones; while the equilateral triangles can be termed as transitional life zones. Holdridge [4] considered also the determination of the transitional life zones, but taking into account of the large number of classes would be excessive. For this reason, each triangle was divided into three equal parts using straight lines which connect the centre of triangle to all three ver- tices. Then these smaller triangles were annexed to the adjacent hexagons which determine core life zones. As a result, larger hexagons, whose contours were denoted in Figure 2 by solid lines, appeared around the former hexagons (core life zones). These larger hexagons are the units of the original Holdridge life zone system, so-called life zones. The life zone system was developed for the tropical re- gions’ investigation [4]. The main purpose of that investigation was to better understand the relation between climate and vegetation in both mountains and lowlands. So Holdridge defined not only latitudinal regions but also ABT altitudinal belts based on the values of . He found it necessary to determine which the more important limit ABT factor of the (and thus the vegetative growth) is: a. elevation; b. distance from the Equator. On global scale the model is inapplicable for classification, when the altitudinal belts are used too, because of the number of classes would already be 117. For this reason, most studies [12, 13, 14, 15], which use Holdridge life zone model for climate classification, neglect the altitudinal belts. The life zone system has been criticized that life zones don’t always coincide with observed vegetation (i.e. often the grasslands are classified as forests). One reason for this probably is that transitional life zones had not been determined by Holdridge [3, 4]. The model had been optimized for global scale. If transitional life zones were defined too, 89 life zone types (38 core life zones + 51 transitional life zones) would be determined. Namely, this large number of classes would make it impossible to visually represent the life zones. In this paper regional scale analysis was performed, so it has been considered appropriate to determine transi- tional life zones. These new units of model have been defined based on latitudinal regions (Table 2) and humidity provinces (Table 3). Transitional life zones were not distributed among life zones in contrary of the original model, but these were determined as separate units. These new classes were named according to the following steps: a. latitudinal belts and humidity provinces were determined; b. names of vegetation associations were defined as combination of two adjacent core life zones from the same latitudinal belts. The new classes’ list can be found in the legend of Figure 3. Each of transitional life zones was not defined which has got only one adjacent core life zone. Thus, only 43 transitional life zones were determined. Every transitional life zone which verges on one of the forest types (e.g. dry forest) and one of the steppe types (e.g. thorn steppe) were defined as forest steppe. The forest steppe is defined as a separate vegetation belt developed in the transitional climate between the zones of closed forests and steppe grasslands, in which more or less closed forests alternate with closed grasslands, forming a landscape of mosaic appearance [26]. One of the main reasons for the defining of transitional life zones was specifically to determine this ecotone and estimate changes in its spatial characteristics. Each life zone’s criteria are shown by Figure 3. For ex- ample, the criteria of "boreal dry scrub" core life zone are ◦ ABT ◦ APP the followings: a. 3 C < < 6 C; b. 125 mm < PER < 250 m; c. 1 < < 2. The climate/vegetation can be identified as "subpolar subhumid moist-wet tundra" transi- tional life zone, if the following three criteria are fulfilled ABT ◦ APP simultaneously: a. < 3 C; b. 250 mm < ; c. 0.5 PER < . For the validation of classification methods the Kappa statistic [16] was used. This method has been commonly applied for comparing two vegetation maps [7, 27, 28]. The κ Kappa statistic ( ) is determined according to the following ...
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Citations
... In particular, Holdridge's scheme (HLZ) provides a comprehensive classification system to describe both life zones and ecotones from those environmental factors. The latter feature is not present in the original formulation of the method but an enhancement through a minor adaptation 20,21 (Fig. 1a). ...
Assessing changes in the distribution of biological communities that share a climate (biomes) is essential for estimating their vulnerability to climate change. We use CMIP6 climate models to calculate biome changes as featuring in classifications such as Holdridge’s Life Zones (climate envelopes). We found that transitional zones between biomes (known as ecotones) are expected to decline under all climate change scenarios, but also that model consensus remains low. Accurate assessments of diversity loss are limited to certain areas of the globe, while model consensus is still poor for half of the planet. We identify where there are robust estimates of changes in biomes and ecotones, and where consensus is lacking. We argue that caution should be exercised in measuring biodiversity loss in the latter, but that greater confidence can be placed in the former. We find that shortcomings in the life zone classification are related to inter-model variability, which ultimately depends on a larger problem, namely the accurate estimation of precipitation compared to CRU. Application of the methodology to other climate classifications confirms the findings.
... These data are in good agreement with the previously reported paleoecological data on the mosaic environmental structure of the Carpathian Basin [145]. However, it seems that local environmental factors (micromorphology, alkaline soil, morphology, and groundwater) were extremely strong in the Kunkápolnás region, amplifying the essentially climate-driven alkalinization process (Figure 18), and therefore, the alkaline patches in the Pannonian forest-steppe region were formed on a regional scale [135,[146][147][148] under the influence of locally evolved edaphic factors. However, general alkalinization and a drier steppe phase became widespread in the region with the gradual warming of the climate from the Late Glacial to about 12,000-13,000 years, together with the process that resulted in the dominance of the Matricaria pollen type Chenopodiaceae and Artemisia pollen ( Figure 12). ...
... These data are in good agreement with the previously reported paleoecological data on the mosaic environmental structure of the Carpathian Basin [145]. However, it seems that local environmental factors (micromorphology, alkaline soil, morphology, and groundwater) were extremely strong in the Kunkápolnás region, amplifying the essentially climate-driven alkalinization process (Figure 18), and therefore, the alkaline patches in the Pannonian forest-steppe region were formed on a regional scale [135,[146][147][148] The first pastoralist cultures (Pit Grave culture = Yamnaja = Kurgan culture), which appeared around 3300 BC, only reinforced ongoing natural processes [46] but did not fundamentally transform the vegetation of the Kunkápolnás region. Similarly, there were no significant changes in the landscape character of the region over the following millennia, when the land management by domestic animals gradually increased and eventually completely took over habitat management, i.e., the grazing role of large ungulates, such as the aurochs and the European bison, which became extinct during the Holocene [149]. ...
Hungary's first national park was created in 1973 in the Hortobágy area to protect Europe's largest contiguous steppe area and its flora and fauna. The Hortobágy National Park-the Puszta was inscribed on the UNESCO World Heritage List as a cultural landscape in 1999. The park's outstanding importance is due to the predominantly non-arboreal steppe vegetation, home to a unique bird fauna, and alkaline and chernozem soils with a complex, mosaic-like spatial structure. In addition, the landscape of Hortobágy has a pastoral history stretching back thousands of years. Several hypotheses have been put forward that suggest that the alkaline soils and the habitats that cover them were formed as a result of human activities related to river regulation that began in the second half of the 19th century. However, paleoecological and paleobiological studies over the last 30-40 years have pointed to the natural origin of the alkaline steppes, dating back to the end of the Ice Age. For thousands of years, human activities, in particular, grazing by domestic animals, hardly influenced the natural evolution of the area. The drainage of marshy and flooded areas began in the 19th century, as well as the introduction of more and more intensive agriculture, had a significant impact on the landscape. This paper aims to describe the past natural development of this special alkaline steppe ecosystem, with particular reference to the impacts of past and present human activities, including conservation measures.
... These data are in good agreement with the previously reported paleoecological data on the mosaic environmental structure of the Carpathian Basin [39]. However, it seems that local environmental factors (micromorphology, alkaline soil, morphology and groundwater) were extremely strong in the Kunkápolnás region, amplifying the essentially climatedriven alkalinization process (Figure 18), and therefore the alkaline patches in the Pannonian foreststeppe region were formed on a regional scale [123,[136][137][138] under the influence of locally evolved edaphic factors. [123,[136][137][138]. ...
... However, it seems that local environmental factors (micromorphology, alkaline soil, morphology and groundwater) were extremely strong in the Kunkápolnás region, amplifying the essentially climatedriven alkalinization process (Figure 18), and therefore the alkaline patches in the Pannonian foreststeppe region were formed on a regional scale [123,[136][137][138] under the influence of locally evolved edaphic factors. [123,[136][137][138]. ...
Hungary's first national park was created in 1973 in the Hortobágy area to protect Europe's largest contiguous steppe area with its flora and fauna. The Hortobágy National Park - the Puszta was inscribed on the UNESCO World Heritage List as a cultural landscape in 1999. The park's outstanding importance is due to the predominantly non-arboreal steppe vegetation, home to a unique bird fauna, and the alkaline and chernozem soils with a complex, mosaic-like spatial structure. In addition, the landscape of the Hortobágy has a pastoral history stretching back thousands of years. Several hypotheses have been put forward, which suggest that the alkaline soils and the habitats that cover them were formed as a result of human activities related to river regulation that began in the second half of the 19th century. However, palaeoecological and palaeobiological studies over the last 30-40 years have pointed to the natural origin of the alkaline steppes, dating back to the end of the Ice Age. For thousands of years human activities, in particular grazing by domestic animals, hardly influenced the natural evolution of the area. Drainage of marshy and flooded areas began in the 19th century, and the introduction of more and more intensive agriculture, had a significant impact on the landscape. This paper aims to describe the past natural development of this special alkaline steppe ecosystem, with particular reference to the impacts of past and present human activities, including conservation measures.
... In addition to the environmental aspects, the research also delves into the historical context of the area from the Middle Ages. This historical perspective is not only valuable for historians and archaeologists interested in the region's human history and land use practices, but also gives information about the [7,8] of the vegetation of the Carpathian Basin (b) [4,[9][10][11] and the location of Lake Kolon (red circle). (c) Recent digital surface model at Izsák settlement. ...
... The climatic conditions of the area, as depicted in the Walter-Lieth diagram [2], are characteristic of forest-steppe regions [7][8][9][10][11]. The annual (2011-2022) average temperature is 12.1 • C, and the annual (2011-2022) precipitation reaches 514 mm [2]. ...
... The entire region is protected and is a part of the Little Cumanian National Park (Kiskunsági Nemzeti Park). The climatic conditions of the area, as depicted in the Walter-Lieth diagram [2], are characteristic of forest-steppe regions [7][8][9][10][11]. The annual (2011-2022) average temperature is 12.1 °C, and the annual (2011-2022) precipitation reaches 514 mm [2]. ...
The research utilizes an interdisciplinary approach, combining geological, ecological, and historical methods. It delves into the environmental evolution of Lake Kolon over a span of 17,700 years, shedding light on the intricate interplay between geological processes and ecological changes. The historical, statistical (PCA, DCA), and palaeoecological analyses centers on a core sequence situated in the heart of the lake, building upon previous research endeavors (pollen, malacological, macrobotanical and sedimentological analyses with radiocarbon dating). Forest fires occurred at the end of the Last Glacial Maximum (LGM); the boreal forest–steppe environment changed into temperate deciduous forest at the Pleistocene–Holocene boundary; human-induced environmental change into open parkland occurred; and from medieval times, communities used the land as pasture. This type of reconstruction is crucial for understanding how ecosystems respond to climate change over time, which has broader implications for modern-day conservation efforts and managing ecosystems in the face of ongoing climate change.
... The moisture province was established based on the logarithmic ranges for the PER values (Holdridge 1967) (1) PETdy = F × (RAdy∕ ) × TAdy ( Fig. 3). Life zone types were determined by considering the hexagons denoted by solid lines in Fig. 3, by using the values of the BT, P, and PER, i.e., each subdivision of a given transitional life zone type (triangle denoted by dashed lines in Fig. 3) was attached to the closest core life zone type (hexagon denoted by dashed lines in Fig. 3) (see Szelepcsényi et al. 2014). ...
Climate classification systems are tools that facilitate the analysis, grouping, delimitation, and dissemination of the climatic characteristics of a region, contributing to the circumscribing of areas suitable for the agriculture and to the validation of various models of climate change. In this study, Brazilian life zone types were identified by using the initial variant of the well-known Holdridge eco-climatological classification, under different climate change scenarios. To describe current conditions in Brazil, daily time series of temperature and precipitation for the period 1989–2019 are used, derived from the National Aeronautics and Space Administration/Prediction of Worldwide Energy Resources (NASA/POWER) platform. Climate change was considered through four alternative scenarios. According to the original classification, under current conditions, the dominant life zone type is the type tropical basal moist forest, covering 60.57% of the country. An increase in temperature can cause a decrease in the dominance of this life zone type, though approximately half of the country may be covered by this type. Furthermore, in case of an increase of 3 °C, the type tropical basal dry forest could already cover a third of Brazil. An increase of 30% in precipitation could cause the emergence of several new life zone types, while the extent of the type tropical basal moist forest could then decrease to 50.12%. Due to the high variability of the life zone types obtained, the Holdridge system can be considered a useful tool to illustrate climate change impacts.
... = Madaras brickyard, II. = borehole in the Lake Kolon; A = Inner Somogy, B = Little Cumania, C = Nyírség, D = Bácska loess plateau, E = Deliblat; 1 = Vojvodina (Vajdaság) loess area, 2 = Stem Loess plateau, 3 = Titel Loess plateau, 4 = Temes Loess plateau, 5 = Banat Loess plateau, 6 = Hajdúság region) and Holdridge modified bioclimatic areas of the Carpathian Basin and Carpathians, Alps, Dinaric Alps (Szelepcsényi et al., 2014(Szelepcsényi et al., , 2018 (1 = subpolar humid drymoist tundra, 2 = subpolar perhumid moist-wet tundra, 3 = subpolar superhumid moist-wet tundra, 4 = subpolar subhumid drymoist tundra, 5 = subpolar humid moist-wet tundra, 6 = subpolar perhumid wetrain tundra, 7 = boreal subhumid desertdry scrub, 8 = boreal humid dry scrubmoist forest, 13 = boreal humid moist wet forest, 14 = boreal perhumid wet-rain forest, 15 = cool temperate semiarid desertdesert scrub, 16 = cool temperate subhumid desert scrubsteppe, 17 = cool temperate subhumid forest steppe, 18 = cool temperate perhumid moist-wet forest, 19 = cool temperate subhumid wet-rain forest, 20 = cool temperate arid desertdesert scrub, 21 = cool temperate subarid desert scrubsteppe, 22 = cool temperate subhumid forest steppe, 23 = cool temperate humid moist-wet forest, 24 = cool temperate perhumid moist-wet forest). ...
... There is a drastic fall in total biomass in the transition zone between the actual woodland and the tree line from ca. 20 kg/m 2 to 0.6 kg/m 2 due to the replacement of trees by smaller bushes and non-arboreal elements (Stevens and Fox, 1991). Based on the bioclimatic models (Szelepcsényi et al., 2014(Szelepcsényi et al., , 2018, the decrease of the humidity limiting the spread of the trees in the Carpathian Basin caused the development of the Pannonian forest-steppe region, this unusually wide ecotone. Therefore, the emergence of transitionary zones between woodlands and grasslands is generally controlled by the availability of humidity as a limiting factor (Szelepcsényi et al., 2014(Szelepcsényi et al., , 2018. ...
... Based on the bioclimatic models (Szelepcsényi et al., 2014(Szelepcsényi et al., , 2018, the decrease of the humidity limiting the spread of the trees in the Carpathian Basin caused the development of the Pannonian forest-steppe region, this unusually wide ecotone. Therefore, the emergence of transitionary zones between woodlands and grasslands is generally controlled by the availability of humidity as a limiting factor (Szelepcsényi et al., 2014(Szelepcsényi et al., , 2018. The origin of this modern unusually wide woodland-grassland transition, the Pannonian forest-steppe region, which covers an area of ca. ...
In the present work, well radiocarbon-dated Quaternary malacological and palynological analyses were implemented on 4 cm samples deriving from one of the thickest and best developed last glacial sequences of Central Europe the Madaras brickyard and the borehole of Kolon Lake in the southern part of Hungary. Using a combination of mollusc, anthracological, palynological and climatic proxies evidence preserved within loess, we demonstrate that long-term changes (e.g. the last 39,000 (28,000) years) in paleoclimatic dynamics on the northern edge of the Bácska-Titel loess plateau, on the southern part of the Great Hungarian Plain. These proxy data are reflected in the following ecological changes: a turnover from predominantly cold-tolerant mollusc fauna in a boreal type forest-steppe context under cold conditions during the last glacial then followed by a shift to a predominantly xerotheromphilous land snail fauna in a temperate forest-steppe context under a warm temperate climate in the early Holocene. Certain warm-adapted, Central and SSE European distribution mollusc species such as Caucasotachea vindobonensis and Granaria frumentum, were found to have been associated with temperate forest-steppe in both the Holocene record and the present-day ecosystem.
Data availability
The data that support the findings of this study are available from the corresponding author upon reasonable request.
... First, we divided grid cells into cold and warm regions with a threshold of average annual temperature of 17.3°C. This threshold was derived from a recent similar study about the effects of urbanization on remotely sensed plant phenology (Meng et al., 2020); it is also close to the frost line (17°C) that separates temperate and subtropical regions (Szelepcsényi et al., 2014). ...
Aim
Urbanization is becoming one of the most important drivers of global environmental change as human population and economic development rapidly increase. However, the effects of urbanization on plant phenology are still poorly understood, especially for leaf senescence and growing season length across large spatial scales. We aimed to fill this knowledge gap by combining in situ observations and remote sensing phenological data.
Location
The United States and Europe.
Time period
2009–2018.
Major taxa studied
Vascular plants.
Methods
We divided the United States and Europe into 10 km by 10 km grid cells. We estimated leaf senescence dates for 93 species, and growing season length for a subset of 54 of these species, for grid cells with enough data using a database with >22 million in situ phenology observations. We also estimated growing season lengths at the community level for the Eastern Temperate Forest ecoregion in the US using remote sensing data. We then investigated effects of urbanization (using human population density as a proxy), temperature, and their interactions on leaf senescence and growing season lengths using linear mixed models.
Results
Urbanization and warmer regional temperature both delayed plant leaf senescence. In addition, the effects of urbanization on leaf senescence and growing season lengths depended on climate context: urbanization delayed leaf senescence and extended growing season length in cold regions; however, urbanization advanced leaf senescence and shortened growing season length in warm regions, implying the positive effects of urbanization on growing season length in cold regions may be weaker in a warmer future.
Main conclusions
Our study provides strong empirical evidence that the influence of urbanization on plant phenology and growing season length varies with regional temperature. Our results have important implications for predicting plant phenology and growing season length in a warmer and more urbanized future.
... Maximum rainfall occurs in June (67 mm/month), with August on average the driest month (34 mm/month). It belongs to cool temperate subhumid forest steppe biome under the Holdridge's life zones system (Szelepcs enyi et al., 2014), with predominantly luvisol, vertisol, and chernozem style soils (European Soils Bureau, 2005). The southern bank of the Danube River preserves between two and six Pleistocene to Pliocene river terraces (Evlogiev, 2007) on top of which thick LPS (15e30 m) that form small plateaus are preserved. ...
In Central and Eastern Europe, research has been focused on loess associated with a plateau-setting, which preserves distinct and well-developed loess and palaeosol units linked to orbital scale changes. This has led to the view that during the last glacial period the Middle and Lower Danube predominantly experienced dry continental climates and supported steppic environments. However outside of the typical plateau setting, some authors have reported a presence of embryonic palaeosols within loess units suggesting sufficient moisture for short-term pedogenesis, and therefore either large scale moisture delivery systems and/or influence of local climatic and/geomorphic factors. Here the palaeoenvironmental and palaeoclimatic history is reconstructed based on two loess-palaeosol profiles in Slivata, North Bulgaria. The site is located in proximity to both the Carpathian and Balkan Mountains and rest on the Danube river terrace. To understand the timing of sediment deposition and dust fluxes chronological approaches combining quartz optically stimulated luminescence (OSL), feldspar post infrared-infrared stimulated luminescence (pIR-IRSL), and tephra correlation were applied. The results are coupled with high-resolution particle size and magnetic susceptibility analysis to provide an overview of past environmental conditions at the site. Finally, zircon U–Pb ages are used to understand potential changes to sediment delivery patterns, in the context of the site development.
The investigated profile at Slivata 2 preserves a loess-palaeosol record spanning 52–30 ka, with a very complex sedimentary sequence that switches between periods of enhanced dust flux and sediment accumulation, and palaeosol development. The Slivata 2 sequence is also punctuated by multiple thin “palaeosol” like units that are interpreted as colluvial “soil” deposits on the basis of sedimentology, provenance, and geochronology, indicating a highly variable and dynamic landscape responding to the surrounding environment. The chronology shows very rapid sediment accumulation at Slivata 1 during LGM, with mass accumulation rates similar to sites in the Carpathian Basin, suggesting strong winds and high sediment supply rates. Yet LGM loess is punctuated by a thin palaeosol, which developed between 20–19 ka. This coincides with a temporary glacial retreat in the Carpathian Mountains and higher moisture availability in Eastern Carpathians, and therefore points to localised influences on loess-palaeosol development. Moreover data from Slivata 1 shows soil development and by extension landscape and climate stabilisation shortly prior to 14 ka. The pre-Holocene onset of pedogenesis at Slivata supports ecological and glacial evidence of weak Younger Dryas from the South Carpathian Mountains.
Lastly this paper provides a geochemical analysis of the thin tephra horizon preserved in the Slivata 2 profile, which was correlated to the Cape Riva/Y-2 tephra. Consequently Slivata is the most northerly terrestrial site found to contain this tephra horizon, which has implications for the understanding of the size of the Santorini's Cape-Riva/Y-2 explosion. The identification of the Cape Riva (Y-2) tephra horizon and new remodelled age of 21.92 ± 0.56 cal ka BP provides a new tephrostratigraphic marker for eastern European LGM loess.
... However, we set the upper threshold to 35 • C because, in view of progressive global warming, plants may adapt, especially in tropical zones (Holdridge and Grenke, 1971;Jump and Penuelas, 2005;Colwell et al., 2008), whereas the lower threshold is unchanged as for plants it is more difficult to adapt to cold climates (Körner and Larcher, 1988). The number of classes in the HDG system ranges between thirty-one and thirty-six, due to a variable number of subdivisions for cold climate (Szelepcsényi et al., 2014). In this study, to delineate arid areas using HDG, we selected the sub-classes desert, desert scrub, thorn woodland, thorn steppe, and very dry forest (see the naming scheme in Lugo et al. (1999). ...
One of the possible consequences of projected global warming is the progressive enlargement of drylands. This study investigates to what extent population and land-use (forests, pastures, and croplands) are likely to be in areas turning arid in the 21st century. The first part of the study focuses on the climatological enlargement of arid areas at global, macro-regional, and high-resolution (0.44°) scales. To do so we analysed a large ensemble of CORDEX climate simulations, combined three indicators (FAO-UNEP aridity index, Köppen-Geiger climate classification, and Holdridge life zones), and quantified the areas turning from climatologically not arid into climatologically arid (and vice-versa) from recent past (1981–2010) to four projected global warming levels (GWLs) from 1.5°C to 4°C. In the second part, we used population and land-use projections to analyze their exposure to progressive shifts to drier or wetter climate. Both types of projections follow five socio-economic scenarios (SSPs from SSP1 to SSP5). We present results for the viable combinations between SSPs and GWLs. Depending on GWL, the projected drying patterns show regional differences but, overall, the negative consequences of climate change are clear. Already at 1.5°C warming, approximately 2 million km2 (1.4% of global land) are likely to become arid; at 2°C this area corresponds to 2.6 million km2 (2.7%), at 3°C to 5.2 million km2 (3.5%), and at 4°C to 6.8 million km2 (4.5%), an area that can be ranked the seventh largest country in the World. Such drying is particular strong over South America and southern Europe. In the worst-case scenario (SSP3, regional rivalry, at 4°C), approximately 500 million people will live in areas shifting towards arid climate. Forest areas are likely to be more affected in South America, pastures in Africa, and croplands in the Northern Hemisphere. For land-use, the worst-case scenarios are SSP3 and SSP5 (fossil-fuel based future): at GWL 4°C, about 0.5 million km2 of forests and 1.2 million km2 of both pastures and croplands are likely to be in areas shifting to arid climate.
... One of the most widely known of these methods is the Holdridge life zone (HLZ) system (Holdridge 1947(Holdridge , 1967. In recent years, especially since the early 1990s, this scheme has been increasingly used to map climate change's impact at both global (e.g., Emanuel et al. 1985;Leemans 1990;Sisneros et al. 2011) and regional scales, for example, in Europe (Szelepcsényi et al. 2014(Szelepcsényi et al. , 2018, Eurasia (Fan and Fan 2019;Fan et al. 2019), China (Chen et al. 2003;Yue et al. 2006;Zhang et al. 2011), and Central America (Khatun et al. 2013;Khalyani et al. 2016). In addition, this technique is still frequently used to understand the ecology of tropical areas (Sabino et al. 2019;Tres et al. 2020), but its paleoecological application has also recently appeared (Sümegi et al. 2012(Sümegi et al. , 2015(Sümegi et al. , 2016. ...
... In some regions, a high overlap was found between their HLZ map and maps of forest formations and ecological provinces, but a relatively poor correlation was observed in transitional areas between warm temperate and boreal regions. Szelepcsényi et al. (2014) validated the HLZ system by using an expert-based map of the potential (natural) vegetation. Depending on the reclassification rules, a poor to fair match was found, but the horizontal resolution and spatial coverage of their maps are very low. ...
... A hexagon representing each life zone is subdivided by thresholds of the bioclimatic variables into a set of one smaller hexagon and six small triangles. The small hexagon indicates the so-called core zone, while by merging three adjacent small triangles, the so-called transitional life zone is obtained (see Fan et al. 2013;Szelepcsényi et al. 2014). ...
The Holdridge life zone (HLZ) method is applied to map potential vegetation types in Turkey. The HLZ map is compared to a map of actual vegetation in order to assess the degradation status of vegetation in Turkey. Data required to identify HLZ classes are provided by the General Directorate of Meteorology, while the current vegetation status is estimated with data provided by the General Directorate of Forestry. After weather data are cleaned and missing values are replaced, the HLZ type is estimated for each station, and then thematic maps are created using the ArcGIS software. The study reveals that there are 12 HLZ types in Turkey. The three dominant types are as follows: cool temperate steppe, warm temperate dry forest, and cool temperate moist forest. In regions where physical geographical controls change in short distances, the biodiversity is greater, and linked to this, the HLZ diversity also appears to be greater. Comparing the identified life zones to the actual vegetation, in some areas, remarkable mismatches can be found. Although, in some regions, the life zone type is consistent with the land cover type, in some narrow areas, the potential vegetation does not reflect features of the current vegetation cover. Considering limitations and capabilities of the assessment approach used in this study, we think that the incompatibility between actual and modelled vegetation types in the eastern region of Turkey is caused by the intensive landscape use. The goal of this research is to support future bioclimatic studies and land use management strategies.
