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Seed production (mean ? SE) of C 4 grass species in the central Monte desert during growing seasons 2001–2002 (GS1), 2002–2003 (GS2) and 2003–2004 (GS3). Seed production is measured as the mean number of seeds per plant (n = 10) for the summer months February and April. Different letters indicate significant differences between growing seasons' seed production (Kruskal–Wallis tests and a posteriori Dunn's tests)
Source publication
In desert regions, water availability triggers primary production, which determines seed production, the composition and size
of soil seed reserves and the abundance and behaviour of seed-eating animals. In the central Monte desert, large precipitation
events (≥10mm) account for a high proportion of growing season’s rainfall. Our first objective he...
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Citations
... Hampton et al. [28] found that tiller production of perennial ryegrass was optimal at 18-24℃ but that higher temperatures depressed tiller production and seed yield. Pol et al. [33] suggested that perenniality could enable perennial grasses to make large reproductive investments despite harsh environmental conditions. However, little is known about the year-to-year variation in seed yield of L. chinensis growing in a finite space within the same habitat [34,35]. ...
Background and aims
The escalating issue of soil saline-alkalization poses a growing global challenge. Leymus chinensis is a perennial grass species commonly used in the establishment and renewal of artificial grasslands that is relatively tolerant of saline, alkaline, and drought conditions. Nonetheless, reduced seed setting rates limit its propagation, especially on alkali-degraded grassland. Inter-annual variations have an important effect on seed yield and germination under abiotic stress, and we therefore examined the effect of planting year on seed yield components of L. chinensis.
Methods
We grew transplanted L. chinensis seedlings in pots for two (Y2), three (Y3), or four (Y4) years and collected spikes for measurement of seed yield components, including spike length, seed setting rate, grain number per spike, and thousand seed weight. We then collected seeds produced by plants from different planting years and subjected them to alkaline stress (25 mM Na2CO3) for measurement of germination percentage and seedling growth.
Results
The seed setting rate of L. chinensis decreased with an increasing number of years in pot cultivation, but seed weight increased. Y2 plants had a higher seed setting rate and more grains per spike, whereas Y4 plants had a higher thousand seed weight. The effects of alkaline stress (25 mM Na2CO3) on seed germination were less pronounced for the heavier seeds produced by Y4 plants. Na2CO3 caused a 9.2% reduction in shoot length for seedlings derived from Y4 seeds but a 22.3% increase in shoot length for seedlings derived from Y3 seeds.
Conclusions
Our findings demonstrate significant differences in seed yield components among three planting years of L. chinensis under pot cultivation in a finite space. Inter-annual variation in seed set may provide advantages to plants. Increased alkalinity tolerance of seed germination was observed for seeds produced in successive planting years.
... Usually, both dormant and non-dormant seeds are present in soil seed banks and consequently increases the chances of species persistence by synchronizing the germination timing with favorable seasons or in the absence of enough seed production during a particular year [17][18][19]. Since seed production in the desert is usually inconsistent and low due to scanty and irregular rainfall events [20,21], understanding the ability of desert species to form a soil seed bank could be important for designing restoration and conservation plans. Here the natural vegetation has been already degraded as a result of several factors such as overgrazing, off-road driving, and camping [22]. ...
... Additionally, retaining dormancy could promote species persistence under desert conditions by assisting in (i) synchronizing the germination timing with favorable seasons, (ii) the formation of seedbanks, and (iii) reducing the competition for resources (i.e., nutrients and water) at the seedling proliferation stage [51,54]. Generally, seed production in deserts is erratic and low due to scanty and irregular rainfall events [21]; therefore, forming seed banks could be the adaptation strategy to survive under such conditions, especially when the production of seeds may be reduced for long periods. Moreover, the lower germination of fresh seeds has been suggested as a survival strategy that ensures species persistence by the formation of soil seed banks, even with the repeated droughts that usually occur in desert environments [55,56]. ...
Citation: Suleiman, M.K.; Bhatt, A.; Jacob, S.; Thomas, R.R.; Sivadasan, M.T. Seed Longevity in Desert Species and the Possibility of Forming a Persistent Soil Seed Bank. Sustainability 2023, 15, 15904.
... Continuous and extensive grazing causes minor changes in the cover and structure of woody vegetation, but it significantly reduces the cover and seed abundance of herbaceous species, especially perennial grasses consumed by livestock (Gonnet, 2001;Marone et al., 2017;Pol et al., 2014Pol et al., , 2017Sagario et al., 2020). In addition, high rainfall variability is associated with inter-annual changes in herbaceous plant cover and seed production, resulting in marked temporal fluctuations in the abundance and composition of the soil seed bank (Blendinger & Ojeda, 2001;Marone & Pol, 2021;Pol et al., 2010). The combined effect of grazing and rainfall variability may further reduce the availability of seeds in the soil bank, particularly of perennial grasses that are highly consumed and preferred by granivorous ants (Marone & Pol, 2021;Pirk, di Pasquo, & Lopez de Casenave, 2009;Pirk & Lopez de Casenave, 2006. ...
Some species are severely affected by global change, whereas others can survive or even thrive under the same circumstances. Species with more flexible behaviours can better cope with changes in the environment than those with more stereotyped behaviours; therefore, knowing the limits of behavioural flexibility is critical to predict their responses to global change.
Livestock grazing is the most widespread land use in deserts and a major driver of vegetation change. In turn, unpredictable and sporadic rainfall can increase the negative impact of grazing. The interaction of both factors is more relevant nowadays as a consequence of climate change.
In the central Monte desert, cattle grazing and inter‐annual variations in rainfall reduce the abundance of seeds preferentially consumed by granivorous animals. There we analysed the dietary flexibility of the specialist harvester ant Pheidole spininodis in response to inter‐annual variations in seed availability during four consecutive years at sites with contrasting grazing pressure.
Pheidole spininodis expanded its diet by including other items and decreasing seed consumption as seed availability decreased over the years, but this response did not differ between grazing conditions, probably because the drastic reduction in seed abundance at the regional scale blurred the contrast between grazed and ungrazed sites.
Our results highlight the potential dietary flexibility of a specialist species that, under adverse conditions, can modify its diet. Future studies should investigate whether these changes in the diet of P. spininodis in contexts of low resource availability may have negative effects on its survival, as previously reported for other granivorous species.
... We suspect that the proportion of developed seeds per flowerhead is normal for this species, as the number of developed seeds a plant produced was largely dependent on flower morphology associated with a species (Landeen et al. 2017). The development of seeds may also be affected by pollination success (Etcheverry et al. 2008) and environment limitations such as nutrients, temperature (Young et al. 2004), and water availability (Pol et al. 2010). We suspect that A. simplex may have produced fewer viable seeds in 2021 than in 2020 because of less precipitation in the second year. ...
Artemisia simplex (Laramie chickensage) is an imperiled, endemic plant in southeastern Wyoming, USA. To fill critical information gaps, we measured its seed viability and pollination mechanisms, measures that are lacking for many rare and endemic plants yet critical for the perpetuation of species. Artemisia simplex cover varied among sites and occupied 5.5% (range: 1.3–14.6%) of the area on average. This unique plant typically produced viable seeds under ambient conditions but did not self‐pollinate. Characteristics of the flower and pollen suggest that A. simplex is primarily animal‐pollinated, and we found that both wind and animals transported pollen to the plant, but wind alone produced fewer seeds. Members of the sagebrush genus are widely known to be wind‐pollinated; however, we demonstrated that this species of sagebrush is largely animal‐pollinated. Plant conservation and management plans must consider the mode of pollen transfer, especially when considering the decline of insect pollinators. Pollination provides information about the persistence of plant populations through sexual reproduction, which produces the genetic variation needed for healthy populations.
... The findings for MaxEnt indicated that the precipitation of the warmest quarter (Bio 18) had the greatest effect on the distribution of all Meconopsis species amongst the 11 environmental variables involved in modeling, and this is consistent with our previous study in Minjiang headwater region [42]. Since precipitation can affect plant growth, morphology, phenology, and biomass accumulation [62][63][64][65][66], in particular for seedling emergence and establishment [67], an appropriate degree of precipitation can supply sufficient water and promote plant growth; however, excessive rainfall can deteriorate the soil permeability [68], creating an anaerobic environment that inhibits the regular respiration of roots [69], and limits plant growth and development by influencing their metabolism [70]. Moreover, waterlogging can also cause stomata to close and photosynthesis to decrease, and increases the energy consumption for respiration, affecting the accumulation of organic matter [71]. ...
Understanding the potential habitat of Meconopsis, their species richness distribution patterns, and their influencing factors are critical for the conservation and rational exploitation of this valuable resource. In this study, we applied the MaxEnt model to predict their potential distribution, mapped the distribution pattern of species richness, and analyzed the variation of species richness along environmental gradients. Finally, we calculated the landscape fragmentation indices between the five subregions. Our results found that: (1) the medium- and high-suitable habitats of Meconopsis were mainly distributed in the central and eastern Himalaya, the Hengduan Mountains, and the southeast edge of the plateau platform, with suitable habitats ranged from 3200 m to 4300 m, whose most important factor is precipitation of the warmest quarter; (2) species richness showed a hump pattern along the environmental gradients except for longitude that showed an increasing trend, mainly concentrated in the south and southeast; and (3) the subregions are in the descending order of species richness: plateau platform, Hengduan Mountains, central, eastern, and western Himalaya; the highest and lowest degree of landscape fragmentation were in the western Himalaya and eastern Himalaya, respectively. Our study provides a theoretical background for the conservation and sustainable exploitation of Meconopsis in the wild.
... Such full and rapid recovery of grassland communities was often triggered by an increase in the abundance of nonnative plants (Valliere et al., 2017;Xu et al., 2017b). We also found evidence for a population decline of species during an extreme event followed by either over- (Pol et al., 2010) or underrecovery (Rondeau et al., 2013;Zwicke et al., 2013). ...
Anthropogenic climate change is increasing the incidence of climate extremes. Consequences of climate extremes on biodiversity can be highly detrimental, yet few studies also suggest beneficial effects of climate extremes on certain organisms. To obtain a general understanding of ecological responses to climate extremes, we present a review of how 16 major taxonomic/functional groups (including microorganisms, plants, invertebrates, and vertebrates) respond during extreme drought, precipitation, and temperature. Most taxonomic/functional groups respond negatively to extreme events, whereas groups like mosses, legumes, trees, and vertebrate predators respond most negatively to climate extremes. We further highlight ecological recovery after climate extremes are challenging to predict purely based on ecological responses during or immediately after climate extremes. By accounting for the characteristics of the recovering species, resource availability, and species interactions with neighbouring competitors or facilitators, mutualists, and enemies, we outline a conceptual framework to better predict ecological recovery in terrestrial ecosystems.
... Our study found that the distribution of M. punicea was mainly controlled by three precipitation-related bioclimatic variables (Bio 18: precipitation of warmest quarter; Bio 13: precipitation of wettest month; Bio 15: precipitation seasonality), two temperaturerelated bioclimatic variables (Bio 4: temperature seasonality; Bio 7: annual temperature range), and soil type. Changes in precipitation patterns due to climate change can affect plant physiological and ecological processes at different scales (Barker et al., 2006;Tognetti et al., 2007), including plasticity response of vegetative growth (Heisler-white et al., 2009) and reproductive growth (Molina-Montenegro et al., 2010;Pol et al., 2010) characteristics of plants. In addition, precipitation can affect soil moisture and nutrient availability, thus regulating plant growth and development (Brant and Chen, 2015). ...
Meconopsis punicea is an iconic ornamental and medicinal plant whose natural habitat has degraded under global climate change, posing a serious threat to the future survival of the species. Therefore, it is critical to analyze the influence of climate change on possible distribution of M. punicea for conservation and sustainable utilization of this species. In this study, we used MaxEnt ecological niche modeling to predict the potential distribution of M. punicea under current and future climate scenarios in the southeastern margin region of Qinghai-Tibet Plateau. Model projections under current climate show that 16.8% of the study area is suitable habitat for Meconopsis. However, future projections indicate a sharp decline in potential habitat for 2050 and 2070 climate change scenarios. Soil type was the most important environmental variable in determining the habitat suitability of M. punicea, with 27.75% contribution to model output. Temperature seasonality (16.41%), precipitation of warmest quarter (14.01%), and precipitation of wettest month (13.02%), precipitation seasonality (9.41%) and annual temperature range (9.24%) also made significant contributions to model output. The mean elevation of suitable habitat for distribution of M. punicea is also likely to shift upward in most future climate change scenarios. This study provides vital information for the protection and sustainable use of medicinal species like M. punicea in the context of global environmental change. Our findings can aid in developing rational, broad-scale adaptation strategies for conservation and management for ecosystem services, in light of future climate changes.
... This can be explained by the annual die-off of the aboveground parts of Poaceae, whereas of the members of Asteraceae and Amaranthaceae are perennials (shrubs and trees). It has been reported annual parts of plants are less able to adapt to droughts during vegetation periods compared to perennial ones, which store chemical elements (Cleland et al. 2013;Pol et al. 2010). Thus, with climate desiccation, plants invest more heavily not in the biomass of annual parts (Bonser and Aarssen 2006;Van Kleunen 2007), but rather in accelerating reproductive maturation to produce seeds before the end of the favourable period (Franks et al. 2007;Hall and Willis 2006). ...
Background and aimsWe assessed biomass variability and uptake of major and trace elements in different plant families of steppe landscapes under conditions of the geochemical properties of soils and the climatic parameters variability. The data obtained will contribute to a better understanding of the geochemical function of plants in steppes, which is crucial for predicting the response of landscapes to climate change.Methods
Plant and soil samples were taken in different types of dry steppes (southeast of Russia) along a climatic gradient. In the obtained samples, the contents of Ca, K, Al, S, Mg, P, Cl, Fe, Ti, Zn, Mn, Cr, Sr, Ba and Rb were determined. Soil grain size, pH, carbonates (CaCO3) and soil organic carbon (SOC) were determined.ResultsIncreased mean annual precipitation and decreased temperatures contributed to the predominance of graminoid species, thus facilitating the accumulation of the studied major and trace elements in the upper soil horizons. Climate desiccation promoted the growth of wormwood and goosefoot in the ground cover, increased the alkalisation of the upper soil horizons and contributed to the accumulation of Ca, K, P, S and Cl by these plants. The contribution of plants to the total contents of Rb, Ti, Fe, Ca, P, Mg and S in the soil was higher in arid landscapes, where the ground cover was dominated by Asteraceae and Amaranthaceae, which may promote the accumulation of those elements in the upper soil horizons under the increasing trend of desiccation.Conclusions
Our data confirm that the biodiversity of steppe vegetation, that is mainly determined bythe ratio of heat and moisture, affects the chemical properties of soils. This should be taken into account when assessing the environmental effects of further climate warming, given that desiccation will cause an increase in the contents of Ca, K, P, S and Cl in plants and soils.
... Pappophorum spp. Produces twice as much seeds in humid than in dry years (Pol et al., 2010). However, Pol et al. (2010) also reported that among seven warm-season perennial grass species, Trichloris crinita was the only one that significantly produced more seed in a dry than in a humid year in the region of the Central Monte in Argentina. ...
... Produces twice as much seeds in humid than in dry years (Pol et al., 2010). However, Pol et al. (2010) also reported that among seven warm-season perennial grass species, Trichloris crinita was the only one that significantly produced more seed in a dry than in a humid year in the region of the Central Monte in Argentina. ...
Arid zones, where native rangelands are common, are essentials for millions of people livelihood. These areas support 50% of the world's livestock and are where 44% of the world's food is grown. In rangelands of Central Argentina, Pappophorum vaginatum is basically the unique, warm-season perennial grass species palatable to grazing livestock. Our major objective was to determine variability in reproductive characteristics among four spontaneous, overgrazed populations (i.e., P1, P2, P3, P4) of that species to identify promissory materials for domestication. Studies were conducted during three consecutive growing seasons within the southwestern part of the Phytogeographical Province of the Monte, in southwestern Buenos Aires, Argentina. Measured reproductive characteristics were related to flowering initiation, seed production and natural reseeding potential. Significant differences were found for flowering initiation and natural reseeding potential, but not for viable anthecia per plant among the four populations of P. vaginatum. This species fructified from the beginning to the end of the studied growing seasons with a great anthecia production per plant. The light weight of these anthecia and their awns would favor a great wind dispersal and most likely the establishment of new seedlings of P. vaginatum. This suggests that sexual reproduction might have a relatively greater importance than asexual reproduction (i.e., tillering) in the persistence of the overgrazed P. vaginatum in the plant communities of the studied region. Selection of plant materials with a late flowering initiation will allow to extend the forage production of a better quality. The variability among and within populations found on this study support the idea that would be promissory to start selection programs to obtain improved germplasm to reincorporate to grasslands of the south of the Phytogeographical Region of the Monte (Argentina) not only to increase livestock production but to recover and maintain biodiversity.
... Such full and rapid recovery of grassland communities was often triggered by an increase in the abundance of nonnative plants (Valliere et al., 2017;Xu et al., 2017b). We also found evidence for a population decline of species during an extreme event followed by either over- (Pol et al., 2010) or underrecovery (Rondeau et al., 2013;Zwicke et al., 2013). ...
