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Fig. S4. Preston plots showing the observed frequency of species in octaves of abundance (bars) and the predicted frequency by four different SAD models (blue line) for the global data set.
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You can download the whole book here: http://www.in-tree.org/uploads/images/book/Introduced_tree_species_EN_HighRes.pdf
Citations
... Most tropical tree species are rare and old-growth forest specialists (Slik et al., 2015) and, thus, potentially threatened with extinction (ter Steege et al., 2022). Also, most tropical tree species are shade-tolerant (Clark & Clark, 1992) and long-lived (>100 years; Martínez-Ramos & Alvarez-Buylla, 1998). ...
Tropical tree species are increasingly being pushed to inhabit deforested landscapes. The habitat amount hypothesis posits that, in remaining forest patches, species diversity in equal‐sized samples decreases with decreasing forest cover in the surrounding landscape. We tested this prediction by taking into account three important factors that can affect species responses to forest loss. First, forest loss effects can be linear (proportional) or nonlinear, as there can be threshold values of forest loss beyond which species extirpation may be accelerated. Second, such effects are usually scale dependent and may go unnoticed if assessed at suboptimal scales. Finally, species extirpation may take decades to become evident, so the effects of forest loss can be undetected when assessing long‐lived organisms, like adult old‐growth forest trees. Here, we evaluated the linear and nonlinear effects of landscape forest loss across different spatial scales on site‐scale abundance and diversity of old‐growth forest trees, separately for four plant‐life stages (seeds, saplings, juveniles, and adults) in two rainforest regions with different levels of deforestation. We expected stronger (and negative) forest loss effects on early plant‐life stages, especially in the region with the highest deforestation. Surprisingly, in 13 of 16 study cases (2 responses × 4 life stages × 2 regions), null models showed higher empirical support than linear and nonlinear models at any scale. Therefore, the species richness and abundance of local tree assemblages seem to be weakly affected by landscape‐scale forest loss independently of the spatial scale, life stage, and region. Yet, as expected, the predictive power of forest cover was relatively lower in the least deforested region. Our findings suggest that landscape‐scale forest loss is poorly related to site‐scale processes, such as seed dispersal and seedling recruitment, or, at least, such effects are too small to shape the abundance and diversity of tree assemblages within forest patches. Therefore, our findings do not support the most important prediction of the habitat amount hypothesis but imply that, on a per‐area basis, a unit of habitat (forest) in a highly deforested landscape has a conservation value similar to that of a more forested one, particularly in moderately deforested rainforests.
... However, whether such patterns hold in other tropical forests is unknown, as there have been no comparable analyses for African or Southeast Asian tropical forests. Perhaps, given the substantial differences in total tree species richness 25 , forest structure 1 , contemporary climate 26 and biogeographic and human-occupancy histories 7 among continents, important contrasts in patterns of common species would be expected. Alternatively, if the same processes or mechanisms apply to all tropical forests 27 , highly consistent patterns may be expected. ...
... This minimum estimate does not account for species that are yet to be identified and described by scientists. An alternative extrapolation method estimated that there are 46,900 species for the closed canopy tropical forest biome 25 (range 40,500-53,300 species), implying that there are 9,000 yet-to-be-identified species. This is in agreement with a recent global study suggesting that there are around 9,200 tree species remaining yet to be formally named, almost all in the tropics 16 . ...
Trees structure the Earth’s most biodiverse ecosystem, tropical forests. The vast number of tree species presents a formidable challenge to understanding these forests, including their response to environmental change, as very little is known about most tropical tree species. A focus on the common species may circumvent this challenge. Here we investigate abundance patterns of common tree species using inventory data on 1,003,805 trees with trunk diameters of at least 10 cm across 1,568 locations1–6 in closed-canopy, structurally intact old-growth tropical forests in Africa, Amazonia and Southeast Asia. We estimate that 2.2%, 2.2% and 2.3% of species comprise 50% of the tropical trees in these regions, respectively. Extrapolating across all closed-canopy tropical forests, we estimate that just 1,053 species comprise half of Earth’s 800 billion tropical trees with trunk diameters of at least 10 cm. Despite differing biogeographic, climatic and anthropogenic histories⁷, we find notably consistent patterns of common species and species abundance distributions across the continents. This suggests that fundamental mechanisms of tree community assembly may apply to all tropical forests. Resampling analyses show that the most common species are likely to belong to a manageable list of known species, enabling targeted efforts to understand their ecology. Although they do not detract from the importance of rare species, our results open new opportunities to understand the world’s most diverse forests, including modelling their response to environmental change, by focusing on the common species that constitute the majority of their trees.
... Dari 52 spesies yang berhasil diidentifikasi spesies yang paling banyak ditemukan adalah Livistona australis sebanyak 20 individu. Menurut Slik et al (2015) iklim tropis atau subtropis yang hangat dan lembab adalah kondisi lingkungan yang mendukung pertumbuhan pohon Livistoma australis. Pohon ini umumnya ditemukan di daerah dengan curah hujan yang cukup tinggi di antaranya pada wilayah dengan curah hujan tahunan antara 1.000 hingga 3.000 mm. ...
ABSTRAK
Keanekaragaman vegetasi pohon yang tinggi memiliki peran penting untuk ketersediaan sumber daya air. Proses hidrologis yang berarti hutan merupakan gudang penyimpanan air dan tempat penyerapan air hujan maupun embun yang akhirnya akan mengalir ke sungai-sungai di tengah hutan yang memiliki mata air, proses ini berlangsung secara teratur, selain itu vegetasi pohon yang membentuk hutan berperan melindungi tanah dari kekuatan erosi, serta melestarikan siklus unsur hara didalamnya. Dengan adanya DAS yang merupakan kesatuan ruang yang terdiri atas unsur abiotik yaitu tanah, air, dan udara, biotik yaitu vegetasi, binatang, dan organisme hidup lainnya, dan kegiatan manusia yang saling berinteraksi dan saling ketergantungan satu sama lain, sehingga merupakan satu kesatuan ekosistem.Vegetasi adalah kumpulan dari beberapa jenis tumbuhan yang tumbuh bersama-sama pada satu tempat dimana antara individu individu penyusunnya terdapat interaksi yang erat, baik diantara tumbuh-tumbuhan maupun dengan hewan-hewan yang hidup dalam vegetasi dan lingkungan tersebut. Dengan kata lain, vegetasi tidak hanya kumpulan dari individu-individu tumbuhan melainkan membentuk suatu kesatuan di mana individu-individunya saling tergantung satu sama lain, yang disebut sebagai suatu komunitas tumbuh-tumbuhan. Hasil pengukuran tanah di lokasi pengamatan menunjukkan suhu rata-rata sebesar 29,38°C dan kandungan pH tanah sebesar 7,318 yang termasuk dalam kondisi yang lembab. Hal ini dapat mempengaruhi pertumbuhan tanaman di sekitarnya, termasuk ketersediaan unsur hara. Keasaman pH tanah dapat mempengaruhi ketersediaan unsur hara yang terdapat dalam tanah tersebut (Sunarko, 2009). Tanah yang bersifat asam dapat mempengaruhi perkembangan yang baik dalam pertumbuhan generatif dan vegetatif tanaman.. Kondisi ini cocok untuk kelangsungan hidup berbagai jenis pohon yang ditemukan pada hasil penelitian ini terutama Livistona australis yang merupakan spesies terbanyak di semua stasiun. Pola penyebaran pohon di kawasan hutan Pantai Bama, berdasarkan nilai indeks dominan masing-masing spesies dan nilai indeks dominan rata-rata, adalah mengelompok (ID < 1).
kata kunci : vegetasi, pohon, lingkungan
... Tropical forests harbour many forest species with high economic value (Parmentier et al., 2007;Schroeder et al., 2010;Slik et al., 2015). However, anthropogenic activities including agriculture and extractive activities have been responsible for the degradation of these ecosystems (Ghazoul and Sheil, 2010;Maystadt et al., 2020). ...
... This is because tropical forests host a huge number of biodiversity compared to other realms (Gibson et al., 2011). For example, for the group of trees, there are 40,000-53,000 species estimated to occur in tropical forests (Slik et al., 2015). Beside the impacts on biodiversity, the loss of vegetation due to open-cast mining in tropical forest also removes the aboveground biomass, which is rich in organic carbon. ...
Open-cast mining in tropical forests causes negative impacts on biodiversity and carbon storage. Postmining reclamation is therefore imposed to recover the vegetation despite the lack of understanding which indicators can be used to monitor the progress ofsuccession. This study proposes an integrated framework to assess the trajectory of vegetation succession in coal mining site in East Kalimantan, Borneo. We combine the indicators of floristic diversity of naturally growing terrestrial and epiphytic plants, survival and growth of enrichment planting of native plants, above-ground carbon stock of pioneer trees, and the measurements on micro-climate and soil conditions. We compare some indicators across the 9-year-old and 17-year-old reclaimed sites and the premining sites. The results showed that naturally growing vegetation at the reclaimed sites was at the early to midsuccession stages, with biodiversity indicators much lower than those at the premining areas, implying the necessity of native species planting. During a six-month monitoring, the enrichment planting of native species had high rates of survival and growth. Surprisingly, the above-ground carbon at the two reclamation sites were higher, up to six times larger, than that at the premining sites. While the micro-climates had been improved, the soils in the reclaimed sites were still in poor conditions. Our findings suggest that using single parameter to monitor the trajectory of vegetation succession in postmining reclamation can be biased, and integrating several monitoring measures would provide a much better assessment.
... Additionally, the lower temperatures African forests tend to experience-as many are situated at slightly higher altitude than forests in Amazonia-could result in limited species tolerace of high temperatures. African forests are also much less species rich than forests in Amazonia and Asia (2,24), with a relative lack of species in high-temperature African forests (25), and this lower diversity could conceivably drive lower resistance to climate anomalies (26). ...
Significance
The responses of tropical forests to heat and drought are critical uncertainties in predicting the future impacts of climate change. The 2015–2016 El Niño Southern Oscillation (ENSO) resulted in unprecedented heat and low precipitation across the tropics, including in the very poorly studied African tropical forest region. We assess African forest ENSO responses using on-the-ground measurements. Across 100 long-term plots, record high temperatures did not significantly reduce carbon gains from tree growth or significantly increase carbon losses from tree mortality. Overall, despite the climate anomaly, forests continued to gain live biomass over the ENSO period. Our analyses, while limited to African tropical forests, suggest that they may be more resistant to climate extremes than Amazonian and Asian forests.
... All rights reserved worldwide. Until recently, most plant genomics research had been secluded to the industrialized world, although tropical Africa alone housed about 50 times more native plant species than countries in the temperate zone (Slik et al., 2015). Plant genomics research is currently gaining ground in Africa, and the continent is poised to become a hub of plant genomic research. ...
Plants are the world’s most consumed goods and they possess high economic and health values. In most countries in Africa, the supply and quality of food will rise to meet the growing population's increasing demand. Genomics and other tools of biotechnology offer the opportunity to improve on subsistence crops and medicinal herbs in the continent. Significant advancement has been made in plant genomics which has enhanced our knowledge of the molecular processes in both plant quality and yield. The sequencing of complex genomes of African plant species, facilitated by the continuously evolving Next Generation sequencing technologies and advanced bioinformatics approaches, have provided new opportunities for crop improvement. This review summarizes the achievements of genome sequencing projects of endemic African plants in the last two decades. We also present perspectives and challenges for future plant genomic studies that will accelerate important plant breeding programs for African communities. These challenges include lack of basic facilities, lack of skills for genomics studies design, sequencing, and bioinformatics analysis. However, it is imperative to state that African countries have become key players in the plant genome revolution and genome derived‐biotechnology. Therefore, African governments should invest in public plant genomics research and applications, establish bioinformatics platforms and training, and stimulate University and Industry partnership to fully deploy plant genomics, particularly to agriculture and medicine.
... Furthermore, investment in adequate maintenance of biodiversity collections would help prevent irreplaceable loss of preserved specimens and associated data (Escobar, 2018). However, declines in the number of botanists and reluctance to publish (by high-impact journals) and fund botanical work are starting to limit our ability to examine new or understudied taxa (Crisci et al., 2020), despite many tree species still awaiting description (Cheek et al., 2020;Slik et al., 2015). ...
Aims
Trees dominate the biomass in many ecosystems and are essential for ecosystem functioning and human well‐being. They are also one of the best studied functional groups of plants, with vast amounts of biodiversity data available in scattered sources. We here aim to illustrate that an efficient integration of this data could produce a more holistic understanding of vegetation.
Methods
To assess the extent of potential data integration, we use key databases of plant biodiversity to 1) obtain a list of tree species and their distributions, 2) identify coverage and gaps of different aspects of tree biodiversity data, and 3) discuss large‐scale patterns of tree biodiversity in relation to vegetation.
Results
Our global list of trees included 58,044 species. Taxonomic coverage varies in three key databases, with data on the distribution, functional traits, and molecular sequences for about 84%, 45% and 44% of all tree species, which is > 10% greater than for plants overall. For 28% of all tree species, data are available in all three databases. However, less data are digitally accessible about the demography, ecological interactions, and socio‐economic role of tree species. Integrating and imputing existing tree biodiversity data, mobilization of non‐digitized resources and targeted data collection, especially in tropical countries, could help closing some of the remaining data gaps.
Conclusions
Due to their key ecosystem roles and having large amounts of accessible data, trees are a good model group for understanding vegetation patterns. Indeed, tree biodiversity data are already beginning to elucidate the community dynamics, functional diversity, evolutionary history and ecological interactions of vegetation, with great potential for future applications. An interoperable and openly accessible framework linking various databases would greatly benefit future macroecological studies, and should be linked to a platform that makes information readily accessible to end users in biodiversity conservation and management.
... Virtually all other studies at standardized spatial scales larger than 0.1 ha for trees ≥10 cm in dbh confirm the relative paucity of species in Africa's tropical forests ( fig. 1; Parmentier et al. 2007;Kissling et al. 2012;Ricklefs and Renner 2012;Linder 2014;Couvreur 2015;Slik et al. 2015). Thus, the disparity in richness between Africa's tropical forests and those on other continents is real, and although some sampled areas in Africa are as rich as in South America and Southeast Asia, none are even nearly equal to the richest forests of Ecuador and Malaysia. ...
... The occurrences were collated from (i) 212 dried herbarium collections examined at BR, BRLU, LBV, MA, MO, FHI, K, L, P, U, WAG and YA herbaria (acronyms following the Index Herbariorum of Thiers) and the Global Plants database (http://plants.jstor.org); (ii) 1352 ebony trees cut by Crelicam SARL Ebony mill in Cameroon from 2014 to 2018, 157 of which were associated with a dried leaf sample examined during this study; (iii) 248 unique occurrences of D. crassiflora recorded in inventories conducted post-2005 in logging concessions in Gabon collected by Sylvafrica; (iv) 16 collections of dried plant samples kept at the Université Libre de Bruxelles extracted from the RAINBIO dataset (Dauby et al. 2016); 155 unique occurrences of the species in inventory data from old-growth forests collated by Gilles Dauby and Ferry Slick (Slik et al., 2015). An earlier version of this dataset was published in Schatz et al. (2019). ...
The Central African forest ebony, Diospyros crassiflora Hiern, is a small tree native to the moist forests of the Congo Basin. Its appealing black heartwood was one of the first products to be exported from the Gulf of Guinea in the 17th century and is today one of the main sources of ebony globally. Like for other ebony species, its commercial exploitation raises serious questions about the long-term sustainability of its trade and the viability of its populations, but the dots are yet to be joined. An examination of the interface between biology, trade, and ecology is crucial to identify the interrelated factors that could influence the potential success of its conservation. This paper reviews scientific and grey literature, forest inventories, herbarium and trade data to provide a critical assessment of the main threats to D. crassiflora populations and gaps in the current state of knowledge. It is shown here that the species is widespread but never abundant. In the longer term the species is threatened by forest conversion to agriculture and widespread hunting of large mammals on which the species rely for seed dispersal. It is currently selectively logged principally to make musical instruments and for the hongmu Chinese market, for which only one alternative black wood, the near-threatened Dalbergia melanoxylon Guill. et Perr., is commercially available. Trade statistics suggest that exports from source countries where the species is cut under the forest concession system are relatively low compared to countries like Cameroon which has seen a recent increase in exports, and where ebony is exploited without forest management plans. Logging remains a concern where the exploitation and trade of D. crassiflora are managed in response to demand rather than informed by current stock levels, growth rate and the particular reproductive biology of this species. The recent successes of private sector initiatives to ensure the long-term supply of ebony in Cameroon are promising, but would require long-term and large-scale commitments involving direct and indirect stakeholders to develop programs for the plantation and policies for the sustainable management of the species.
