Patterns, determinants and models of woody plant diversity in China

SUMMARYRecent evidence has shown that most tropical species are declining as a result of global change. Under this scenario, the prevalence of tolerant species to disturbances has driven many biological communities towards biotic homogenization (BH). However, the mechanisms that drive communities towards BH are not yet thoroughly understood. We tested effects of recurring wildfires on woody species richness and composition in six seasonally flooded Amazonian forests and whether these fires reduce species composition (i.e., taxonomic homogenization) over short periods of time. Our results show that these forests are undergoing taxonomic homogenization in response to recurring fire events. Species richness decreased as a result of local extinctions and floristic similarity increased among forest communities. Fire was selecting tolerant (‘winner’) species and eliminating the more sensitive (‘loser’) species. BH leads to biodiversity erosion, which can deeply alter ecosystem processes such as productivity, nutrient cycling and decomposition, resulting in important consequences for conservation.

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Low predictive power of mid-domain effect to explain geographic species richness patterns in Palearctic songbirds

Contributions to Zoology ◽

10.1163/18759866-07603005 ◽

2007 ◽

Vol 76 (3) ◽

pp. 197-204 ◽

Cited By ~ 1

Author(s):

M. Aliabadian ◽

C. S. Roselaar ◽

R. Sluys ◽

V. Nijman

Keyword(s):

Species Richness ◽

Predictive Power ◽

Explanatory Power ◽

Null Model ◽

Species Range ◽

Geometric Constraints ◽

Diversity Patterns ◽

Distribution Maps ◽

Biogeographic Patterns ◽

Richness Patterns

In the study of diversity patterns, the Mid-domain effect (MDE), which explains gradients in diversity solely on the basis of geometric constraints, has emerged as a null-model against which other hypotheses can be tested. The effectiveness, measured by its predictive power, of these MDE models appears to depend on the size of the study area and the range-sizes of the taxa considered. Here we test the predictive power of MDE on the species richness patterns of birds and assess its effectiveness for a variety of species range sizes. We digitised distribution maps of 889 species of songbird endemic to the Palearctic, and analysed the emergent biogeographic patterns with WORLDMAP software. MDE had a predictive power of 20% when all songbirds were included. Major hotspots were located south of the area where MDE predicted the highest species-richness, and some of the observed coldspots were in the centre of the Palearctic, contradicting the predictions of the MDE. MDE had little explanatory power (3-19%) for all but the largest range sizes, whereas MDE performed equal or better for the large-ranged species (20-34%) compared to the overall model. Overall MDE did not accurate explain species-richness patterns in Palearctic songbirds. Subsets of larger-range species did not always have a larger predictive power than smaller-range species or the overall model. Despite their low predictive power, MDE models can have a role to play in explaining biogeographic patterns but other variables need to be included in the model as well.

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Online appendix 1:Exploring an extensive dataset to establish woody vegetation cover and composition in Kruger National Park for the late 1980s

Koedoe ◽

10.4102/koedoe.v56i1.1200-1 ◽

2014 ◽

Vol 56 (1) ◽

Author(s):

Gregory A. Kiker ◽

Rheinhardt Scholtz ◽

Izak P.J. Smit ◽

Freek J. Venter

Keyword(s):

Species Richness ◽

Vegetation Cover ◽

National Park ◽

Large Scale ◽

Plant Cover ◽

Canopy Cover ◽

Woody Species ◽

Kruger National Park ◽

Tree Cover ◽

Woody Vegetation

Woody plant cover and species composition play an important role in defining the type and function of savanna ecosystems. Approximately 2000 sites in the Kruger National Park (KNP) were surveyed by F.J. Venter over a period from 1985 to 1989, recording vegetation, soil and topological characteristics. At each of these sites (approximately 20 m × 20 m each), woody vegetation cover and species were recorded using a rapid, Braun-Blanquet classification for three height classes: shrub (0.75 m – 2.50 m), brush (2.50 m – 5.50 m) and tree (> 5.50 m). The objective of this study was to re-analyse the vegetation component of the field data, with a specific focus to provide a spatially explicit, height-differentiated, benchmark dataset in terms of species occurrence, species richness and structural canopy cover. Overall, 145 different woody species were recorded in the dataset out of the 458 species documented to occur in the park. The dataset describes a woody layer dominated by a relatively small number of widely occurring species, as 24 of the most common woody species accounted for all woody species found on over 80% of all sites. The less common woody species (101) were each recorded on 20 sites or less. Species richness varied from 12 to 1 species per site. Structural canopy cover averaged 9.34%, 8.16% and 2.89% for shrub, brush and tree cover, respectively. The dataset provides a useful benchmark for woody species distribution in KNP and can be used to explore woody species and height class distributions, as well as comparison with more recent or future woody vegetation surveys.Conservation implications: The results provided evidence that large-scale, woody vegetation surveys conducted along roads offer useful ecosystem level information. However, such an approach fails to pick up less common species. The data presented here provided a useful snapshot of KNP woody vegetation structure and composition and could provide excellent opportunities for spatio-temporal comparisons.

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Water availability, bedrock, disturbance by herbivores, and climate determine plant diversity in South-African savanna

Scientific Reports ◽

10.1038/s41598-021-02870-3 ◽

2022 ◽

Vol 12 (1) ◽

Author(s):

Martin Hejda ◽

Jan Čuda ◽

Klára Pyšková ◽

Guin Zambatis ◽

Llewellyn C. Foxcroft ◽

...

Keyword(s):

Species Richness ◽

South African ◽

Plant Diversity ◽

Water Availability ◽

Large Scale ◽

Woody Species ◽

Plant Species Richness ◽

African Savanna ◽

Shrub Species ◽

Large Herbivores

AbstractTo identify factors that drive plant species richness in South-African savanna and explore their relative importance, we sampled plant communities across habitats differing in water availability, disturbance, and bedrock, using the Kruger National Park as a model system. We made plant inventories in 60 plots of 50 × 50 m, located in three distinct habitats: (i) at perennial rivers, (ii) at seasonal rivers with water available only during the rainy season, and (iii) on crests, at least ~ 5 km away from any water source. We predicted that large herbivores would utilise seasonal rivers’ habitats less intensely than those along perennial rivers where water is available throughout the year, including dry periods. Plots on granite harboured more herbaceous and shrub species than plots on basalt. The dry crests were poorer in herb species than both seasonal and perennial rivers. Seasonal rivers harboured the highest numbers of shrub species, in accordance with the prediction of the highest species richness at relatively low levels of disturbance and low stress from the lack of water. The crests, exposed to relatively low pressure from grazing but stressed by the lack of water, are important from the conservation perspective because they harbour typical, sometimes rare savanna species, and so are seasonal rivers whose shrub richness is stimulated and maintained by the combination of moderate disturbance imposed by herbivores and position in the middle of the water availability gradient. To capture the complexity of determinants of species richness in KNP, we complemented the analysis of the above local factors by exploring large-scale factors related to climate, vegetation productivity, the character of dominant vegetation, and landscape features. The strongest factor was temperature; areas with the highest temperatures reveal lower species richness. Our results also suggest that Colophospermum mopane, a dominant woody species in the north of KNP is not the ultimate cause of the lower plant diversity in this part of the park.

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Species diversity and endemism: testing the mid-domain effect on species richness patterns of songbirds in the Palearctic Region

Contributions to Zoology ◽

10.1163/18759866-07702006 ◽

2008 ◽

Vol 77 (2) ◽

pp. 99-108 ◽

Cited By ~ 3

Author(s):

Mansour Aliabadian ◽

Ronald Sluys ◽

Cees S. Roselaar ◽

Vincent Nijman

Keyword(s):

Species Richness ◽

Explanatory Power ◽

Empirical Support ◽

Grid Cell ◽

Distribution Patterns ◽

Distribution Maps ◽

Biogeographic Patterns ◽

Palearctic Region ◽

Richness Pattern ◽

Constraint Model

Explanation of the spatial distribution patterns in species richness, and especially those of small-ranged species (endemics), bears relevance for studies on evolution and speciation, as well as for conservation management. We test a geometric constraint model, the mid-domain effect (MDE), as a possible explanation for spatial patterns of species richness in Palearctic songbirds (Passeriformes), with an emphasis on the patterns of small-ranged species. We calculated species richness based on digitised distribution maps of phylogenetic species of songbirds endemic to the Palearctic region. Data were plotted and analyzed over a one degree equal area map of the Palearctic Region, with a grid cell area of 4062 km². The emergent biogeographic patterns were analysed with WORLDMAP software. Comparison of the observed richness pattern among 2401 phylogenetic taxa of songbirds in the Palearctic Region with the predictions of a fully stochastic bi-dimensional MDE model revealed that this model has limited empirical support for overall species richness of Palearctic songbirds. Major hotspots were located south of the area where MDE predicted the highest species- richness, while some of the observed coldspots were in the centre of the Palearctic Region. Although small-ranged species are often found in areas with the highest species richness, MDE models have a very restricted explanatory power for the observed species-richness pattern in small-ranged species. Regions with a high number of small-ranged species (endemism hotspots) may contain a unique set of environmental conditions, unrelated to the shape or size of the domain, allowing a multitude of species to co-exist.

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MAT drives the variation in maximum potential species richness and frost organizes the residual variation

10.1101/836338 ◽

2019 ◽

Author(s):

Ricardo A. Segovia

Keyword(s):

Species Richness ◽

Upper Bound ◽

Large Scale ◽

Explanatory Power ◽

Mean Annual Temperature ◽

Natural Logarithm ◽

Residual Variation ◽

Limited Support ◽

Main Driver ◽

The Relationship

AbstractThe kinetic hypothesis of biodiversity proposes that Mean Annual Temperature (MAT) is the main driver of variation in species richness, given its exponential effect on rates of energy flux and thus, potentially, on rates of biological interaction and diversification. However, limited support for this hypothesis has been found to date. We tested the fit of this model on the variation of tree species richness across the Americas. We found that the kinetic hypothesis accurately predicts the upper bound of the relationship between the inverse of temperature (1,000/kK) and the natural logarithm of species richness. In addition, we found that the number of frost days organizes a substantial portion of the residual variation. Historically, attempts to explain large-scale variation of species richness has focused on gradients of independent variables, but explanatory power has been limited. More than a gradient, the fit of the upper bound of the exponential Boltzmann temperature model of variation of observed species richness can be seen as an upper limit on the species richness per unit of MAT. Likewise, the distribution of the residuals of the upper bound model in function of the number of days with freezing temperatures, shows the importance of environmental thresholds, rather than gradients driving species richness variation.

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Intensification of Large-Scale Stretching of Atmospheric Pollutant Clouds due to Climate Change

Journal of the Atmospheric Sciences ◽

10.1175/jas-d-17-0133.1 ◽

2017 ◽

Vol 74 (12) ◽

pp. 4229-4240 ◽

Cited By ~ 4

Author(s):

Tímea Haszpra

Keyword(s):

Topological Entropy ◽

Large Scale ◽

Chaotic Systems ◽

Relative Vorticity ◽

Strongly Correlated ◽

Atmospheric Pollutant ◽

Absolute Value ◽

Exponential Stretching ◽

The Mean ◽

Climate Influences

Abstract The aim of the paper is to investigate the question of how a changing climate influences the spreading of pollutants on continental and global scales. For characterizing the spreading, a measure of chaotic systems, called topological entropy, is used. This quantity describes the exponential stretching of pollutant clouds and, therefore, is related to the predictability and the complexity of the structure of a pollutant cloud. For the dispersion simulations the ERA-Interim database is used from 1979 to 2015. The simulations demonstrate that during this period the mean topological entropy slightly increases: the length of an initially line-like pollutant cloud advected for 10 (30) days in the atmosphere becomes 20%–65% (200%–400%) longer by the 2010s than in the 1980s. The mean topological entropy is found to be strongly correlated with the mean of the absolute value of the relative vorticity and only weakly linked to the mean temperature.

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Spatial Pattern of Species Richness among Terrestrial Mammals in China

Diversity ◽

10.3390/d12030096 ◽

2020 ◽

Vol 12 (3) ◽

pp. 96

Author(s):

Yao Chi ◽

Jiechen Wang ◽

Changbai Xi ◽

Tianlu Qian ◽

Caiying Sheng

Keyword(s):

Species Richness ◽

Spatial Pattern ◽

Large Scale ◽

Negative Relationship ◽

Geographical Information ◽

Western China ◽

Strongly Correlated ◽

Terrestrial Mammals ◽

Richness Patterns ◽

Forested Ecosystems

We describe large-scale patterns of terrestrial mammal distribution in China by using geographical information system (GIS) spatial analysis. Mammal taxa, examined by species, family, and order, were binned into 10 km × 10 km grids to explore the relationship between their spatial distribution and geographical factors potentially affecting the same. The spatial pattern of species richness revealed four agglomerations: high richness in the south, low in north, and two low richness areas in eastern and western China. Species richness patterns in Carnivora was the most similar to overall terrestrial mammals’ richness; however, species richness in different orders exhibited distributions distinct from the overall pattern. We found a negative relationship between richness and latitude gradient. Species richness was most strongly correlated with forested ecosystems, and was found to be higher at an elevation of 2000~2200 m, with greater altitudinal variation indicative of higher species richness.

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Exploring an extensive dataset to establish woody vegetation cover and composition in Kruger National Park for the late 1980s

Koedoe ◽

10.4102/koedoe.v56i1.1200 ◽

2014 ◽

Vol 56 (1) ◽

Cited By ~ 5

Author(s):

Gregory A. Kiker ◽

Rheinhardt Scholtz ◽

Izak P.J. Smit ◽

Freek J. Venter

Keyword(s):

Species Richness ◽

Vegetation Cover ◽

National Park ◽

Large Scale ◽

Plant Cover ◽

Canopy Cover ◽

Woody Species ◽

Kruger National Park ◽

Tree Cover ◽

Woody Vegetation

Woody plant cover and species composition play an important role in defining the type and function of savanna ecosystems. Approximately 2000 sites in the Kruger National Park (KNP) were surveyed by F.J. Venter over a period from 1985 to 1989, recording vegetation, soil and topological characteristics. At each of these sites (approximately 20 m × 20 m each), woody vegetation cover and species were recorded using a rapid, Braun-Blanquet classification for three height classes: shrub (0.75 m – 2.50 m), brush (2.50 m – 5.50 m) and tree (> 5.50 m). The objective of this study was to re-analyse the vegetation component of the field data, with a specific focus to provide a spatially explicit, height-differentiated, benchmark dataset in terms of species occurrence, species richness and structural canopy cover. Overall, 145 different woody species were recorded in the dataset out of the 458 species documented to occur in the park. The dataset describes a woody layer dominated by a relatively small number of widely occurring species, as 24 of the most common woody species accounted for all woody species found on over 80% of all sites. The less common woody species (101) were each recorded on 20 sites or less. Species richness varied from 12 to 1 species per site. Structural canopy cover averaged 9.34%, 8.16% and 2.89% for shrub, brush and tree cover, respectively. The dataset provides a useful benchmark for woody species distribution in KNP and can be used to explore woody species and height class distributions, as well as comparison with more recent or future woody vegetation surveys.Conservation implications: The results provided evidence that large-scale, woody vegetation surveys conducted along roads offer useful ecosystem level information. However, such an approach fails to pick up less common species. The data presented here provided a useful snapshot of KNP woody vegetation structure and composition and could provide excellent opportunities for spatio-temporal comparisons.

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Riqueza total de especies de plantas vasculares en un bosque andino de la Cordillera central de Colombia

Revista de Biología Tropical ◽

10.15517/rbt.v66i1.27548 ◽

2017 ◽

Vol 66 (1) ◽

pp. 227

Author(s):

Heriberto David-Higuita ◽

Esteban Alvarez-Dávila

Keyword(s):

Species Richness ◽

Tropical Forests ◽

Woody Plants ◽

Vascular Plants ◽

Woody Species ◽

Plant Size ◽

Detailed Knowledge ◽

Relative Contribution ◽

Total Species Richness ◽

Total Species

Studies of plant diversity in tropical forests are usually restricted to trees or other groups of woody plants above a certain stem diameter. However, surveys that include all forms of live plants with no restrictions on their sizes, clearly indicate that non-woody plants are equally important. In this study, we reported the total species richness of vascular plants species (TSR) in one hectare plot in an Andean forest in Northwestern Colombia (6º 12' 48” N & 75º 29' 32” W). We evaluated the relative contribution of the different growth habits and the effect of the plant size, to TSR. We measured all individuals with diameter (D) ≥ 5 cm in the hectare and all the vascular plants of all sizes, including epiphytes, in a subsample of 0.25 ha. A total of 14 545 individuals distributed in 318 species, 72 families (considering Pteridophyta as one group) and 171 genera were registered. Most of the species showed a (D) < 10 cm (99.7%) and < 2.5 cm (94.4 %). The no-arboreal species (ground herbs, epiphytes and vines) represented 54.3 % of the total species reported in the plot, indicating that they are important in the structure, composition and species richness of this montane forest. Our results coincide with similar studies in other tropical forests. We concluded that to get a more detailed knowledge of the floristic diversity of a site, it is advisable to: 1) amplify the size range of the plants generally considered in the floristic inventories and 2) to include non-woody species. This information is crucial for making better decisions in local and global conservation efforts.

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