Worldmaps of plant diversity

Worldmaps of Plant diversity

Barthlott, W., Hostert, A., Kier, G., Küper, W., Kreft, H., Mutke, J., Rafiqpoor, M.D. & H. Sommer (2007): Geographic patterns of vascular plant diversity at continental to global scales. Erdkunde 61: 305-315. pdf at www.erdkunde.uni-bonn.de

Global Plant Diversity Map as PDF

Documenting and understanding patterns of biodiversity is a central issue in biogeography and macroecology. Knowledge about the distribution of biodiversity is also a central prerequisite for its sustainable use and conservation. Due to a greater availability of distribution data, methodological advances, and software tools, important progress has been made during the last decade to map broad-scale geographic gradients of plant species richness and endemism at continental to global scales. In this paper, we provide an overview about recent advances made in this field. We present studies that analyze globalscale diversity patterns of gymnosperms and all vascular plants. Exemplarily for the model continent Africa, we show how biogeographic data can be used to develop broad-scale conservation strategies.

Kier, G., Kreft, H., Lee, T.M., Jetz, W., Ibisch, P.I., Nowicki, C., Mutke, J. & Barthlott, W. (2009): A global assessment of endemism and species richness across island and mainland regions. PNAS 2009 106: 9322-9327, doi:10.1073/pnas.0810306106

http://www.pnas.org/cgi/content/short/0810306106

 Endemism and species richness are highly relevant to the global prioritization of conservation efforts in which oceanic islands have remained relatively neglected. When compared to mainland areas, oceanic islands in general are known for their high percentage of endemic species but only moderate levels of species richness, prompting the question of their relative conservation value. Here we quantify geographic patterns of endemism-scaled richness ('endemism richness') of vascular plants across 90 terrestrial biogeographic regions, including islands, worldwide and evaluate their congruence with terrestrial vertebrates. Endemism richness of plants and vertebrates is strongly related, and values on islands exceed those of mainland regions by a factor of 9.5 and 8.1 for plants and vertebrates, respectively. Comparisons of different measures of past and future human impact and land cover change further reveal marked differences between mainland and island regions. While island and mainland regions suffered equally from past habitat loss, we find the human impact index, a measure of current threat, to be significantly higher on islands. Projected land-cover changes for the year 2100 indicate that land-use driven changes on islands might strongly increase in the future. Given their conservation risks, smaller land areas, and high levels of endemism richness, islands may offer particularly high returns for species conservation efforts and therefore warrant a high priority in global biodiversity conservation in this century.

Geffert, J. L., J.-P. Frahm, W. Barthlott, & J. Mutke (2013) Global moss diversity: spatial and taxonomic patterns of species richness. Journal of Bryology 35(1), 1-11.

http://www.ingentaconnect.com/content/maney/jbr/2013/00000035/00000001/art00001

We have analysed the global patterns of moss species diversity based on a dataset created from checklists, online databases, and herbarium records. We collected more than 100 000 distribution records for over 400 different geographical units and standardized species taxonomy using the TROPICOS database of the Missouri Botanical Garden. Maps of overall moss species richness, as well as individual maps for taxonomic orders of mosses, are provided. Based on our dataset, we did not find a general latitudinal gradient of increasing moss diversity with decreasing latitude. Several areas of temperate broadleaf forests, boreal forests, and tundra show relatively high species richness that is comparable to tropical regions. Centres of moss diversity include the northern Andes, Southeast Asia, Mexico, and Japan, as well as the Himalayan region, Madagascar, the East African Highlands, central Europe, Scandinavia, and British Columbia. Our dataset presents the first collection of moss species inventories with global coverage. It contributes to documentation and understanding of global biogeographic patterns in mosses, helps to identify gaps in floristic knowledge, and could prove to be a valuable resource to aid taxonomic and systematic revisions or assessments of species and genera, by quickly and easily supplying an overview of the geographic distribution of a given taxon.

Barthlott, W., Mutke, J., Rafiqpoor, M. D., Kier, G. and Kreft, H. (2005): Global centres of vascular plant diversity. Nova Acta Leopoldina 92, 61-83. PDF

Global Plant Diversity Map as PDF

The diversity of vascular plants is very unevenly distributed across the globe. The five centres that reach species richness of more than 5,000 spp./10,000 km2 (Costa Rica-Chocó, Atlantic Brazil, Tropical Eastern Andes, Northern Borneo, New Guinea) cover only 0.2 % of the terrestrial surface. On the other hand approximately 18,500 spp. are endemic to these centres which represent 6.2 % of all vascular plant species. A world map of vascular plant richness is presented based on an extensively expanded data base (more than 3,300 species richness figures for different regions of the world) and a refined methodology. Most of the global centres are located in mountainous regions within the humid tropics, where suitable climatic conditions and high levels of geodiversity, i.e., the diversity of abiotic conditions, coincide. A complete review of most prominent climatic, geologic, and floristic features of the 20 centres of phytodiversity with more than 3,000 spp. / 10,000 km2 is presented.

Mutke, J. & Barthlott, W. (2005). Patterns of vascular plant diversity at continental to global scales. Biologiske Skrifter 55, 521-531. PDF

The studies presented in this paper analyse diversity patterns of land plants (mosses, ferns, gymnosperms, and angiosperms) at continental to global scales. A revised version of our earlier world map of vascular plant species richness and the first maps of species richness of mosses and gymnosperms on a global scale are presented. Diversity patterns of vascular plants are correlated with different measures of geodiversity (the diversity of the abiotic environment). Global centres of vascular plant diversity coincide with highly structured, geodiverse areas in the tropics and subtropics. These are the Chocó-Costa Rica region, the tropical eastern Andes and the north western Amazonia, the eastern Brazil, the northern Borneo, and New Guinea, as well as the South African Cape region, southern Mexico, East Himalaya, western Sumatra, Malaysia, and eastern Madagascar. Constraints imposed by the physical environment, such as the length of the thermal vegetation period or water availability, shape large scale trends of biodiversity. However, important centres of species richness and endemism can only be explained when taking into account the history of the floras. The main diversity centres in SE Asia are the same for gymnosperms as for all other vascular plants, but in other parts of the tropics and subtropics there is low gymnosperm diversity. The exceptions to this pattern are Mexico and California, which have almost as many species of gymnosperms as SE Asia. The increase in the number of species and genera published during the last 250 years is documented, based on data from the Index Kewensis. The first continental maps of Cactaceae diversity at species and genus level are used to show how choice of the taxonomic level affects the analysis and its implications for priority setting in biodiversity conservation. In this context, global biodiversity hotspots are discussed and an alternative world map of hotspots is proposed.

Kier, G., Mutke, J., Dinerstein, E., Ricketts, T. H., Küper, W., Kreft, H. and Barthlott, W. (2005): Global patterns of plant diversity and floristic knowledge. Journal of Biogeography 32, 1107-1116.

http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2699.2005.01272.x/abstract

We present the first global map of vascular plant species richness by ecoregion and compare these results with the published literature on global priorities for plant conservation. In so doing, we assess the state of floristic knowledge across ecoregions as described in floras, checklists, and other published documents and pinpoint geographical gaps in our understanding of the global vascular plant flora. Finally, we explore the relationships between plant species richness by ecoregion and our knowledge of the flora, and between plant richness and the human footprint - a spatially explicit measure of the loss and degradation of natural habitats and ecosystems as a result of human activities.

Location: Global.

Methods: Richness estimates for the 867 terrestrial ecoregions of the world were derived from published richness data of c. 1800 geographical units. We applied one of four methods to assess richness, depending on data quality. These included collation and interpretation of published data, use of species-area curves to extrapolate richness, use of taxon-based data, and estimates derived from other ecoregions within the same biome.

Results: The highest estimate of plant species richness is in the Borneo lowlands ecoregion (10,000 species) followed by nine ecoregions located in Central and South America with ‡ 8000 species; all are found within the Tropical and Subtropical Moist Broadleaf Forests biome. Among the 51 ecoregions with ‡ 5000 species, only five are located in temperate regions. For 43% of the 867 ecoregions, data quality was considered good or moderate. Among biomes, adequate data are especially lacking for flooded grasslands and flooded savannas. We found a significant correlation between species richness and data quality for only a few biomes, and, in all of these cases, our results indicated that species-rich ecoregions are better studied than those poor in vascular plants. Similarly, only in a few biomes did we find significant correlations between species richness and the human footprint, all of which were positive.

Main conclusions: The work presented here sets the stage for comparisons of degree of concordance of plant species richness with plant endemism and vertebrate species richness: important analyses for a comprehensive global biodiversity strategy. We suggest: (1) that current global plant conservation strategies be reviewed to check if they cover the most outstanding examples of regions from each of the world's major biomes, even if these examples are speciespoor compared with other biomes; (2) that flooded grasslands and flooded savannas should become a global priority in collecting and compiling richness data for vascular plants; and (3) that future studies which rely upon species-area calculations do not use a uniform parameter value but instead use values derived separately for subregions.

Konrat, M. V., M. Renner, L. Söderström, A. Hagborg, & J. Mutke. (2008). Early Land Plants Today: Liverwort Species Diversity and the Relationship with Higher Taxonomy and Higher Plants. Fieldiana Botany 47(1): 91–104.

http://www.bioone.org/doi/abs/10.3158/0015-0746-47.1.91

Kreft, H., Jetz, W. Mutke, J. & Barthlott, W. (2010): Contrasting environmental and regional effects on global pteridophyte and seed plant diversity. Ecography 33: 408-419. doi: 10.1111/j.1600-0587.2010.06434.x

http://onlinelibrary.wiley.com/doi/10.1111/j.1600-0587.2010.06434.x/abstract

Pteridophytes (ferns and fern-allies) represent the second-largest group of vascular plants, but their global biogeography remains poorly studied. Given their functional biology, pteridophytes are expected to show a more pronounced relation to water availability and a higher dispersal ability compared to seed plants. We test these assertions and document the global pattern of pteridophyte richness across 195 mainland and 106 island regions. Using non-spatial and spatial simple and multiple regression models, we analyze geographic trends in pteridophyte and seed plant richness as well as pteridophyte proportions in relation to environmental and regional variables. We find that pteridophyte and seed plant richness are geographically strongly correlated (all floras: r=0.68, mainland: r=0.82, island floras: r=0.77), but that the proportions of pteridophytes in vascular plant floras vary considerably (0–70%). Islands (mean=15.3%) have significantly higher proportions of pteridophytes than mainland regions (mean=3.6%). While the relative proportions of pteridophytes on islands show a positive relationship with geographic isolation, proportions in mainland floras increase most strongly along gradients of water availability. Pteridophyte richness peaks in humid tropical mountainous regions and is lowest in deserts, arctic regions, and on remote oceanic islands. Regions with Mediterranean climate, outstanding extra-tropical centres of seed plant richness, are comparatively poor in pteridophytes. Overall, water-energy variables and topographical complexity are core predictors of both mainland pteridophyte and seed plant richness. Significant residual richness across biogeographic regions points to an important role of idiosyncratic regional effects. Although the same variables emerge as core predictors of pteridophyte and seed plant richness, water availability is clearly a much stronger constraint of pteridophyte richness. We discuss the different limitations of gametophytes and sporophytes that might have limited the ability of pteridophytes to extensively diversify under harsh environmental conditions. Our results point to an important role of taxon-specific functional traits in defining global richness gradients.

Barthlott, W., Biedinger, N., Braun, G., Feig, F., Kier, G. and Mutke, J. (1999): Terminological and methodological aspects of the mapping and analysis of global biodiversity. Acta Botanica Fennica 162, 103-110.

A world map of the potential species diversity of terrestrial vascular plants based on thee valuation of approximately 1400 records from literature is presented. The number of species for the areas covered has been calculated for a standard area of 10000 km2 by a benchmark formula. Ten diversity zones in categories within the spectrum of less than 100 species and more than 5000 species per 10000 km2 have been considered and mapped by ten colour indicators. Furthermore, some different approaches to the largescale mapping of biodiversity are reviewed. In the context of the elaboration of the map, it became clear that certain terminological and methodological issues need to be clarified. Based on the existing literature, a terminology for the classification of plants according to the mode and time of their first occurrence in the study area, and for the respective diversities, is introduced. It is particularly important to distinguish between the autodiversity, i.e. the diversity of indigenous plants (autophytes), and the allodiversity, i.e. the diversity of plants introduced by man (allophytes). In addition, for other purposes it is more important to distinguish between the eudiversity, i.e. the diversity of autophytes and plants introduced with the former continuous migration of man (archaeophytes), and the neodiversity, i.e. the diversity of plants dispersed by man over large distances, usually resulting in distribution gaps (neophytes). Neodiversity is increased tremendously by neoterodiversity, i.e. the diversity of plants dispersed in the context of motorised mass transportation since the end of the last century (neoterophytes, "invaders").

Barthlott, W., Lauer, W. and Placke, A. (1996): Global distribution of species diversity in vascular plants: towards a world map of phytodiversity. Erdkunde 50, 317-328.

An annotated, coloured world map of the potential species diversity of vascular plants to serve as a basis for a future world map of biodiversity is presented. Despite the abundance of maps depicting vegetation and distribution which have already been published, a pictorial representation of this kind is lacking, apart from the early map by Malyshev (1975). This is all the more surprising considering that biodiversity and the distribution of genetic resources today are among the major focal points in scientific and political discussions on an international scale.

Our knowledge of the diversity and distribution of higher plants is extensive in comparison to our cognizance of other larger groups of organisms (e.g. arthropods). The evaluation of data from approximately 1400 floras, floristic studies, biogeographical essays and vegetation studies, regional to continental in scope, provides the mainstay for our map. The species numbers of the areas covered (predominantly political units) is calculated for a standard area of 10000 sq. km. by a benchmark formula. Ten diversity zones in categories within the spectrum of less than 100 species and more than 5000 species per 10000 sq. km. have been considered and mapped by ten colour indicators. Because political, and not natural, units constituted the data utilized, zonation boundaries of those areas with equal taxa density (isotaxas) are inferred on the basis of climatic and other data.

This world map diverges in significant details from hitherto acknowledged concepts of the distribution of diversity (e.g. the Cameroon-Gabon Centre is identified as a diversity maximum for Africa for the first time). We recognize six global species maxima: 1. Chocó-Costa Rica Centre, 2. Tropical Eastern Andes Centre, 3. Atlantic Brazil Centre , 4. Eastern Himalaya-Yunnan Centre, 5. Northern Borneo Centre, 6. New Guinea Centre.

The results are elucidated by explanatory comments and critical discussion. Inevitably, a number of terminological issues must be clarified (e.g. isotaxas - isoporia, diversity maxima, diversity centres, criteria governing the quality of diversity, landscape diversity - geodiversity - ecodiversity, etc.). As is to be expected, the biodiversity of an area does not depend solely on its history (climatic and floristic history, palaeogeography and evolutionary availability of genetic diversity) or its position (degree of isolation and zonobiom), but also on the whole variety of its abiotic parameters (geodiversity). In this context, a connection becomes apparent between tropical diversity maxima and oceanic surface temperatures of more than 27°C.

With reference to and in the context of the well documented interdependent ecosystem of primary producers (vascular plants) with consumers and decomposers, we suppose that the map reflects quite accurately the global distribution of terrestrial biodiversity in its entirety.