Jürgen Kluge

• Philipps University of Marburg

Tropical ferns are underrepresented in demographic studies, despite their ecological importance in forest ecosystems. This study investigates the mortality rates of terrestrial ferns along an elevational gradient (500–4000 m a.s.l.) in Ecuador, focusing on relationships with environmental variables, community characteristics, and plant size. Over t...

Mountains are the global centers of fern diversity and at the same time strongly affected by climate change, raising the question of how fern species and communities will respond to these changes. In the present review, which also includes our own unpublished data, we first outline the challenges of identifying distributional boundaries in ferns. W...

Questions Bryophytes attain their highest diversity in tropical mountain forests. Although distribution patterns have been described, little emphasis has been placed on comparing patterns among substrates (e.g., terrestrial, epiphytic). Understanding these patterns is important, because they determine not only the pool of genetic resources, but als...

Deforestation and forest fragmentation have serious negative consequences for biodiversity and species distribution, but many studies approach species distributions and speciation processes without taking in account the local history of human disturbances. Nevertheless, the complex recovery process after forest destruction is widely distributed aro...

Much attention has been directed to understandingspecies richness patterns, but adding an evolutionary perspectiveallows us to also considerthe historical processes determining current diversity patterns. We analyzedphylogenetic patternsof fern species assemblagesin 868 plots along a wide rangeof elevational (0-4000 m) and latitudinal (0°-23°N) gra...

The European rabbit (Oryctolagus cuniculus) is a key prey species in Mediterranean ecosystems. However, it is also considered a pest on many oceanic islands, even though its true abundance and ecological effects on different island habitats are poorly understood. We present data on rabbit abundance for the best-preserved habitats of the Canary Isla...

Several efforts have been made to understand nutrient ecology worldwide. However, Ca and Mg have received less attention, despite their function in important biological processes of plants, such us growth and photosynthesis. Few studies focus on fern nutrient ecology of foliar Ca and Mg. Moreover, none has investigated the variation of these elemen...

Functional traits determine how species interact with their abiotic and biotic environment. In turn, functional diversity describes how assemblages of species as a whole are adapted to their environment, which also determines how they might react to changing conditions. To fully understand functional diversity, it is fundamental to (a) disentangle...

Background : Species density along elevation gradients often shows hump-shaped patterns, but in-depth data for Myanmar is still not available. Aim : The first plot-based study to detect the elevational patterns of life forms and tree leaf traits, and their relation to environmental factors in Myanmar. Methods : All seed plant species were recorded...

Aim To assess the range size patterns of ferns and lycophytes along elevational gradients at different latitudes in an ecographical transition zone and search for predictors of range size from a set of environmental factors. Location Mexico, from 15° to 23° N. Taxon Ferns and lycophytes. Methods All terrestrial and epiphytic species were recorde...

Aim: To disentangle the influence of environmental factors at different spatial grains (regional and local) on fern and lycophyte species richness and ask how regional and plot-level richness are related to each other. Location: Global. Time period: Present. Major Taxa studied: Ferns and lycophytes. Methods: We explored fern and lycophyte species r...

Bryophytes have been proposed as ideal indicators of ecosystem change, because they are important components of forest integrity, and considerable research indicates that some groups are sensitive to the changes associated with specific human disturbances. Bryophyte richness and abundance have been found to vary predictably along elevational gradie...

List of species recorded in the study plots and occurrence (number of microplots in which the species was present) in each site (P: preserved, R: roadside and D: disturbed). (XLSX)

Aim: To assess richness patterns of ferns and lycophytes in relation to climatic factors in Eastern Asia, analysing eight elevational gradients, situated along a latitudinal gradient. Location: East and Southeast Asia (4° S to 43.3° N). Methods: Ferns and lycophytes were recorded in 480 plots of 400 m2 along eight elevational gradients. We related...

The transition zone from the tropics to the subtropics in Mexico is an outstanding and poorly explored area of biotic overlap, and as such very interesting to evaluate how species richness patterns change in the latitudinal context. In order to assess alpha diversity patterns of ferns in this zone, we analyzed changes in their assemblages along an...

Ecological aspects of bryophyte and lichen distributions were analyzed on Baru Volcano, Panama. At 8 elevations between 1900 and 3300m, thickness, biomass and water-holding capacity of the bryophyte/lichen layer were determined. All increased with elevation, but substrates differed. Those close to the ground (soil, rocks, logs) showed the strongest...

The Tropics are global centers of biodiversity. Ecological and land use gradients play a major role in the origin and maintenance of this diversity, yet a comprehensive synthesis of the corresponding large body of literature is still missing. We searched all ISI-listed journals for tropical gradient studies. From the resulting 1023 studies, we extr...

Although the montane forests of northern Myanmar are part of one of the most biodiverse areas of the world, our knowledge of species richness and elevational distribution of species within these forests is poor and scattered at both spatial and temporal scales. Over the last five decades, very few floristic assessments have been undertaken. This is...

Aim We used published data of the floristic and elevational distribution of seed plants of Bhutan to test the contribution of climatic, topographical and biogeographical variables to shape elevational species richness and endemism patterns. Location Bhutan. Methods We compiled data of seed plant species distributions from the Flora of Bhutan and...

We introduce a novel framework for conceptualising, quantifying and unifying discordant patterns of species richness along geographical gradients. While not itself explicitly mechanistic, this approach offers a path towards understanding mechanisms. In this study, we focused on the diverse patterns of species richness on mountainsides. We conjectur...

Evolutionary processes such as adaptation, ecological filtering, and niche conservatism involve the interaction of organisms with their environment and are thus commonly studied along environmental gradients. Elevational gradients have become among the most studied environmental gradients to understand large-scale patterns of species richness and c...

Managing ecosystems for carbon storage may also benefit biodiversity conservation, but such a potential 'win-win' scenario has not yet been assessed for tropical agroforestry landscapes. We measured above-and below-ground carbon stocks as well as the species richness of four groups of plants and eight of animals on 14 representative plots in Sulawe...

We describe Selliguea kachinensis as a new species from Northern Myanmar and discuss its generic placement in either Selliguea or Arthromeris. The conservation status is assessed as Data Deficient. In addition, we make the new combination Selliguea erythrocarpa (Mett. ex Kuhn) Hovenkamp, S. Linds., Fraser-Jenk.

We investigated if an increase in species pool size leads to more pronounced turnover in local communities and assessed if this increase relates to stronger competition for environmental niches or to more random placement of species. We compared compositional turnover of pteridophytes (ferns and lycophytes) at 15 sites in mountain ecosystems on 13...

The species richness–productivity relationship ( SRPR ), by which the species richness of habitats or ecosystems is related to the productivity of the ecosystem or the taxon, has been documented both on regional and local scales, but its generality, biological meaning and underlying mechanisms remain debated. We evaluated the SRPR and three mechani...

We studied tree height in stands of high-Andean Polylepis forests in two cordilleras near Cuzco (Peru) with respect to variations in human impact and climatic conditions, and compared air and soil temperatures between qualitatively defined dry and humid slopes. We studied 46 forest plots of 100 m² of five Polylepis species at 3560–4680 m. We measur...

Mycorrhizal fungi are crucial for the ecological success of land plants, providing their hosts with nutrients in exchange for organic C. However, not all plants are mycorrhizal, especially ferns, of which about one-third of the species lack this symbiosis. Because the mycorrhizal status is evolutionarily ancestral, this lack of mycorrhizae must hav...

We are launching a long-term study to characterize the biodiversity at different elevations in several Azorean Islands. Our aim is to use the Azores as a model archipelago to answer the fundamental question of what generates and maintains the global spatial heterogeneity of diversity in islands and to be able to understand the dynamics of change ac...

Background: Biodiversity is perceived to decline from lowlands towards mountain peaks and away from the Equator towards the Poles, but supporting data for most groups of organisms are lacking, especially at the local scale. Aims: Elevational gradients of fern species richness in tropical forest habitats were analysed to test the hypotheses that fer...

The morphologically variable tree fern Alsophila hornei of the Gymnosphaera clade is taxonomically and ecologically evaluated. While there is only one morphospecies present at the type locality on Fiji, three species can be characterized along an elevational transect on New Guinea. Alsophila hornei is also present at low elevations throughout New G...

Managing ecosystems for carbon storage may also benefit biodiversity conservation, but such a potential 'win-win' scenario has not yet been assessed for tropical agroforestry landscapes. We measured above- and below-ground carbon stocks as well as the species richness of four groups of plants and eight of animals on 14 representative plots in Sulaw...

Species richness in the study plots in relation to below-ground carbon stocks. Species richness of 12 groups of organisms in relation to below-ground (soil + root) carbon stocks in 14 plots of natural forest and cacao agroforests. Symbols as in Fig. S1. (TIF)

Species richness in the study plots in relation to above-ground carbon stocks. Species richness of 12 groups of organisms in relation to above-ground carbon stocks in 14 plots of natural forest and cacao agroforests. Symbols as in Fig. S1. (TIF)

Species richness of selected organisms in relation to total carbon stocks in the 14 plots. Species richness (number of species per plot) of 12 groups of organisms in relation to total carbon stocks in 14 plots of natural forest and cacao agroforests. Large black circles denote natural forest plots, small circles agroforests of varying tree density...

Strength of relation (R-values) between the individual number of bees and wasp and hummingbirds total against biotic and abiotic environmental factors during rainy (R) and dry season (D) and total; ^ p<0.1, * p≤0.05. (DOC)

Strength of relation (R-values) of linear regression analyses of the difference in species and individual numbers between seasons of the three pollinator groups and factors of climate and food seasonality; R = rainy season, D = dry season; ^ p<0.1, * p≤0.05. (DOC)

Strength of relation (R-values) for regression analysis between soil parameters and the number of pollinator group species and individuals of the different pollinator groups respectively number of food plant species and flowers during rainy (R) and dry season (D) and total; ^ p<0.1, * p≤0.05. (DOC)

Tropical South America is rich in different groups of pollinators, but the biotic and abiotic factors determining the geographical distribution of their species richness are poorly understood. We analyzed the species richness of three groups of pollinators (bees and wasps, butterflies, hummingbirds) in six tropical forests in the Bolivian lowlands...

Arid and Alpine ecosystems are known for extreme environmental changes during the Late Quaternary. We hypothesize that the world's largest Alpine arid ecosystem however, the Alpine Steppes of the Tibetan highlands, remained ecologically stable during the LGM and the mid-Holocene. This hypothesis is tested by distributional range of plant species, p...

Aim: To present a first description of plant communities of the Tibetan alpine steppes based on floristically complete vegetation records as a baseline reference for future ecological and palaeoecological studies. These constitute the world's largest alpine biome, but their vegetation is virtually unknown. Due to their vast extent, they are relevan...

An analysis of the fern vegetation on 156 plots along an elevational gradient (45-3400m) in undisturbed forests in Costa Rica, Central America, showed a hump-shaped pattern of species richness with a maximum of up to 68 species per 400m² at mid-elevations. This study documents the contribution of specific habitats (forest types: ridges, ravines) an...

1. Biodiversity data are needed for conservation and management of tropical habitats, but the high diversity of these ecosystems makes comprehensive surveys prohibitively expensive and indicator taxa reflecting the biodiversity patterns of other taxa are frequently used. Few studies have produced the necessary comprehensive data sets to assess the...

Aim Elevational gradients offer an outstanding opportunity to assess factors determining patterns of species richness, but along single transects potential explanatory factors often covary, making it difficult to distinguish between competing hypotheses. Many previous studies on plants have interpreted their results as supporting the mid-domain eff...

Aim To calculate the degree to which differences between local and regional elevational species richness patterns can be accounted for by the effects of regional area. Location Five elevational transects in Costa Rica, Ecuador, La Réunion, Mexico and Tanzania. Methods We sampled ferns in standardized field plots and collated regional species lists...

Tropical species with narrow elevational ranges may be thermally specialized and vulnerable to global warming. Local studies of distributions along elevational gradients reveal small-scale patterns but do not allow generalizations among geographic regions or taxa. We critically assessed data from 249 studies of species elevational distributions in...

Tropical species with narrow elevational ranges may be thermally specialized and vulnerable to global warming. Local studies of distributions along elevational gradients reveal small-scale patterns but do not allow generalizations among geographic regions or taxa. We critically assessed data from 249 studies of species elevational distributions in...

Aim To analyse the structure of pteridophyte assemblages, based on phylogenetic relatedness and trait properties, along an elevational gradient. Ecological theory predicts that co-occurring species may be: randomly selected from a regional pool; ecologically sorted so that they are functionally different hence resulting in reduced competition (over...

The colonisation of land by plants may not have been possible without mycorrhizae, which supply the majority of land plants with nutrients, water and other benefits. In this sense, the mycorrhization of basal groups of land plants such as ferns and lycophytes is of particular interest, yet only about 9% of fern and lycophyte species have been sampl...

Dispersal may influence the spatial distribution of species richness through mass or source-sink effects, but the extent of sink populations at the community level remains largely unknown due to difficulties of identifying such populations. We compared the richness patterns of ferns in 333 plots along six tropical elevational gradients in America,...

1. Sustainable management of rangelands will become increasingly important as the climate changes, yet rangeland dynamics are still a challenge to dryland ecologists because degradation patterns are difficult to sample and interpret. There are contradictions between remote sensing-based studies and field-based analyses, for which long-term data are...

Assessing the overall biological diversity of tropical rain forests is a seemingly insurmountable task for ecologists. Therefore, researchers frequently sample selected taxa that they believe reflect general biodiversity patterns. Usually, these studies focus on the congruence of alpha diversity (the number of species found per sampling unit) betwe...

The documentation and explanation of global and regional gradients of species richness is one of the major challenges of ecological and biogeographical research. In addition to the classical latitudinal richness gradient, patterns of species richness along elevational gradients have also received considerable attention in the last decade. As an alt...

The use of species turnover rates to identify discontinuities in vegetation assemblages along environmental gradients is hampered by the difficulty of the application of significance tests. We used a simulation procedure to detect abrupt transitions in fern species assemblages along a tropical elevational gradient to detect elevational zonations be...

It has recently been realized that the dominant pattern of plant and animal species richness along tropical elevational gradients is usually hump-shaped, with maximum richness at intermediate elevations (mostly between 500-2000 m). The causes determining these patterns are still poorly understood but most probably involve area, climatic variables s...

One of the major problems in assessing growth conditions of trees at upper tropical tree lines is that the vast majority of tree lines have been influenced or destroyed by human activities. Confronted with this situation, we modelled tree height of Polylepis trees in the Bolivian Andes correlating field data from 167 Polylepis stands and a climatic...

Aim. The biodiversity of geometrid moths (Lepidoptera) along a complete tropical elevational gradient was studied for the first time. The patterns are described, and the role of geometric constraints and environmental factors is explored. Location. The study was carried out along the Barva Transect (10°N, 84° W), a complete elevational gradient ran...

We studied the distribution patterns of endemic ferns along an elevational gradient of 3400 m in Costa Rica, Central America. We related the endemism patterns of the whole species set and separated for life forms and microhabitats according to topography and environmental factors. Fern species were surveyed in 156 plots each with an area of 400 m2,...

Aim We studied pteridophyte species richness between 100 m and 3400 m along a Neotropical elevational gradient and tested competing hypotheses for patterns of species richness. Location Elevational transects were situated at Volcán Barva in the Braulio Carrillo National Park and La Selva Biological Station (100–2800 m) and Cerro de la Muerte (2700–...