Microbes do not follow the elevational diversity patterns of plants and animals

The elevational gradient in plant and animal diversity is one of the most widely documented patterns in ecology and, although no consensus explanation exists, many hypotheses have been proposed over the past century to explain these patterns. Historically, research on elevational diversity gradients has focused almost exclusively on plant and animal taxa. As a result, we do not know whether microbes exhibit elevational gradients in diversity that parallel those observed for macroscopic taxa. This represents a key knowledge gap in ecology, especially given the ubiquity, abundance, and functional importance of microbes. Here we show that, across a montane elevational gradient in eastern Peru, bacteria living in three distinct habitats (organic soil, mineral soil, and leaf surfaces) exhibit no significant elevational gradient in diversity (r2<0.17, P>0.1 in all cases), in direct contrast to the significant diversity changes observed for plant and animal taxa across the same montane gradient (r2>0.75, P<0.001 in all cases). This finding suggests that the biogeographical patterns exhibited by bacteria are fundamentally different from those of plants and animals, highlighting the need for the development of more inclusive concepts and theories in biogeography to explain these disparities.     

Global biodiversity patterns of benthic marine algae

Species richness patterns are remarkably similar across many marine taxa, yet explanations of how such patterns are generated and maintained are conflicting. I use published occurrence data to identify previously masked latitudinal and longitudinal diversity gradients for all genera of benthic marine macroalgae and for species in the Order Bryopsidales. I also quantify the size, location, and overlap of macroalgal geographic ranges to determine how the observed richness patterns are generated. Algal genera exhibit an inverse latitudinal gradient, with biodiversity hotspots in temperate regions, while bryopsidalean species reach peak diversity in the tropics. The geographic distribution of range locations results in distinct clusters of range mid-points. In particular, widespread taxa are centered within tight latitudinal and longitudinal bands in the middle of the Indo-Pacific and Atlantic Oceans while small-ranged taxa are clustered in peripheral locations, suggesting that variation in speciation and extinction are important drivers of algal diversity patterns. Hypotheses about factors that regulate diversity contain underlying assumptions about the size and location of geographic ranges, in addition to predictions as to why species numbers will differ among regions. Yet these assumptions are rarely considered in assessing the validity of the prevailing hypotheses. I assess a suite of hypotheses, suggested to explain patterns of marine diversity, by comparing algal-richness patterns in combination with the size and location of algal geographic ranges, to the richness and range locations predicted by these hypotheses. In particular, the results implicate habitat areas and ocean currents as the most plausible drivers of observed diversity patterns.     

Spatial mismatch between wild bee diversity hotspots and protected areas

Wild bees are critical for multiple ecosystem functions but are currently threatened. Understanding the determinants of the spatial distribution of wild bee diversity is a major research gap for their conservation. We modeled wild bee α and β taxonomic and functional diversity in Switzerland to uncover countrywide diversity patterns and determine the extent to which they provide complementary information, assess the importance of the different drivers structuring wild bee diversity, identify hotspots of wild bee diversity, and determine the overlap between diversity hotspots and the network of protected areas. We used site-level occurrence and trait data from 547 wild bee species across 3343 plots and calculated community attributes, including taxonomic diversity metrics, community mean trait values, and functional diversity metrics. We modeled their distribution with predictors describing gradients of climate, resource availability (vegetation), and anthropogenic influence (i.e., land-use types and beekeeping intensity). Wild bee diversity changed along gradients of climate and resource availability; high-elevation areas had lower functional and taxonomic α diversity, and xeric areas harbored more diverse bee communities. Functional and taxonomic β diversities diverged from this pattern, with high elevations hosting unique species and trait combinations. The proportion of diversity hotspots included in protected areas depended on the biodiversity facet, but most diversity hotspots occurred in unprotected land. Climate and resource availability gradients drove spatial patterns of wild bee diversity, resulting in lower overall diversity at higher elevations, but simultaneously greater taxonomic and functional uniqueness. This spatial mismatch among distinct biodiversity facets and the degree of overlap with protected areas is a challenge to wild bee conservation, especially in the face of global change, and calls for better integrating unprotected land. The application of spatial predictive models represents a valuable tool to aid the future development of protected areas and achieve wild bee conservation goals.     

Variation in species losses from islands: artifacts, extirpation rates, or pre-fragmentation diversity?

Species are being lost from isolated reserves as predicted by ecological theory, prompting calls for larger reserves with higher species immigration rates. However, some large islands have lost a large proportion of their species, whereas some small islands have not lost any. Conservation efforts would be more efficient if the cause of such variation in the relationships among number of species lost, island size, and immigration rate were known. Observed species losses could be affected by the time since islands were isolated, species immigration rates, species extirpation rates, the pre-fragmentation diversity of the region relative to steady state, or overestimation of the pre-fragmentation diversity of islands. To test the last three hypotheses, I compared the intersection points of the island, intraprovincial, and interprovincial species-area relationships of terrestrial mammals from nine archipelagos of land-bridge islands and terrestrial habitat isolates. Species losses from three archipelagos were greater than expected due to reduced immigration rates alone, although I could not resolve if this was due to increased extirpation rates or overestimation of the pre-fragmentation diversity of the islands. Analysis of six archipelagos indicates that the diversity of mammals in two regions of North America is currently below steady state, probably due to the extinction of mammals and glacial retreat during the late Pleistocene. These results have direct implications for reserve planning. When provincial diversity is below steady state, some combinations of reserve size and species immigration rate will allow reserves to maintain their pre-isolation diversity. However, the diversity of provinces relative to steady state is likely to vary, so conservation of a given proportion of a province may not always conserve the same proportion of its species. I present a new species-area relationship for islands formed by fragmentation that replaces the parameter c (fitted constant) with a rotation point. Estimation of this rotation point will allow reserve planners to separate the effects of extirpation and immigration rates on species losses from islands, identify provinces that are below steady-state diversity, and estimate the combinations of reserve size and immigration rate that will prevent loss of species from reserves.     

Patterns of Genetic Diversity and Its Loss in Mammalian Populations

Abstract:  Policy aimed at conserving biodiversity has focused on species diversity. Loss of genetic diversity, however, can affect population persistence, evolutionary potential, and individual fitness. Although mammals are a well-studied taxonomic group, a comprehensive assessment of mammalian genetic diversity based on modern molecular markers is lacking. We examined published microsatellite data from populations of 108 mammalian species to evaluate background patterns of genetic variability across taxa and body masses. We tested for loss of genetic diversity at the population level by asking whether populations that experienced demographic threats exhibited lower levels of genetic diversity. We also evaluated the effect of ascertainment bias (a reduction in variability when microsatellite primers are transferred across species) on our assessment of genetic diversity. Heterozygosity did not vary with body mass across species ranging in size from shrews to whales. Differences across taxonomic groupings were noted at the highest level, between populations of marsupial and placental mammals. We documented consistently lower heterozygosity, however, in populations that had experienced demographic threats across a wide range of mammalian species. We also documented a significant ( p = 0.01) reduction in heterozygosity as a result of ascertainment bias. Our results suggest that populations of both rare and common mammals are currently losing genetic diversity and that conservation efforts focused above the population level may fail to protect the breadth of persisting genetic diversity. Conservation policy makers may need to focus their efforts below the species level to stem further losses of genetic resources.     

Global Patterns of Mammalian Diversity, Endemism, and Endangerment

To assess the conservation status of the world's land mammals, we compiled data on the number of total species, endemic species, recently extinct species, and currently endangered species for 155 countries. Total species richness was significantly correlated with territorial land area, whereas number of endemic species was only weakly correlated with both area and total number of species. The large amount of variation left unexplained by species-area regressions reflects the influence of other factors, such as latitude, topographic and habitat heterogeneity, and historical biogeography, on species richness and especially on patterns of endemism. Countries of particular conservation concern, because they have rich mammalian faunas containing many endemic species, are the large islands of Australia, Madagascar, Indonesia, and the Philippines, as well as continental Mexico. Patterns of recent extinctions and the current endangered status of species were difficult to interpret, largely because of inadequate and inconsistent data. The majority of officially listed endangered species are large, well known, and popular mammals, such as primates, ungulates, and carnivores, whereas the majority of species known to have gone recently extinct and likely to be currently threatened are small and inconspicuous, such as rodents and bats. Our work not only illustrates the role of ecological, evolutionary, and biogeographic processes in the origin and maintenance of land mammal diversity, it also presents the information at the level of biogeographic regions and political units where management and policy must be applied in order to slow the loss of this diversity.     

Zooplankton biodiversity and lake trophic state: explanations invoking resource abundance and distribution

While empirical studies linking biodiversity to local environmental gradients have emphasized the importance of lake trophic status (related to primary productivity), theoretical studies have implicated resource spatial heterogeneity and resource relative ratios as mechanisms behind these biodiversity patterns. To test the feasibility of these mechanisms in natural aquatic systems, the biodiversity of crustacean zooplankton communities along gradients of total phosphorus (TP) as well as the vertical heterogeneity and relative abundance of their phytoplankton resources were assessed in 18 lakes in Quebec, Canada. Zooplankton community richness was regressed against TP, the spatial distribution of phytoplankton spectral groups, and the relative biomass of spectral groups. Since species richness does not adequately capture ecological function and life history of different taxa, features which are important for mechanistic theories, relationships between zooplankton functional diversity (FD) and resource conditions were examined. Zooplankton species richness showed the previously established tendency to a unimodal relationship with TP, but functional diversity declined linearly over the same gradient. Changes in zooplankton functional diversity could be attributed to changes in both the spatial distribution and type of phytoplankton resource. In the studied lakes, spatial heterogeneity of phytoplankton groups declined with TP, even while biomass of all groups increased. Zooplankton functional diversity was positively related to increased heterogeneity in cyanobacteria spatial distribution. However, a smaller amount of variation in functional diversity was also positively related to the ratio of biomass in diatoms/chrysophytes to cyanobacteria. In all observed relationships, a greater variation of functional diversity than species richness measures was explained by measured factors, suggesting that functional measures of zooplankton communities will benefit ecological research attempting to identify mechanisms behind environmental gradients affecting diversity.     

Interhemispheric comparison of recruitment to intertidal communities: pattern persistence and scales of variation

Recruitment variation can be a major source of fluctuation in populations and communities, making it difficult to generalize results. Determining the scales of variation and whether spatial patterns in the supply of individuals are persistent over time can provide insight into spatial generality and the application of conservation and metacommunity models. We examined these issues using eight-year-long data sets of monthly recruitment of intertidal mussels (Mytilus spp., Perumytilus purpuratus, Semimytilus algosus, Brachidontes granulata) and barnacles (Balanus glandula, Chthamalus dalli, Jehlius cirratus, Notochthamalus scabrosus) at sites spanning > 900 km along the coasts of Oregon-northern California (OR-NCA, 45.47-39.43 degrees N) and central Chile (CC, 29.5-34.65 degrees S). We evaluated four general "null" hypotheses: that despite different phylogenies and great spatial separation of these taxa, their similar life history strategies and environmental settings lead to similar patterns of recruitment (1) between hemispheres, (2) in time, (3) in space, and (4) at larger and smaller spatial scales. Hypothesis 1 was rejected: along the OR-NCA coast, rates of recruitment were between two and three orders of magnitude higher, and patterns of seasonality were generally stronger and more coherent across space and time than along CC. Surprisingly, however, further analysis revealed regularities in both time and space for all species, supporting hypotheses 2 and 3. Temporal decorrelation scales were 1-3 months, and characteristic spatial scales of recruitment were approximately 250 km. Contrary to hypothesis 4, for the ecologically dominant species in both hemispheres, recruitment was remarkably persistent at larger mesoscales (kilometers) but was highly stochastic at smaller microscales (meters). Across species, increased recruitment variation at large scales was positively associated with increased persistence. Our results have several implications. Although the two regions span distinct latitudinal ranges, potential forcing processes behind these patterns include similar large-scale climates and topographically locked hydrographic features, such as upwelling. Further, spatial persistence of the recruitment patterns of most species at the mesoscale supports the view that marine protected areas can be powerful conservation and management tools. Finally, persistent and yet contrasting spatial patterns of recruitment among competing species suggest that recent metacommunity models might provide useful representations of the mechanisms involved in species coexistence.     

A multivariate analysis of beta diversity across organisms and environments

We examined variability in hierarchical beta diversity across ecosystems, geographical gradients, and organism groups using multivariate spatial mixed modeling analysis of two independent data sets. The larger data set comprised reported ratios of regional species richness (RSR) to local species richness (LSR) and the second data set consisted of RSR:LSR ratios derived from nested species-area relationships. There was a negative, albeit relatively weak, relationship between beta diversity and latitude. We found only relatively subtle differences in beta diversity among the realms, yet beta diversity was lower in marine systems than in terrestrial or freshwater realms. Beta diversity varied significantly among organisms' major characteristics such as body mass, trophic position, and dispersal type in the larger data set. Organisms that disperse via seeds had highest beta diversity, and passively dispersed organisms showed the lowest beta diversity. Furthermore, autotrophs had lower beta diversity than organisms higher up the food web; omnivores and carnivores had consistently higher beta diversity. This is evidence that beta diversity is simultaneously controlled by extrinsic factors related to geography and environment, and by intrinsic factors related to organism characteristics.     

Use of historical and contemporary distribution of mammals in China to inform conservation

A systematic understanding of dynamic animal extinction trajectories for different regions in a nation like China is critically important to developing practical conservation strategies. We explored historical and contemporary changes in terrestrial mammalian diversity to determine how diversity in each of the 5 regions in China has changed over time and to examine the conservation potential of these regions. We used records from databases on Pleistocene mammalian fossils and historical distribution records (1175–2020) for Primates (as a case study) to reconstruct evolutionary and historical distribution trajectories of the 11 orders of terrestrial mammals and to predict their prospective survival based on the national conservation strategy applied. The results indicated that since the Pleistocene, 4–5 mammalian orders have been lost in the northeast, 3 in central China, 2 along the coast, and 1 in the northwest. In the southwest, all 11 orders were maintained. Contemporarily, the coast and southwest had the highest and second-highest species densities. The southwest region and southeastern sections of the northwest region were the most historically and contemporarily diverse areas, which suggests that they should be the first priority for protected area (PA) designation. The central and coastal areas should be secondarily prioritized. In these 2 regions, conservation should focus on human coexistence with nature. Less attention should be paid to the PA in the northeast and western northwest because in these areas ecosystems are depauperate and the climate is harsh. Conservation in these areas should focus principally on avoiding further human encroachment on natural areas. Article impact statement: Historical and contemporary patterns of extinction can be a basis for mammalian conservation strategies.     

Latitudinal gradients in species richness for South American Mytilidae and Ostreidae: can alternative hypotheses be evaluated by a correlative approach?

We tested to what extent mean sea surface temperature, geometric constraints in range size frequency distributions (the mid-domain effect) and geographical coastline distance to the equator are related to species richness of coastal Mytilidae and Ostreidae in the Pacific and Atlantic coasts of South America (excluding islands). The location and magnitude of the peaks in species richness, as well as the shape of the pattern, varied between oceans. Results were not biased by spatial autocorrelation, although strong multicollinearity among predictor variables was detected. However, these regional-extent regression models suggest differences in the causal factors that explain richness gradients of studied bivalves in South American coasts, most likely related to historical events such as the Southeastern Pacific Pleistocene mass extinction of bivalves. Our results reinforced the conclusion that there is no single best explanatory cause for the latitudinal gradient in species richness and showed that the correlative approach is not useful when predictor variables are strongly correlated.     

Trait similarity patterns within grass and grasshopper communities: multitrophic community assembly at work

Trait-based community assembly theory suggests that trait variation among co-occurring species is shaped by two main processes: abiotic filtering, important in stressful environments and promoting similarity, and competition, more important in productive environments and promoting dissimilarity. Previous studies have indeed found trait similarity to decline along productivity gradients. However, these studies have always been done on single trophic levels. Here, we investigated how interactions between trophic levels affect trait similarity patterns along environmental gradients. We propose three hypotheses for the main drivers of trait similarity patterns of plants and herbivores along environmental gradients: (1) environmental control of both, (2) bottom-up control of herbivore trait variation, and (3) top-down control of grass trait variation. To test this, we collected data on the community composition and trait variation of grasses (41 species) and grasshoppers (53 species) in 50 plots in a South African savanna. Structural equation models were used to investigate how the range and spacing of within-community functional trait values of both grasses and their insect herbivores (grasshoppers; Acrididae) respond to (1) rainfall and fire frequency gradients and (2) the trait similarity patterns of the other trophic level. The analyses revealed that traits of co-occurring grasses became more similar toward lower rainfall and higher fire frequency (environmental control), while showing little evidence for top-down control. Grasshopper trait range patterns, on the other hand, were mostly directly driven by vegetation structure and grass trait range patterns (bottom-up control), while environmental factors had mostly indirect effects via plant traits. Our study shows the potential to expand trait-based community assembly theory to include trophic interactions.     

A hidden species-area curve

The species-area curve, which describes the relationship between the number of observed species in a geographical region and the area of the region, plays a central role in biogeography. Beyond its scientific importance, the species-area curve is commonly used to assess the loss of species due to habitat loss. When the species-area curve is estimated from spatial samples, the existence of species with low or highly spatially variable abundance exaggerates the true rate at which species accumulate with area. Here, a hidden species-area curve is defined that accounts for this sampling effect and its estimation by maximum likelihood is outlined. Both the species-area curve and the hidden species-area curve are conditioned on the observed species list; thus the analysis does not depend on the total number of observed and unobserved species, that is, species richness. The method is tested by sub-sampling some tropical forest data and found to work well. It is also applied to a classic data set from the deep sea. For these data, accounting for this sampling effect has a large impact.     

Geographical gradients of marine herbivorous fishes: patterns and processes

We present new data and the first rigorous analysis of latitudinal and thermal gradients of diversity, density and biomass of marine herbivorous fishes and review proposed explanatory mechanisms. Consistently, negative relationships between latitude, and positive relationships between sea surface temperature (SST), and relative richness and relative abundance of herbivorous fishes were found worldwide. Significant differences in the strength of gradients of richness and abundance with latitude and SST between tropical and extratropical zones were found consistently across ocean basins. Standardized sampling along the western Atlantic also showed negative relationships between latitude and total density and biomass. The trends, however, are driven by different components of the fish assemblages (i.e., scarids in the Caribbean and acanthurids in Brazil). Patterns of abundance along thermal gradients, generally associated with extensive latitudinal gradients, also were found at the local scale. Feeding rate of the ocean surgeonfish Acanthurus bahianus decreases with temperature more rapidly than the mean metabolic rate of teleost fishes. This relationship suggests a temperature-related physiological constraint. From the new standardized and comparative data presented and the review of the explanatory hypotheses, we conclude that temperature-related feeding and digestive processes are most likely involved in the distribution patterns of herbivorous fishes. Electronic Supplementary Material Supplementary material is available for this article at     

Modeling the beta diversity of coral reefs

Quantifying the beta diversity (species replacement along spatiotemporal gradients) of ecosystems is important for understanding and conserving patterns of biodiversity. However, virtually all studies of beta diversity focus on one-dimensional transects orientated along a specific environmental gradient that is defined a priori. By ignoring a second spatial dimension and the associated changes in species composition and environmental gradients, this approach may provide limited insight into the full pattern of beta diversity. Here, we use remotely sensed imagery to quantify beta diversity continuously, in two dimensions, and at multiple scales across an entire tropical marine seascape. We then show that beta diversity can be modeled (0.852 > or = r2 > or = 0.590) at spatial scales between 0.5 and 5.0 km2, using the environmental variables of mean and variance of depth and wave exposure. Beta diversity, quantified within a "window" of a given size, is positively correlated to the range of environmental conditions within that window. For example, beta diversity increases with increasing variance of depth. By analyzing such relationships across seascapes, this study provides a framework for a range of disparate coral reef literature including studies of zonation, diversity, and disturbance. Using supporting evidence from soft-bottom communities, we hypothesize that depth will be an important variable for modeling beta diversity in a range of marine systems. We discuss the implications of our results for the design of marine reserves.     

Bird metacommunities in temperate South American forest: vegetation structure, area, and climate effects

Spatial structure in metacommunities and their relationships to environmental gradients have been linked to opposing theories of community assembly. In particular, while the species sorting hypothesis predicts strong environmental influences, the neutral theory, the mass effect, and the patch dynamics frameworks all predict differing degrees of spatial structure resulting from dispersal and competition limitations. Here we study the relative influence of environmental gradients and spatial structure in bird assemblages of the Chilean temperate forest. We carried out bird and vegetation surveys in South American temperate forests at 147 points located in nine different protected areas in central Chile, and collected meteorological and productivity data for these localities. Species composition dissimilarities between sites were calculated, as well as three indices of bird local diversity: observed species richness, Chao estimate of richness, and Shannon diversity. A stepwise multiple regression and partial regression analyses were used to select a small number of environmental factors that predicted bird species diversity. Although diversity indices were spatially autocorrelated, environmental factors were sufficient to account for this autocorrelation. Moreover, community dissimilarities were not significantly related to distance between sites. We then tested a multivariate hypothesis about climate, vegetation, and avian diversity interactions using a structural equation modeling (SEM) approach. The SEM showed that climate and area of fragments have important indirect effects on avian diversity, mediated through changes in vegetation structure. Given the scale of this study, the metacommunity framework provides useful insights into the mechanisms driving bird assemblages in this region. Taken together, the weak spatial structure of community composition and diversity, as well as the strong environmental effects on bird diversity, support the interpretation that species sorting has a predominant role in structuring avian assemblages in the region.     

Seed predation by Neotropical rain forest mammals increases diversity in seedling recruitment

Seed dispersal and seedling recruitment (the transition of seeds to seedlings) set the spatiotemporal distribution of new individuals in plant communities. Many terrestrial rain forest mammals consume post-dispersal seeds and seedlings, often inflicting density-dependent mortality. In part because of density-dependent mortality, diversity often increases during seedling recruitment, making it a critical stage for species coexistence. We determined how mammalian predators, adult tree abundance, and seed mass interact to affect seedling recruitment in a western Amazonian rain forest. We used exclosures that were selectively permeable to three size classes of mammals: mice and spiny rats (weighing <1 kg), medium-sized rodents (1-12 kg), and large mammals (20-200 kg). Into each exclosure, we placed seeds of 13 tree species and one canopy liana, which varied by an order of magnitude in adult abundance and seed mass. We followed the fates of the seeds and resulting seedlings for at least 17 months. We assessed the effect of each mammalian size class on seed survival, seedling survival and growth, and the density and diversity of the seedlings that survived to the end of the experiment. Surprisingly, large mammals had no detectable effect at any stage of seedling recruitment. In contrast, small- and medium-sized mammals significantly reduced seed survival, seedling survival, and seedling density. Furthermore, predation by small mammals increased species richness on a per-stem basis. This increase in diversity resulted from their disproportionately intense predation on common species and large-seeded species. Small mammals thereby generated a rare-species advantage in seedling recruitment, the critical ingredient for frequency dependence. Predation by small (and to a lesser extent, medium-sized) mammals on seeds and seedlings significantly increases tree species diversity in tropical forests. This is the first long-term study to dissect the effects of various mammalian predators on the recruitment of a diverse set of tree species.     

Are Swiss birds tracking climate change?: Detecting elevational shifts using response curve shapes

Climate change is affecting biodiversity worldwide inducing species to either “move, adapt or die”. In this paper we propose a conceptual framework for analysing range shifts, namely a catalogue of the possible patterns of change in the distribution of a species along elevational or other environmental gradients and an improved quantitative methodology to identify and objectively describe these patterns. Patterns are defined in terms of changes occurring at the leading, trailing or both edges of the distribution: (a) leading edge expansion, (b) trailing edge retraction, (c) range expansion, (d) optimum shift, (e) expansion, (f) retraction, and (g) shift. The methodology is based on the modelling of species distributions along a gradient using generalized additive models (GAMs). Separate models are calibrated for two distinct periods of assessment and response curves are compared over five reference points. Changes occurred at these points are formalized into a code that ultimately designates the corresponding change pattern. We tested the proposed methodology using data from the Swiss national common breeding bird survey. The elevational distributions of 95 bird species were modelled for the periods 1999-2002 and 2004-2007 and significant upward shifts (all patterns confounded) were identified for 35% of the species. Over the same period, an increase in mean temperature was registered for Switzerland. In consideration of the short period covered by the case study, assessed change patterns are considered to correspond to intermediate patterns in an ongoing shifting process. However, similar patterns can be determined by habitat barriers, land use/land cover changes, competition with concurrent or invasive species or different warming rates at different elevations.     

大空间尺度上物种多样性的分布规律

物种多样性是生物多样性在物种水平上的表现形式.由于全球性保护行动的开展和多学科的相互渗透,把物种多样性研究推向大时空尺度方向发展,一些新的研究领域得到拓展.本文综述了物种多样性在大空间尺度上的经典研究(包括梯度变化格局、个体大小频次分布格局和物种-面积关系),同时着重探讨了经典研究的新认识及一些新领域内所揭示的新格局,主要有:生物类群间物种数的协同变化、物种和高级分类阶元的关系、局域物种多样性与区域物种多样性关系以及全球变化影响等等.参79