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result(s) for
"diversity patterns"
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Large-Scale Spatial Distribution Patterns of Echinoderms in Nearshore Rocky Habitats
2010
This study examined echinoderm assemblages from nearshore rocky habitats for large-scale distribution patterns with specific emphasis on identifying latitudinal trends and large regional hotspots. Echinoderms were sampled from 76 globally-distributed sites within 12 ecoregions, following the standardized sampling protocol of the Census of Marine Life NaGISA project (www.nagisa.coml.org). Sample-based species richness was overall low (<1-5 species per site), with a total of 32 asteroid, 18 echinoid, 21 ophiuroid, and 15 holothuroid species. Abundance and species richness in intertidal assemblages sampled with visual methods (organisms >2 cm in 1 m(2) quadrats) was highest in the Caribbean ecoregions and echinoids dominated these assemblages with an average of 5 ind m(-2). In contrast, intertidal echinoderm assemblages collected from clearings of 0.0625 m(2) quadrats had the highest abundance and richness in the Northeast Pacific ecoregions where asteroids and holothurians dominated with an average of 14 ind 0.0625 m(-2). Distinct latitudinal trends existed for abundance and richness in intertidal assemblages with declines from peaks at high northern latitudes. No latitudinal trends were found for subtidal echinoderm assemblages with either sampling technique. Latitudinal gradients appear to be superseded by regional diversity hotspots. In these hotspots echinoderm assemblages may be driven by local and regional processes, such as overall productivity and evolutionary history. We also tested a set of 14 environmental variables (six natural and eight anthropogenic) as potential drivers of echinoderm assemblages by ecoregions. The natural variables of salinity, sea-surface temperature, chlorophyll a, and primary productivity were strongly correlated with echinoderm assemblages; the anthropogenic variables of inorganic pollution and nutrient contamination also contributed to correlations. Our results indicate that nearshore echinoderm assemblages appear to be shaped by a network of environmental and ecological processes, and by the differing responses of various echinoderm taxa, making generalizations about the patterns of nearshore rocky habitat echinoderm assemblages difficult.
Journal Article
Contrasting patterns in elevational diversity between microorganisms and macroorganisms
by
Soininen, Janne
,
Yang, Xiangdong
,
Shen, Ji
in
Animal and plant ecology
,
Animal, plant and microbial ecology
,
autocorrelation
2011
Aim Data and analyses of elevational gradients in diversity have been central to the development and evaluation of a range of general theories of biodiversity. Elevational diversity patterns have, however, been severely understudied for microbes, which often represent decomposer subsystems. Consequently, generalities in the patterns of elevational diversity across different trophic levels remain poorly understood. Our aim was to examine elevational gradients in the diversity of macroinvertebrates, diatoms and bacteria along a stony stream that covered a large elevational gradient. Location Laojun Mountain, Yunnan province, China. Methods The sampling scheme included 26 sites spaced at elevational intervals of 89 m from 1820 to 4050 m elevation along a stony stream. Macroinvertebrate and diatom richness were determined based on the morphology of the specimens. Taxonomic richness for bacteria was quantified using a molecular fingerprinting method. Over 50 environmental variables were measured at each site to quantify environmental variables that could correlate with the patterns of diversity. We used eigenvector-based spatial filters with multiple regressions to account for spatial autocorrelation. Results The bacterial richness followed an unexpected monotonic increase with elevation. Diatoms decreased monotonically, and macroinvertebrate richness showed a clear unimodal pattern with elevation. The unimodal richness pattern for macroinvertebrates was best explained by the mid-domain effect (r² = 0.72). The diatom richness was best explained by the variation in nutrient supply, and the increase in bacterial richness with elevation may be related to an increased carbon supply. Main conclusions We found contrasting patterns in elevational diversity among the three studied multi-trophic groups comprising unicellular and multicellular aquatic taxa. We also found that there may be fundamental differences in the mechanisms underlying these species diversity patterns.
Journal Article
Moth Diversity Increases along a Continent-Wide Gradient of Environmental Productivity in South African Savannahs
by
Vincent Maicher
,
Ondřej Sedláček
,
David Hořák
in
abundance
,
abundance; Afrotropics; Heterocera; insect; diversity patterns; light trapping; lepidoptera; NDVI; primary productivity; savannah ecosystems
,
Afrotropics
2022
Environmental productivity, i.e., the amount of biomass produced by primary producers, belongs among the key factors for the biodiversity patterns. Although the relationship of diversity to environmental productivity differs among studied taxa, detailed data are largely missing for most groups, including insects. Here, we present a study of moth diversity patterns at local and regional scales along a continent-wide gradient of environmental productivity in southern African savannah ecosystems. We sampled diversity of moths (Lepidoptera: Heterocera) at 120 local plots along a gradient of normalized difference vegetation index (NDVI) from the Namib Desert to woodland savannahs along the Zambezi River. By standardized light trapping, we collected 12,372 specimens belonging to 487 moth species. The relationship between species richness for most analyzed moth groups and environmental productivity was significantly positively linear at the local and regional scales. The absence of a significant relationship of most moth groups’ abundance to environmental productivity did not support the role of the number of individuals in the diversity–productivity relationship for south African moths. We hypothesize the effects of water availability, habitat complexity, and plant diversity drive the observed moth diversity patterns.
Journal Article
Global patterns and environmental correlates of high-priority conservation areas for vertebrates
2015
Aim: A major challenge for the emerging discipline of conservation biogeography is to identify conservation areas and understand the factors and processes that govern the spatial distribution of those areas. We aimed to identify highpriority conservation cells (HPCC) — 1° cells that efficiently represent species — for amphibians, birds and mammals at the global extent, to identify the environmental variables associated with conservation priority, and to evaluate how well the areas of highest species richness correspond to these high-priority areas. Location: A global analysis. Methods: Distribution maps for 21,697 vertebrates and complementarity-based approaches were used to map HPCCs for vertebrates. We used 41 potential predictor variables and varimax-rotated factor analysis (VrFA) to identify sets of relatively uncorrelated environmental factors, and then used random forest models to investigate the relationships between VrFA factors and vertebrate conservation priorities. Finally, we evaluated whether species richness and threatened-species richness were efficient surrogates to identify HPCCs for each vertebrate taxon. Results: For each of the three taxa, HPCCs were concentrated in the Neotropical, Afrotropical and Indo-Malay biogeographical realms. The spatial distribution of HPCCs was strongly correlated with environmental variables, especially energy-related variables. The cells with the highest species richness did not correspond to HPCCs for either birds or mammals. Discussion We suggest that elucidating the patterns and drivers of conservation priority could become a major focus of conservation biogeography. The ability to identify high-priority conservation sites from the environmental conditions in those sites may improve how sites are prioritized for conservation, so that all or most species can be conserved in affordable areas.
Journal Article
Exotic plant species invade hot spots of native plant diversity
by
Stohlgren, Thomas J.
,
Chong, Geneva W.
,
Newman, Gregory
in
Animal, plant and microbial ecology
,
Applied ecology
,
autocorrelation
1999
Some theories and experimental studies suggest that areas of low plant species richness may be invaded more easily than areas of high plant species richness. We gathered nested-scale vegetation data on plant species richness, foliar cover, and frequency from 200 1-m2subplots (20 1000-m2modified-Whittaker plots) in the Colorado Rockies (USA), and 160 1-m2subplots (16 1000-m2plots) in the Central Grasslands in Colorado, Wyoming, South Dakota, and Minnesota (USA) to test the generality of this paradigm. At the 1-m2scale, the paradigm was supported in four prairie types in the Central Grasslands, where exotic species richness declined with increasing plant species richness and cover. At the 1-m2scale, five forest and meadow vegetation types in the Colorado Rockies contradicted the paradigm; exotic species richness increased with native-plant species richness and foliar cover. At the 1000-m2plot scale (among vegetation types), 83% of the variance in exotic species richness in the Central Grasslands was explained by the total percentage of nitrogen in the soil and the cover of native plant species. In the Colorado Rockies, 69% of the variance in exotic species richness in 1000-m2plots was explained by the number of native plant species and the total percentage of soil carbon. At landscape and biome scales, exotic species primarily invaded areas of high species richness in the four Central Grasslands sites and in the five Colorado Rockies vegetation types. For the nine vegetation types in both biomes, exotic species cover was positively correlated with mean foliar cover, mean soil percentage N, and the total number of exotic species. These patterns of invasibility depend on spatial scale, biome and vegetation type, spatial autocorrelation effects, availability of resources, and species-specific responses to grazing and other disturbances. We conclude that: (1) sites high in herbaceous foliar cover and soil fertility, and hot spots of plant diversity (and biodiversity), are invasible in many landscapes; and (2) this pattern may be more closely related to the degree resources are available in native plant communities, independent of species richness. Exotic plant invasions in rare habitats and distinctive plant communities pose a significant challenge to land managers and conservation biologists.
Journal Article
Using Soundscapes to Assess Changes in Coral Reef Social-Ecological Systems
by
Lin, Tzu-Hao
,
Harii, Saki
,
Akamatsu, Tomonari
in
Anthropogenic factors
,
Biodiversity
,
Climate change
2023
Coral reefs are among the world’s most diversified marine ecosystems. While their rich biodiversity is essential to many social and economic activities, they face unprecedented cumulative impacts from climate change and anthropogenic development. Aligning governance structures with ecological processes has become key to sustaining ecosystem services. Nevertheless, a major obstacle to informing decision-making is the lack of empirical data on interacting ecological and social processes. Therefore, novel methods for facilitating the assessment of coral reef social-ecological systems are necessary.
Journal Article
UAV High-Resolution Imaging and Disease Surveys Combine to Quantify Climate-Related Decline in Seagrass Meadows
by
Rappazzo, Brendan
,
Aoki, Lillian R.
,
Duffy, J. Emmett
in
Biodiversity
,
Carbon sequestration
,
Diseases
2023
Seagrass meadows are essential habitats that support marine biodiversity and coastal communities while sequestering carbon, filtering water, and stabilizing coastal sediments. Warming temperatures stress seagrass meadows and can facilitate seagrass wasting disease, contributing to large-scale diebacks of seagrass meadows. Here, we demonstrate how high-resolution imagery, collected by uncrewed aerial vehicle (UAV) and validated by in situ sampling, can quantify seagrass responses to disease and thermal stress.
Journal Article
Mesophotic coral ecosystems of French Polynesia are hotspots of alpha and beta generic diversity for scleractinian assemblages
by
Pérez-Rosales, Gonzalo
,
Hédouin, Laetitia
,
Bongaerts, Pim
in
Archipelagoes
,
Biodiversity
,
coral genus biodiversity
2022
Aim Revealing how diversity varies across the depth gradient is key for understanding the role of mesophotic coral ecosystems in the functioning of coral reefs. We quantitatively examined how alpha and beta generic diversity of scleractinian coral assemblages vary across a wide depth gradient for coral reefs. Location Sixteen sites in eight islands of three archipelagos in French Polynesia. Methods We studied generic diversity patterns of scleractinian corals, as derived from the analysis of photo‐quadrats, across the seafloor from shallow to lower mesophotic depths (6–120 m) and on a wide geographic scale. Our sampling considered quantitative coral cover to explore the patterns of alpha and beta components of diversity across depth and horizontal space. Results We show that in French Polynesia, mesophotic coral ecosystems host higher alpha and beta generic diversity than shallow reefs despite decreasing coral cover with depth. The variation of coral genus richness across the depth gradient is mainly driven by a mid‐domain effect with a peak at 40 m depth. At the same time, we found that the differences in coral genera across islands (spatial beta‐diversity) increased steadily along the depth gradient. Main conclusions Our findings report the first quantitative results of coral cover and diversity from mesophotic coral ecosystems in French Polynesia and also present one of the few existing studies to examine the broad breadth of the mesophotic depth gradient. We demonstrate that mesophotic depths can host unexpectedly high generic richness of scleractinian coral assemblages. At the same time, we showed that increasing depth increases the differences in generic diversity composition across islands, whereas shallow reefs are similar in between. While a single island could conserve shallow regional biodiversity, mesophotic depths containing the richest diversity require site‐specific measures, suggesting that considering these mesophotic depths in conservation is necessary to maintain regional diversity.
Journal Article
Recent Marine Heatwaves Affect Marine Ecosystems from Plankton to Seabirds in the Northern Gulf of Alaska
2023
Several decades of research and monitoring in the northern Gulf of Alaska (NGA) have revealed climate-related shifts in ocean temperature and salinity. Accompanying these shifts have been changes in the abundance and diversity of species, from single-celled plankton to fish, seabirds, and marine mammals. Research is documenting long-term change in the region and revealing the mechanisms by which recent marine heatwaves affect the ability of higher trophic levels to survive in these waters. Heatwaves in the northern Gulf of Alaska are likely to become longer, more frequent, and more intense, making long-term monitoring of ecosystem changes critical to understanding and predicting effects on valuable commercial fisheries and culturally significant native harvesting. In addition, documentation of change is necessary for projecting regional and global future climate scenarios and for informing climate-related policy decisions.
Journal Article
Modeling aquaculture suitability in a climate change future
by
Costello, Mark
,
Mackintosh, Amy
,
Jueterbock, Alexander
in
Aquaculture
,
Aquaculture products
,
Biodiversity
2023
Aquaculture has become the primary supplier of fish for human consumption, with production increasing every year since 1990 (FAO, 2020). At the same time, up to 89% of the world’s capture fisheries are fully exploited, overexploited, or collapsed. While some fisheries may have increased yields due to climate change in the short term, global fisheries catch is projected to fall by 10% by 2050 (Barange et al., 2014; Ramos Martins et al., 2021). However, the security of aquaculture production will depend on how future climate change affects productive regions as species’ optimal climatic conditions shift poleward (Chaudhary et al., 2021). This makes the forecasting of climate impacts on key aquaculture species a top priority in order to facilitate adaptation of this industry.
Journal Article