Trends in Ecology & Evolution
reviewRole of scale and environmental factors in regulation of community structure
Abstract
Pattern in ecological communities - the distribution, abundance and diversity of species - depends on a complex interplay between large - and local-scale processes. Large-scale variation in factors such as environmental stress, dispersal or productivity sets the stage for local-scale ecological processes such as predation or competition. Until recently, most research focused on local-scale explanations of community pattern. Current models attempt to integrate the role of individual large-scale factors with local-scale processes. This trend will continue, with increased effort to understand the specific means by which large-scale factors cause variation among communities.
References (40)
- M.I. Moran
J. Exp. Mar. Biol. Ecol.
(1985) - S.M. Louda et al.
Biochem. Syst. Ecol.
(1983) - B.A. Menge et al.
Adv. Ecol. Res.
(1989) - N.G. Hairston et al.
Am. Nat.
(1960) - R.T. Paine
Am. Nat.
(1966) - J.H. Connell
Science
(1978) - S.R. Carpenter et al.
BioScience
(1985) - J.H. Connell
- B.A. Menge et al.
Am. Nat.
(1976) - S.M. Louda
Acta Oecol. Ser. Oecol. Gen.
Am. Nat.
Am. Nat.
Oikos
Oecologia
Am. Nat.
Science
Perspect. Biol. Med.
Am. Nat.
Cited by (394)
Community composition and diversity of land snails along an elevation gradient in the World Natural Heritage Site, Yakushima Island
2024, Global Ecology and ConservationUnderstanding alpine communities that form along elevation gradients is not only a major topic in community ecology but also provides biological conservation insights into recent environmental changes in alpine ecosystems. In this study, we investigated the community composition and diversity of land snails on Yakushima Island, Japan, which has steep mountainous areas and has been designated a World Natural Heritage Site. As a result of the survey, 3689 individuals of 42 species were recorded at 64 sites, and Bayesian hierarchical models were constructed using a species matrix and environmental data from remote sensing. We found that both land surface temperature, which correlated with elevation, and soil moisture index, which uncorrelated with elevation, altered community composition. Furthermore, species diversity was high at low elevations and decreased monotonically with increasing elevation. This diversity was related to the vegetation types. Thus, the results of these analyses imply that the land snail community on Yakushima Island varies along elevation. This study highlights the need to focus on changes in multiple environmental variables from a conservation perspective and the need to pay attention not only to alpine areas, but also to highly diverse low-elevation areas that are not legally designated as conservation areas.
Fine-scale spatial patterns of deep-sea epibenthic fauna in the Laurentian Channel Marine Protected area
2024, Deep-Sea Research Part I: Oceanographic Research PapersEcological processes at local to global scales impact spatial patterns in abundance and distribution of megafauna. Fine-scale patterns have rarely been investigated through explicitly spatial analytical methods in the deep sea and have been assumed random, uniform, or similar to neighbouring areas. We used spatial statistics (Moran's I, Gi*, and local Moran's I) to identify significant megafaunal patterns (0–100s of meters; 8 focal taxa) in the Laurentian Channel Marine Protected Area, based on imagery from a remotely operated vehicle, using 8 parallel transects at each of 7 stations. Our results included 2 spatial scales, station level (0.256 km2) and paired transect level (0.004 km2). We found local areas with significant aggregations (e.g., Pennatula sp. 2 and Hexacorallia (SC.) spp.) and patches extending for ∼7–27 m, and in one case for ∼155 m. Patchiness also existed between neighbouring images (≤10 m apart). Patterns varied among taxa within stations and for the same taxon among transect pairs. Station-level patterns appear to be related to geological factors, such as BPI (bathymetric position index), benthoscape, pockmarks, and slope. We propose that patterns at the transect level were likely caused by biological factors, possibly related to reproduction due to local currents and retention, or community interactions (e.g., competition). Fine-scale patterns should be considered to ensure effective sampling designs when using fine-scale tools (e.g., imagery), and for establishing accurate community metrics (e.g., abundance and diversity). Our study is relevant to future ecological research, linking patterns to processes, as well as monitoring and conservation in deep-sea ecosystems.
Habitat structure shapes temperate reef assemblages across regional environmental gradients
2024, Science of the Total EnvironmentIntertidal artificial habitats are proliferating, but are generally simpler in structure and host lower biodiversity than natural rocky reefs. Eco-engineering aims to enhance the biodiversity of coastal infrastructure, often through physical structural modifications that mimic topographic properties of natural shores. Relationships between biotic assemblages and structural properties of natural and artificial reefs have been extensively studied at sampling scales of up to 1 m2. But evidence that quantified local structural variation has an appreciable influence on biotic assemblages, at a shore-wide scale across regional environmental gradients, is lacking. Here we addressed this knowledge gap with an observational study at 32 natural and artificial intertidal reef sites in Wales, UK. We used multivariate community analysis and permutation tests to examine associations between local physical structure, regional environmental variables and sessile biotic assemblages. A potential influence of local habitat structure on assemblage composition was evident across regional-scale environmental gradients. Compared to natural sites, artificial reefs had lower taxonomic richness, distinct and more variable assemblage composition, and different physical structure. After removing the effect of habitat (natural or artificial), canonical correspondence analysis showed that environmental variables (wave exposure, sea surface temperature and salinity variation), along with two metrics of physical structure (standard deviation in log-transformed detrended roughness and skewness of surface verticality, both at 0.5 m scale), explained 40 % of the variation in assemblage composition among sites. The two structural metrics independently explained 14.5 % of the variation. Associations identified between individual taxa and environmental variables indicated that sites with a higher proportion of horizontal surfaces hosted more canopy macroalgae, which in turn support other algae and invertebrates. Our findings provide evidence to inform scaling-up of structural eco-engineering interventions from experimental contexts to enhance the biodiversity of coastal infrastructure across regional extents.
Physical, biological and anthropogenic drivers of spatial patterns of coral reef fish assemblages at regional and local scales
2023, Science of the Total EnvironmentSpecies abundance, diversity and community assemblage structure are determined by multiple physical, habitat and management drivers that operate across multiple spatial scales. Here we used a multi-scale coral reef monitoring dataset to examine regional and local differences in the abundance, species richness and composition of fish assemblages in no-take marine reserve (NTMR) and fished zones at four island groups in the Great Barrier Reef Marine Park, Australia. We applied boosted regression trees to quantify the influence of 20 potential drivers on the coral reef fish assemblages. Reefs in two locations, Magnetic Island and the Keppel Islands, had distinctive fish assemblages and low species richness, while the Palm and Whitsunday Islands had similar species composition and higher species richness. Overall, our analyses identified several important physical (temperature, wave exposure) and biological (coral, turf, macroalgal and unconsolidated substratum cover) drivers of inshore reef fish communities, some of which are being altered by human activities. Of these, sea surface temperature (SST) was more influential at large scales, while wave exposure was important both within and between island groups. Species richness declined with increasing macroalgal cover and exposure to cyclones, and increased with SST. Species composition was most strongly influenced by mean SST and percent cover of macroalgae. There was substantial regional variation in the local drivers of spatial patterns. Although NTMR zoning influenced total fish density in some regions, it had negligible effects on fish species richness, composition and trophic structure because of the relatively small number of species targeted by the fishery. These findings show that inshore reef fishes are directly influenced by disturbances typical of the nearshore Great Barrier Reef, highlighting the need to complement global action on climate change with more targeted localised efforts to maintain or improve the condition of coral reef habitats.
Lethal and sublethal implications of low temperature exposure for three intertidal predators
2023, Journal of Thermal BiologyBenthic invertebrate predators play a key role in top-down trophic regulation in intertidal ecosystems. While the physiological and ecological consequences of predator exposure to high temperatures during summer low tides are increasingly well-studied, the effects of cold exposure during winter low tides remain poorly understood. To address this knowledge gap, we measured the supercooling points, survival, and feeding rates of three intertidal predator species in British Columbia, Canada — the sea stars Pisaster ochraceus and Evasterias troschelii and the dogwhelk Nucella lamellosa — in response to exposure to sub-zero air temperatures. Overall, we found that all three predators exhibited evidence of internal freezing at relatively mild sub-zero temperatures, with sea stars exhibiting an average supercooling point of −2.50 °C, and the dogwhelk averaging approximately −3.99 °C. None of the tested species are strongly freeze tolerant, as evidenced by moderate-to-low survival rates after exposure to −8 °C air. All three predators exhibited significantly reduced feeding rates over a two-week period following a single 3-h sublethal (−0.5 °C) exposure event. We also quantified variation in predator body temperature among thermal microhabitats during winter low tides. Predators that were found at the base of large boulders, on the sediment, and within crevices had higher body temperatures during winter low tides, as compared to those situated in other microhabitats. However, we did not find evidence of behavioural thermoregulation via selective microhabitat use during cold weather. Since these intertidal predators are less freeze tolerant than their preferred prey, winter low temperature exposures can have important implications for organism survival and predator-prey dynamics across thermal gradients at both local (habitat-driven) and geographic (climate-driven) scales.
Wetland monitoring: Understanding variability and change in ecological condition
2023, Ramsar Wetlands: Values, Assessment, ManagementWetlands provide crucial benefits to humans so that monitoring their ecological status is key for ensuring the continuity of these benefits. Wetland monitoring, inventory, assessment, and surveillance inform wetland management practices and policies. Therefore, effective wetland management requires effective and continuous wetland monitoring based on hypotheses emerged from inventory and assessment. Wetlands change over space and time due to natural variability and human impacts, such as overexploitation of land and water resources, habitat fragmentation, water diversion, and invasive species. Contemporary ecology, palaeoecology, and remote sensing all contribute to wetland monitoring of ecological character and to the identification of baselines of historical, ‘natural’ conditions. This chapter summarises how physical and biological wetland components are monitored and discusses the processes of wetland monitoring, inventory, assessment, and surveillance and associated opportunities and challenges in the context of the Ramsar Convention and broad scientific and management efforts.