Peeling the Layers of Caddisfly Diversity on a Longitudinal Gradient in Karst Freshwater Habitats Reveals Community Dynamics and Stability

Freshwater biodiversity is facing a severe crisis due to many human impacts, yet the diversity dynamics of freshwater communities and possibilities of assessing these are vastly unexplored. We aimed at emphasizing different aspects of portraying diversity of a species-rich, aquatic insect group (caddisflies; Trichoptera) across four different habitats in an anthropogenically unimpacted, connected karst barrage lake/riverine system. To define diversity, we used common indices with pre-set sensitivity to species abundance/dominance; i.e., sensitivity parameter (species richness, Shannon, Simpson, Berger-Parker) and diversity profiles based on continuous gradients of this sensitivity parameter: the naïve and non-naïve diversity profiles developed by Leinster and Cobbold. The non-naïve diversity profiles show diversity profiles with regard to the similarity among species in terms of ecological traits and preferences, whereas the naïve diversity profile is called mathematically “naïve” as it assumes absolute dissimilarity between species that is almost never true. The commonly used indices and the naïve diversity profile both ranked the springs as least diverse and tufa barriers as most diverse. The non-naïve diversity profiles based on similarity matrices (using feeding behavior and stream zonation preferences of species), showed even greater differences between these habitats, while ranking stream habitats close together, regardless of their longitudinal position. We constructed the Climate Score index (CSI) in order to assess how diversity and species’ vulnerability project the community’s resistance and/or resilience to climate change. The CSI ranked the springs as most vulnerable, followed by all habitats longitudinally placed below them. We highlight the importance of integrating ecological information into biodiversity and vulnerability assessment of freshwater communities.

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Assessing the Benefits of Forested Riparian Zones: A Qualitative Index of Riparian Integrity Is Positively Associated with Ecological Status in European Streams

Water ◽

10.3390/w12041178 ◽

2020 ◽

Vol 12 (4) ◽

pp. 1178 ◽

Cited By ~ 8

Author(s):

Francis J. Burdon ◽

Ellinor Ramberg ◽

Jasmina Sargac ◽

Marie Anne Eurie Forio ◽

Nancy de Saeyer ◽

...

Keyword(s):

Human Impacts ◽

Ecological Status ◽

Riparian Buffers ◽

Average Score ◽

Land Use Impacts ◽

Freshwater Biodiversity ◽

Functional Relationships ◽

Wide Range ◽

Qualitative Index

Developing a general, predictive understanding of ecological systems requires knowing how much structural and functional relationships can cross scales and contexts. Here, we introduce the CROSSLINK project that investigates the role of forested riparian buffers in modified European landscapes by measuring a wide range of ecosystem attributes in stream-riparian networks. CROSSLINK involves replicated field measurements in four case-study basins with varying levels of human development: Norway (Oslo Fjord), Sweden (Lake Mälaren), Belgium (Zwalm River), and Romania (Argeş River). Nested within these case-study basins include multiple, independent stream-site pairs with a forested riparian buffer and unbuffered section located upstream, as well as headwater and downstream sites to show cumulative land-use impacts. CROSSLINK applies existing and bespoke methods to describe habitat conditions, biodiversity, and ecosystem functioning in aquatic and terrestrial habitats. Here, we summarize the approaches used, detail protocols in supplementary materials, and explain how data is applied in an optimization framework to better manage tradeoffs in multifunctional landscapes. We then present results demonstrating the range of riparian conditions present in our case-study basins and how these environmental states influence stream ecological integrity with the commonly used macroinvertebrate Average Score Per Taxon (ASPT) index. We demonstrate that a qualitative index of riparian integrity can be positively associated with stream ecological status. This introduction to the CROSSLINK project shows the potential for our replicated study with its panoply of ecosystem attributes to help guide management decisions regarding the use of forested riparian buffers in human-impacted landscapes. This knowledge is highly relevant in a time of rapid environmental change where freshwater biodiversity is increasingly under pressure from a range of human impacts that include habitat loss, pollution, and climate change.

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Canopy tree growth responses following selection harvest in seven species varying in shade tolerance

Canadian Journal of Forest Research ◽

10.1139/x08-186 ◽

2009 ◽

Vol 39 (2) ◽

pp. 430-440 ◽

Cited By ~ 26

Author(s):

Trevor A. Jones ◽

Grant M. Domke ◽

Sean C. Thomas

Keyword(s):

Community Dynamics ◽

Time Lag ◽

Species Abundance ◽

Basal Area ◽

Maximum Growth ◽

Forest Community ◽

Growth Responses ◽

Canopy Tree ◽

Tolerant Species ◽

Shade Tolerant Species

We used tree ring measurements to investigate the temporal response of basal area increment (BAI) of canopy trees following selection harvests by sampling across a chronosequence of stands with known harvest dates in tolerant hardwood (Great Lakes – St. Lawrence) stands in central Ontario. Seven tree species of various shade tolerances ranged widely in their responses to reduced competition. The more shade-tolerant species responded more positively: shade-tolerant species showed an average increase in BAI of 35% 4–15 years postharvest compared with 16% for mid-tolerant species and –7.5% for intolerant species. All species showed a time-lag in postharvest growth responses, with maximum growth responses occurring between 3 and 15 years postharvest. Tree size was the most important factor determining the magnitude of BAI response, with smaller trees consistently responding more than larger trees. We suggest that higher growth responses to selection harvests among shade-tolerant species may contribute to declines in mid-tolerant species abundance in selection-managed stands. More broadly, interspecific variability in canopy tree responses to forest disturbance appears to follow patterns distinct from seedling and sapling responses, with important implications to forest community dynamics in both managed and unmanaged forests.

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Vascular plant community dynamics following hexazinone site preparation in the lower Coastal Plain

Canadian Journal of Forest Research ◽

10.1139/x93-275 ◽

1993 ◽

Vol 23 (10) ◽

pp. 2216-2229 ◽

Cited By ~ 14

Author(s):

R. Neal Wilkins ◽

Wayne R. Marion ◽

Daniel G. Neary ◽

George W. Tanner

Keyword(s):

Plant Community ◽

Community Dynamics ◽

Vascular Plant ◽

Species Abundance ◽

Woody Species ◽

Application Rate ◽

Site Preparation ◽

Herbaceous Vegetation ◽

Growing Seasons ◽

Species Abundance Distributions

Differential responses of vascular plant community compositions, diversities, and species-abundance distributions to hexazinone site preparation were evaluated on three 1-year-old clearcuts, each representing a point along a generalized edaphic gradient (xeric sandhill, mesic flatwoods, and hydric hammock). Foliar cover by species was sampled along four 20-m permanent line transects within each of three blocked replications of hexazinone treatments (0.0, 1.7, 3.4, and 6.8 kg/ha) at pretreatment and after the first and second growing seasons post-treatment. Cover by woody species decreased with increasing hexazinone rates on all sites (P < 0.05). Herbaceous vegetation recovered from first-season reductions to levels that did not vary with treatment (xeric sandhill and mesic flatwoods) or increased with increasing hexazinone rates (hydric hammock). Hexazinone tolerance by Gelsemiumsempervirens (L.) Ait.f. and Vaccinium spp. on the xeric sandhill and Ilexglabra (L.) Gray and G. sempervirens on the mesic flatwoods influenced diversity responses by woody and herbaceous vegetation. With increasing rates, herbaceous diversity decreased on the xeric sandhill, did not vary on the mesic flatwoods, and increased on the hydric hammock. Plant community responses to hexazinone were found to be functions of application rate, edaphic factors, adaptive strategies of resident species, and the presence or absence of hexazinone-tolerant species.

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Seasonal temporal dynamics of marine protists communities in tidally mixed coastal waters

10.1101/2021.09.15.460302 ◽

2021 ◽

Author(s):

Mariarita Caracciolo ◽

Fabienne Rigaut-Jalabert ◽

Sarah Romac ◽

Frédéric Mahé ◽

Samuel Forsans ◽

...

Keyword(s):

Community Dynamics ◽

Temporal Dynamics ◽

Seasonal Pattern ◽

Temporal Structure ◽

Species Abundance ◽

Temporal Correlation ◽

Tidal Mixing ◽

Taxonomic Resolution ◽

English Channel ◽

Turnover Rates

AbstractMajor seasonal community reorganizations and associated biomass variations are landmarks of plankton ecology. However, the processes determining marine species and community turnover rates have not been fully elucidated so far. Here, we analyse patterns of planktonic protist community succession in temperate latitudes, based on quantitative taxonomic data from both microscopy counts and ribosomal DNA metabarcoding from plankton samples collected biweekly over 8 years (2009-2016) at the SOMLIT-Astan station (Roscoff, Western English Channel). Considering the temporal structure of community dynamics (creating temporal correlation), we elucidated the recurrent seasonal pattern of the dominant species and OTUs (rDNA-derived taxa) that drive annual plankton successions. The use of morphological and molecular analyses in combination allowed us to assess absolute species abundance while improving taxonomic resolution, and revealed a greater diversity. Overall, our results underpinned a protist community characterised by a seasonal structure, which is supported by the dominant OTUs. We detected that some were partly benthic as a result of the intense tidal mixing typical of the French coasts in the English Channel. While the occurrence of these microorganisms is driven by the physical and biogeochemical conditions of the environment, internal community processes, such as the complex network of biotic interactions, also play a key role in shaping protist communities.

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Monitoring of adult aquatic insect activities and ecological role in the riparian zone of streams in the Western Ghats, India

IRA-International Journal of Applied Sciences (ISSN 2455-4499) ◽

10.21013/jas.v4.n3.p10 ◽

2016 ◽

Vol 4 (3) ◽

pp. 460

Author(s):

T. Kubendran ◽

M. Ramesh

Keyword(s):

Aquatic Insects ◽

Western Ghats ◽

Riparian Zone ◽

Food Resource ◽

Aquatic Insect ◽

Ecological Role ◽

Freshwater Biodiversity ◽

The Western Ghats ◽

Adult Aquatic Insects

<div>The Western Ghats, running parallel to the west coast of India between 8° N and 21° N is a prominent feature of the peninsular India. In freshwater biodiversity hotspots like the Western Ghats, no information is available on activates and ecological role of adult aquatic insect in the riparian zone of streams. Most adult aquatic insects that emerge from streams live briefly in the nearby riparian zone. Adult activities, such as mating dispersal and feeding influence their distribution in the terrestrial habitat. An observation at Kurangani streams, Western Ghats, India has shown that both numbers and biomass of adult aquatic insects are greatest in the near stream vegetation; however, adult insects can be relatively common 1 to 10 feet from the stream. Why because, adult aquatic insects are abundant and they are primary food resource for many riparian insectivores. The role of adult aquatic insects in the riparian zone must be better understood for riparian and aquatic food chain to be complete. </div>

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Disentangling metacommunity processes using multiple metrics in space and time

10.1101/2020.10.29.361303 ◽

2020 ◽

Author(s):

Laura Melissa Guzman ◽

Patrick L. Thompson ◽

Duarte S Viana ◽

Bram Vanschoenwinkel ◽

Zsófia Horváth ◽

...

Keyword(s):

Community Structure ◽

Community Dynamics ◽

Variation Partitioning ◽

Species Abundance ◽

Emergent Properties ◽

Sampling Effort ◽

Summary Statistics ◽

Space And Time ◽

Metacommunity Dynamics ◽

Analytical Approaches

AbstractMetacommunity ecology has focused on using observational and analytical approaches to disentangle the role of critical assembly processes, such as dispersal limitation and environmental filtering. Many methods have been proposed for this purpose, most notably multivariate analyses of species abundance and its association with variation in spatial and environmental conditions. These approaches tend to focus on few emergent properties of metacommunities and have largely ignored temporal community dynamics. By doing so, these are limited in their ability to differentiate metacommunity dynamics. Here, we develop a Virtual ecologist’ approach to evaluate critical metacommunity assembly processes based on a number of summary statistics of community structure across space and time. Specifically, we first simulate metacommunities emphasizing three main processes that underlie metacommunity dynamics (density-independent responses to abiotic conditions, density-dependent biotic interactions, and dispersal). We then calculate a number of commonly used summary statistics of community structure in space and time, and use random forests to evaluate their utility for understanding the strength of these three processes. We found that: (i) time series are necessary to disentangle metacommunity processes, (ii) each of the three studied processes is distinguished with different descriptors, (iii) each summary statistic is differently sensitive to temporal and spatial sampling effort. Some of the most useful statistics include the coefficient of variation of abundances through time and metrics that incorporate variation in the relative abundances (evenness) of species. Surprisingly, we found that when we only used a single snapshot of community variation in space, the most commonly used approaches based on variation partitioning were largely uninformative regarding assembly processes, particularly, variation in dispersal. We conclude that a combination of methods and summary statistics will be necessary to understand the processes that underlie metacommunity assembly through space and time.

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Towards a unification of niche and neutral models of community ecology

10.1101/273664 ◽

2018 ◽

Author(s):

Andres Laan ◽

Gonzalo G. de Polavieja

Keyword(s):

Population Dynamics ◽

Large Scale ◽

Community Dynamics ◽

Neutral Theory ◽

Species Abundance ◽

Theory Model ◽

Niche Theory ◽

Species Abundance Distributions ◽

Restoring Forces ◽

Neutral Models

AbstractEcological models of community dynamics fall into two main categories. The neutral theory of biodiversity correctly predicts various large-scale ecosystem characteristics such as the species abundance distributions. On a smaller scale, the niche theory of species competition explains population dynamics and interactions between two to a dozen species. Despite the successes of the two theories, they rely on two contradictory assumptions. In the neutral theory each species is competitively equivalent while in the niche theory every species is specialized to exploit a specific part of its environment. Here we propose a resolution to this contradiction using a game theory model of competition with an attractor hyperplane as its equilibrium solution. When the population dynamics shifts within the hyperplane, it is selectively neutral. However, any movement perpendicular to the hyperplane is subject to restoring forces similar to what is predicted by the niche theory. We show that this model correctly reproduces empirical species abundance distributions and is also compatible with species removal experiments.

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The Dynamic Hypercube as a Niche Community Model

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.686403 ◽

2021 ◽

Vol 9 ◽

Author(s):

John M. Halley ◽

Stuart L. Pimm

Keyword(s):

Community Dynamics ◽

Neutral Theory ◽

Species Abundance ◽

Ecological Communities ◽

Evolutionary Time ◽

Community Model ◽

Theory Of Island Biogeography ◽

Species Abundance Distributions ◽

Hypercube Model ◽

Zero Sum

Different models of community dynamics, such as the MacArthur–Wilson theory of island biogeography and Hubbell’s neutral theory, have given us useful insights into the workings of ecological communities. Here, we develop the niche-hypervolume concept of the community into a powerful model of community dynamics. We describe the community’s size through the volume of the hypercube and the dynamics of the populations in it through the fluctuations of the axes of the niche hypercube on different timescales. While the community’s size remains constant, the relative volumes of the niches within it change continuously, thus allowing the populations of different species to rise and fall in a zero-sum fashion. This dynamic hypercube model reproduces several key patterns in communities: lognormal species abundance distributions, 1/f-noise population abundance, multiscale patterns of extinction debt and logarithmic species-time curves. It also provides a powerful framework to explore significant ideas in ecology, such as the drift of ecological communities into evolutionary time.

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Crustacean communities in coastal ephemeral pools in the Araucanía region (38° S, Chile)

Brazilian Journal of Biology ◽

10.1590/1519-6984.21714 ◽

2016 ◽

Vol 76 (4) ◽

pp. 811-817 ◽

Cited By ~ 4

Author(s):

P. De los Ríos-Escalante ◽

P. Acevedo

Keyword(s):

Community Structure ◽

Community Dynamics ◽

Species Abundance ◽

Null Model ◽

Total Dissolved Solids ◽

Second Step ◽

Dissolved Solids ◽

Temperature Conductivity ◽

Ephemeral Pools ◽

Total Data

Abstract The fauna communities of ephemeral pools in southern Chile are characterized by heterogeneity of crustacean taxa; nevertheless, no detailed studies exist of their community structure. The aim of the present study was to analyze the crustacean community structure in two groups of ephemeral pools (Puaucho and Nigue pools) in the coastal zone of the Araucanía region. A correlation matrix was made by species abundance against temperature, conductivity, pH and total dissolved solids. In a second step, a null model for species co-occurrence was applied to the total data and to each group. The results for total data revealed a significant direct relation between the abundance of H. costera, C. dubia and Mesocyclops. For the Puaucho pools, the same results were found together with direct associations with total dissolved solids, conductivity and pH. Finally, different results were found for the Nigue pools, with no clear significant associations, either direct or indirect, between the abundance of different crustacean taxa and abiotic parameters. These results were supported by the co-occurrence null model analysis, which revealed the presence of regulator factors for the total data, and for each of the two groups. Ecological topics are discussed with emphasis on meta-community dynamics.

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Laws of diversity and variation in microbial communities

10.1101/680454 ◽

2019 ◽

Author(s):

Jacopo Grilli

Keyword(s):

Microbial Communities ◽

Community Dynamics ◽

Microbial Community Composition ◽

Species Abundance ◽

Random Processes ◽

Environmental Stochasticity ◽

Mechanistic Models ◽

Controversial Issues ◽

Ecological Communities ◽

Quantitative Understanding

How coexistence of many species is maintained is a fundamental and unanswered question in ecology. Coexistence is a puzzle because we lack a quantitative understanding of the variation in species presence and abundance. Whether variation in ecological communities is driven by deterministic or random processes is one of the most controversial issues in ecology. Here, we study the variation of species presence and abundance in microbial communities from a macroecological standpoint. We identify three novel, fundamental, and universal macroecological laws that characterize the fluctuation of species abundance across communities and over time. These three laws — in addition to predicting the presence and absence of species, diversity and other commonly studied macroecological patterns — allow to test mechanistic models and general theories aiming at describing the fundamental processes shaping microbial community composition and dynamics. We show that a mathematical model based on environmental stochasticity quantitatively predicts the three macroecological laws, as well as non-stationary properties of community dynamics.

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