scholarly journals Influence of the environmental factors on species diversity and quantitative development of zoobenthos in the Neva Bay

2018 ◽  
Vol 322 (1) ◽  
pp. 50-65
Author(s):  
E.V. Balushkina ◽  
M.S. Golubkov
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Primary Production ◽  
Large Scale ◽  
Structural Characteristics ◽  
Abiotic Factors ◽  
Chlorophyll Concentration ◽  
Benthic Fauna ◽  
Anthropogenic Stress ◽  
Neva Bay

Hydrochemical characteristics, primary production of plankton, taxonomic composition, species richness, species diversity and quantitative characteristics of the benthic fauna of the Neva Bay had been collected and analyzed at the end of July and the very beginning of August 2003–2012 by the method stepwise regression, calculated equations with a free constant. Effects of biotic and abiotic factors on the structural and functional characteristics of benthic communities in the Neva Bay were evaluated using multiregression analysis. Research period had been accompanied by revival of industry of Saint-Petersburg, construction of ports, active navigation, development of Sea facade and completion of the construction of the St. Petersburg Flood Prevention Facility Complex and a large-scale hydrotechnical works: building of a Marine Multifunctional Reloading Complex (MMRC) “Bronka” and approach fairway to it. Results of statistical analysis showed that the number of species and species diversity of bottom animals in the Neva Bay declined with increased primary production and chlorophyll a concentration. Analysis of the factors influencing the values of biomass of benthic animal communities shows that these characteristics increased with growing chlorophyll concentration. During the anthropogenic stress of 2006–2007, the existing links between the structural characteristics of the zoobenthos and the functional biotic characteristics of the Neva Bay were completely destroyed. Restoration period 2008–2012 was accompanied by an increase in the species richness and species diversity of zoobenthos to the level observed before anthropogenic stress.

scholarly journals Testing biodiversity theory using species richness of reef-building corals across a depth gradient

2019 ◽  
Vol 15 (10) ◽  
pp. 20190493 ◽  
Author(s):  
T. Edward Roberts ◽  
Sally A. Keith ◽  
Carsten Rahbek ◽  
Tom C. L. Bridge ◽  
M. Julian Caley ◽  
...  
Keyword(s):  
Species Richness ◽  
Large Scale ◽  
Coral Species ◽  
Environmental Gradients ◽  
Abiotic Factors ◽  
Empirical Support ◽  
Null Model ◽  
Local Scale ◽  
Small Scale ◽  
Energy Availability

Natural environmental gradients encompass systematic variation in abiotic factors that can be exploited to test competing explanations of biodiversity patterns. The species–energy (SE) hypothesis attempts to explain species richness gradients as a function of energy availability. However, limited empirical support for SE is often attributed to idiosyncratic, local-scale processes distorting the underlying SE relationship. Meanwhile, studies are also often confounded by factors such as sampling biases, dispersal boundaries and unclear definitions of energy availability. Here, we used spatially structured observations of 8460 colonies of photo-symbiotic reef-building corals and a null-model to test whether energy can explain observed coral species richness over depth. Species richness was left-skewed, hump-shaped and unrelated to energy availability. While local-scale processes were evident, their influence on species richness was insufficient to reconcile observations with model predictions. Therefore, energy availability, either in isolation or in combination with local deterministic processes, was unable to explain coral species richness across depth. Our results demonstrate that local-scale processes do not necessarily explain deviations in species richness from theoretical models, and that the use of idiosyncratic small-scale factors to explain large-scale ecological patterns requires the utmost caution.

scholarly journals Plant community diversity and composition provide little resistance to Juniperus encroachment

Botany ◽  
2008 ◽  
Vol 86 (12) ◽  
pp. 1416-1426 ◽  
Author(s):  
Amy C. Ganguli ◽  
David M. Engle ◽  
Paul M. Mayer ◽  
Eric C. Hellgren
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Species Composition ◽  
Plant Species ◽  
Plant Community ◽  
Tallgrass Prairie ◽  
Abiotic Factors ◽  
Community Diversity ◽  
Oak Forest ◽  
Old Field

Widespread encroachment of the fire-intolerant species Juniperus virginiana  L. into North American grasslands and savannahs where fire has largely been removed has prompted the need to identify mechanisms driving J. virginiana encroachment. We tested whether encroachment success of J. virginiana is related to plant species diversity and composition across three plant communities. We predicted J. virginiana encroachment success would (i) decrease with increasing diversity, and (ii) J. virginiana encroachment success would be unrelated to species composition. We simulated encroachment by planting J. virginiana seedlings in tallgrass prairie, old-field grassland, and upland oak forest. We used J. virginiana survival and growth as an index of encroachment success and evaluated success as a function of plant community traits (i.e., species richness, species diversity, and species composition). Our results indicated that J. virginiana encroachment success increased with increasing plant richness and diversity. Moreover, growth and survival of J. virginiana seedlings was associated with plant species composition only in the old-field grassland and upland oak forest. These results suggest that greater plant species richness and diversity provide little resistance to J. virginiana encroachment, and the results suggest resource availability and other biotic or abiotic factors are determinants of J. virginiana encroachment success.

scholarly journals Assessment of water quality and state of waterbasins of different types from characteristics of benthic animal communities

2016 ◽  
Vol 320 (3) ◽  
pp. 262-279
Author(s):  
E.V. Balushkina
Keyword(s):  
Water Quality ◽  
Primary Production ◽  
Large Scale ◽  
Structural Parameters ◽  
Benthic Communities ◽  
River Estuary ◽  
Neva River ◽  
Relationship Of ◽  
The Impact ◽  
Neva Bay

Studies on waterbasins of different type have shown the impact of eutrophication and pollution by toxic and organic matter on the structural and functional characteristics of zoobenthos. A major factor determining quantitative development of non-predatory zoobenthos in lakes is, undoubtedly, the level of development of primary producers. Relationship of zoobenthos biomass and primary production is particularly pronounced in shallow lakes. Analysis of relationship of zoobenthos with abiotic and biotic factors in shallow hyperhaline lakes of Crimea has shown that the most significant parameters determining the values of biomass of macrozoobenthos were salinity and primary production, second in significance were oxygen concentration and depth. The changes in structure and quantitative characteristics of benthic communities of the Neva River estuary occur under impact of a complex combination of organic and toxic pollution. For the assessment of water quality and state of ecosystem in the Neva River estuary we used IP' integrated index specially devised by us for water-bodies and watercourses of north-western Russia. It is based on structural parameters of zoobenthic communities and makes it possible to take into consideration pollution with toxic and organic substances. On average the water quality of the Neva Bay judging from IP' values was relatively stable during 1982–2014. It was assessed as “polluted” with exception for abnormality in 2006 (“polluted–dirty”) caused by large-scale dredging work. As a result of stronger pollution, species diversity of benthic animals in the Resort District of the eastern part of the Gulf of Finland is lower than in the Neva Bay.

scholarly journals Benthic polychaete off Tanintharyi Island, Myeik Archipelago

Bionatura ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 1692-1697
Author(s):  
Zarni Ko Ko ◽  
Hnin Pwint Htwe
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Deep Sea ◽  
Benthic Fauna ◽  
Diversity Indices ◽  
Research Vessel ◽  
Species Evenness ◽  
Ecosystem Survey ◽  
Northern Sector

The survey examined shallow to deep-sea benthic data on benthic fauna from the Myanmar coastal region's northern sector. Benthic samples were collected from 17 stations (26-1500m depth) off Taninthayi Island during the Mayanmar ecosystem survey of the R/V Dr. Fridtjof Nansen Research Vessel. Polychaete (25 taxa in total) had a higher proportion than other groups of benthic fauna. The range of species diversity and evenness were insignificantly different, but species richness differed. The highest species diversity, species evenness, and richness were showed in shallow areas (26 m depth). Keywords: Diversity indices, Polychaetes, Taninthayi Island, Myeik Archipelago.

scholarly journals The abundance and diversity of grasshopper communities in relation to elevation and land use in Malang, Indonesia

2020 ◽  
Vol 21 (12) ◽  
Author(s):  
Amin Setyo Leksono ◽  
Bagyo Yanuwiadi ◽  
Aminudin Afandhi ◽  
MOHAMMAD FARHAN ◽  
Anisa Zairina
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Species Diversity ◽  
Altitudinal Gradient ◽  
Landsat Imagery ◽  
Abiotic Factors ◽  
Significant Negative Correlation ◽  
Grasshopper Species ◽  
Species Richness And Diversity ◽  
Abundance And Diversity

Abstract. Leksono AS, Yanuwiadi B, Afandhi A, Farhan M, Zairina A. 2020. The abundance and diversity of grasshopper communities in relation to elevation and land use in Malang, Indonesia. Biodiversitas 21: 5614-5620. Ecological factors include interactions of the community members with numerous biotic and abiotic factors such as temperature, humidity, precipitation, light intensity, and seasonality show an altitudinal gradient. Most grasshopper species play a role as herbivores and are a good source of protein for other animals such as amphibians, small reptiles, birds, and small mammals. This study aimed to analyze variations in the abundance, richness, and diversity of grasshopper species along an altitudinal gradient. This research was conducted in five locations in Malang District, East Java, Indonesia, namely Bantur, Sumber Pujung Lawang, Pujon, and Poncokusumo. Grasshopper sampling was carried out by the sweeping method using an insect net. Sweepings were carried out on four plots with each plot size of 2 x 10 m2. Sampling was conducted four times from June to August 2020. The data were analyzed using the Shannon Wiener index (diversity analysis) and the Bray-Curtis index. The differences between locations were tested by one-way analysis of variance. Land use was analyzed by ArcGIS, using Landsat imagery 8. The abundance of grasshoppers had a significant negative correlation with elevation. That correlation was positive to species richness and diversity of grasshoppers. That with species diversity was significant, while that with species richness was not significant. The greatest abundance of the grasshopper was found in the middle elevation in Lawang (19.39 ± 2.12). In contrast, the highest species richness and diversity were found in the highest elevation in Poncokusumo (richness = 15.75 ± 1.60 and H '= 2.58 ± 0.11). Land use variation was not significant on abundance, species, richness, and diversity of grasshoppers. Interestingly, the high similarity of the grasshopper compositions in low elevation habitats was detected, indicating that land use in the low land area was remarkable. The abundance of grasshopper had a significant positive correlation with temperature but negatively correlated with humidity. There was no significant correlation among species richness, species diversity with temperature and humidity.

scholarly journals Contrasting effects of anthropogenic and natural acidity in streams: a meta-analysis

2008 ◽  
Vol 275 (1639) ◽  
pp. 1143-1148 ◽  
Author(s):  
Zlatko Petrin ◽  
Göran Englund ◽  
Björn Malmqvist
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Water Chemistry ◽  
Large Scale ◽  
Meta Analysis ◽  
Continental Scale ◽  
Small Streams ◽  
Natural Acidity ◽  
Macroinvertebrate Species ◽  
Ecological Functioning

Large-scale human activities including the extensive combustion of fossil fuels have caused acidification of freshwater systems on a continental scale, resulting in reduced species diversity and, in some instances, impaired ecological functioning. In regions where acidity is natural, however, species diversity and functioning seem to be less affected. This contrasting response is likely to have more than one explanation including the possibility of adaptation in organisms exposed to natural acidity over evolutionary time scales and differential toxicity due to dissimilarities in water chemistry other than pH. However, empirical evidence supporting these hypotheses is equivocal. Partly, this is because previous research has mainly been conducted at relatively small geographical scales, and information on ecological functioning in this context is generally scarce. Our goal was to test whether anthropogenic acidity has stronger negative effects on species diversity and ecological functioning than natural acidity. Using a meta-analytic approach based on 60 datasets, we show that macroinvertebrate species richness and the decomposition of leaf litter—an important process in small streams—tend to decrease with increasing acidity across regions and across both the acidity categories. Macroinvertebrate species richness, however, declines three times more rapidly with increasing acidity where it is anthropogenic than where it is natural, in agreement with the adaptation hypothesis and the hypothesis of differences in water chemistry. By contrast, the loss in ecological functioning differs little between the categories, probably because increases in the biomass of taxa remaining at low pH compensate for losses in functionality that would otherwise accompany losses of taxa from acidic systems. This example from freshwater acidification illustrates how natural and anthropogenic stressors can differ markedly in their effects on species diversity and one aspect of ecological functioning.

scholarly journals Generating and testing ecological hypotheses at the pondscape with environmental DNA metabarcoding: a case study on a threatened amphibian

2018 ◽  
Author(s):  
Lynsey R. Harper ◽  
Lori Lawson Handley ◽  
Christoph Hahn ◽  
Neil Boonham ◽  
Helen C. Rees ◽  
...  
Keyword(s):  
Species Richness ◽  
Large Scale ◽  
Gasterosteus Aculeatus ◽  
Abiotic Factors ◽  
Environmental Dna ◽  
Hypothesis Generation ◽  
Vertebrate Species ◽  
Mammal Species ◽  
Negatively Associated ◽  
Fulica Atra

AbstractEnvironmental DNA (eDNA) metabarcoding is revolutionising biodiversity monitoring, but has unrealised potential for ecological hypothesis generation and testing. Here, we validate this potential in a large-scale analysis of vertebrate community data generated by eDNA metabarcoding of 532 UK ponds. We test biotic associations between the threatened great crested newt (Triturus cristatus) and other vertebrates as well as abiotic factors influencing T. cristatus detection at the pondscape. Furthermore, we test the status of T. cristatus as an umbrella species for pond conservation by assessing whether vertebrate species richness is greater in ponds with T. cristatus and higher T. cristatus Habitat Suitability Index (HSI) scores. T. cristatus detection was positively correlated with amphibian and waterfowl species richness. Specifically, T. cristatus was positively associated with smooth newt (Lissotriton vulgaris), common coot (Fulica atra), and common moorhen (Gallinula chloropus), but negatively associated with common toad (Bufo bufo). T. cristatus detection did not significantly decrease as fish species richness increased, but negative associations with common carp (Cyprinus carpio), three-spined stickleback (Gasterosteus aculeatus) and ninespine stickleback (Pungitius pungitius) were identified. T. cristatus detection was negatively correlated with mammal species richness, and T. cristatus was negatively associated with grey squirrel (Sciurus carolinensis). T. cristatus detection was negatively correlated with larger pond area, presence of inflow, and higher percentage of shading, but positively correlated with HSI score, supporting its application to T. cristatus survey. Vertebrate species richness was significantly higher in T. cristatus ponds and broadly increased as T. cristatus HSI scores increased. We reaffirm reported associations (e.g. T. cristatus preference for smaller ponds) but also provide novel insights, including a negative effect of pond inflow on T. cristatus. Our findings demonstrate the prospects of eDNA metabarcoding for ecological hypothesis generation and testing at landscape scale, and dramatic enhancement of freshwater conservation, management, monitoring and research.

scholarly journals A Combination of Biotic and Abiotic Factors and Diversity Determine Productivity in Natural Deciduous Forests

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1450
Author(s):  
Mahmoud Bayat ◽  
Pete Bettinger ◽  
Sahar Heidari ◽  
Seyedeh Kosar Hamidi ◽  
Abolfazl Jaafari
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Species Richness ◽  
Species Diversity ◽  
Tree Species ◽  
Abiotic Factors ◽  
Basal Area ◽  
Forest Productivity ◽  
Tree Species Diversity ◽  
Artificial Neural

The relative importance of different biotic and abiotic variables for estimating forest productivity remains unclear for many forest ecosystems around the world, and it is hypothesized that forest productivity could also be estimated by local biodiversity factors. Using a large dataset from 258 forest monitoring permanent sample plots distributed across uneven-aged and mixed forests in northern Iran, we tested the relationship between tree species diversity and forest productivity and examined whether several factors (solar radiation, topographic wetness index, wind velocity, seasonal air temperature, basal area, tree density, basal area in largest trees) had an effect on productivity. In our study, productivity was defined as the mean annual increment of the stem volume of a forest stand in m3 ha−1 year−1. Plot estimates of tree volume growth were based on averaged plot measurements of volume increment over a 9-year growing period. We investigated relationships between productivity and tree species diversity using parametric models and two artificial neural network models, namely the multilayer perceptron (MLP) and radial basis function networks. The artificial neural network (ANN) of the MLP type had good ability in prediction and estimation of productivity in our forests. With respect to species richness, Model 4, which had 10 inputs, 6 hidden layers and 1 output, had the highest R2 (0.94) and the lowest RMSE (0.75) and was selected as the best species richness predictor model. With respect to forest productivity, MLP Model 2 with 10 inputs, 12 hidden layers and 1 output had R2 and RMSE of 0.34 and 0.42, respectively, representing the best model. Both of these used a logistic function. According to a sensitivity analysis, diversity had significant and positive effects on productivity in species-rich broadleaved forests (approximately 31%), and the effects of biotic and abiotic factors were also important (29% and 40%, respectively). The artificial neural network based on the MLP was found to be superior for modeling productivity–diversity relationships.

scholarly journals Trophic interactions among vertebrate guilds and plants shape global patterns in species diversity

2018 ◽  
Vol 285 (1883) ◽  
pp. 20180949 ◽  
Author(s):  
Jian Zhang ◽  
Hong Qian ◽  
Marco Girardello ◽  
Vincent Pellissier ◽  
Scott E. Nielsen ◽  
...  
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Trophic Interactions ◽  
Large Scale ◽  
Environmental Drivers ◽  
Top Down ◽  
Bottom Up ◽  
Diversity Patterns ◽  
Biodiversity Patterns ◽  
Global Patterns

Trophic interactions play critical roles in structuring biotic communities. Understanding variation in trophic interactions among systems provides important insights into biodiversity maintenance and conservation. However, the relative importance of bottom-up versus top-down trophic processes for broad-scale patterns in biodiversity is poorly understood. Here, we used global datasets on species richness of vascular plants, mammals and breeding birds to evaluate the role of trophic interactions in shaping large-scale diversity patterns. Specifically, we used non-recursive structural equation models to test for top-down and bottom-up forcing of global species diversity patterns among plants and trophic guilds of mammals and birds (carnivores, invertivores and herbivores), while accounting for extrinsic environmental drivers. The results show that trophic linkages emerged as being more important to explaining species richness than extrinsic environmental drivers. In particular, there were strong, positive top-down interactions between mammal herbivores and plants, and moderate to strong bottom-up and/or top-down interactions between herbivores/invertivores and carnivores. Estimated trophic interactions for separate biogeographical regions were consistent with global patterns. Our findings demonstrate that, after accounting for environmental drivers, large-scale species richness patterns in plant and vertebrate taxa consistently support trophic interactions playing a major role in shaping global patterns in biodiversity. Furthermore, these results suggest that top-down forces often play strong complementary roles relative to bottom-up drivers in structuring biodiversity patterns across trophic levels. These findings underscore the importance of integrating trophic forcing mechanisms into studies of biodiversity patterns.

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