Impact of nutrient enrichment on habitat heterogeneity and species richness of aquatic macrophytes: evidence from freshwater tropical lakes of Central Ganga Plain, India

2021 ◽  
Author(s):  
D. Dubey ◽  
S. Kumar ◽  
V. Dutta
Keyword(s):  
Species Richness ◽  
Nutrient Enrichment ◽  
Habitat Heterogeneity ◽  
Aquatic Macrophytes ◽  
Tropical Lakes ◽  
Ganga Plain

scholarly journals Modelling avian biodiversity using raw, unclassified satellite imagery

2014 ◽  
Vol 369 (1643) ◽  
pp. 20130197 ◽  
Author(s):  
Véronique St-Louis ◽  
Anna M. Pidgeon ◽  
Tobias Kuemmerle ◽  
Ruth Sonnenschein ◽  
Volker C. Radeloff ◽  
...  
Keyword(s):  
Species Richness ◽  
Habitat Heterogeneity ◽  
Bird Species ◽  
Image Texture ◽  
Spectral Mixture Analysis ◽  
Mixture Analysis ◽  
Bird Species Richness ◽  
Habitat Composition ◽  
Avian Biodiversity ◽  
Spectral Mixture

Applications of remote sensing for biodiversity conservation typically rely on image classifications that do not capture variability within coarse land cover classes. Here, we compare two measures derived from unclassified remotely sensed data, a measure of habitat heterogeneity and a measure of habitat composition, for explaining bird species richness and the spatial distribution of 10 species in a semi-arid landscape of New Mexico. We surveyed bird abundance from 1996 to 1998 at 42 plots located in the McGregor Range of Fort Bliss Army Reserve. Normalized Difference Vegetation Index values of two May 1997 Landsat scenes were the basis for among-pixel habitat heterogeneity (image texture), and we used the raw imagery to decompose each pixel into different habitat components (spectral mixture analysis). We used model averaging to relate measures of avian biodiversity to measures of image texture and spectral mixture analysis fractions. Measures of habitat heterogeneity, particularly angular second moment and standard deviation, provide higher explanatory power for bird species richness and the abundance of most species than measures of habitat composition. Using image texture, alone or in combination with other classified imagery-based approaches, for monitoring statuses and trends in biological diversity can greatly improve conservation efforts and habitat management.

scholarly journals Aquatic macrophyte community varies in urban reservoirs with different degrees of eutrophication

2014 ◽  
Vol 26 (2) ◽  
pp. 129-142 ◽  
Author(s):  
Suelen Cristina Alves da Silva ◽  
Armando Carlos Cervi ◽  
Cleusa Bona ◽  
André Andrian Padial
Keyword(s):  
Species Richness ◽  
Temporal Variation ◽  
Indicator Species ◽  
Beta Diversity ◽  
Aquatic Macrophytes ◽  
Aquatic Macrophyte ◽  
Wiener Index ◽  
Spatial And Temporal Variation ◽  
Macrophyte Community ◽  
Aquatic Macrophyte Community

AIM: Investigate spatial and temporal variation in the aquatic macrophyte community in four urban reservoirs located in Curitiba metropolitan region, Brazil. We tested the hypothesis that aquatic macrophyte community differ among reservoirs with different degrees of eutrophication. METHODS: The reservoirs selected ranged from oligotrophic/mesotrophic to eutrophic. Sampling occurred in October 2011, January 2012 and June 2012. Twelve aquatic macrophytes stands were sampled at each reservoir. Species were identified and the relative abundance of aquatic macrophytes was estimated. Differences among reservoirs and over sampling periods were analyzed: i) through two‑way ANOVAs considering the stand extent (m) and the stand biodiversity - species richness, evenness, Shannon-Wiener index and beta diversity (species variation along the aquatic macrophyte stand); and ii) through PERMANOVA considering species composition. Indicator species that were characteristic for each reservoir were also identified. RESULTS: The aquatic macrophyte stand extent varied among reservoirs and over sampling periods. Species richness showed only temporal variation. On the other hand, evenness and Shannon-Wiener index varied only among reservoirs. The beta diversity of macrophyte stands did not vary among reservoirs or over time, meaning that species variability among aquatic macrophyte stands was independent of the stand extent and reservoir eutrophication. Community composition depended on the reservoir and sampling period. CONCLUSIONS: Our results support our initial expectation that reservoirs of different degrees of eutrophication have different aquatic macrophyte communities. As a consequence, each reservoir had particular indicator species. Therefore, monitoring and management efforts must be offered for each reservoir individually.

scholarly journals An assessment of the factors determining rotifer assemblage in river-lake systems: the effects of seasonality and habitat

2019 ◽  
Vol 36 ◽  
pp. 1-5
Author(s):  
Moacyr Serafim-Júnior ◽  
Gilmar Perbiche-Neves ◽  
Fabio Lansac-Toha
Keyword(s):  
Species Richness ◽  
Aquatic Macrophytes ◽  
Hydrological Cycle ◽  
High Water ◽  
Water Levels ◽  
Natural Environments ◽  
Ecological Attributes ◽  
Lake System ◽  
The Mean ◽  
Lake Systems

Zooplankton exhibit several trends of variation in space and time, and these trends can be more evident in natural environments without anthropic perturbations. Examples of anthropic factors are climate change, eutrophication and construction of reservoirs. This study evaluated the influence of three factors – seasonality, type of environment and the presence of aquatic macrophytes – on various ecological attributes of rotifers in a river-lake system located in the Paraná River floodplain. Monthly samplings were conducted during 1993 and 1994. The mean species richness per sample was 60 species. The seasonality and the type of environment influenced the ecological attributes of rotifer assemblages, while the presence or absence of aquatic macrophytes did not. Species richness was highest in the lake system and during the months when water levels were low. Multivariate analysis indicates a small group of species associated with the low water-level phase. In contrast, many species were associated with high water levels or increasing water levels. The seasonal variation of hydrological cycle and the type of environment are the most important factors for rotifer structure in natural conditions.

Guild-specific responses of avian species richness to LiDAR-derived habitat heterogeneity

2014 ◽  
Vol 59 ◽  
pp. 72-83 ◽  
Author(s):  
Peter J. Weisberg ◽  
Thomas E. Dilts ◽  
Miles E. Becker ◽  
Jock S. Young ◽  
Diane C. Wong-Kone ◽  
...  
Keyword(s):  
Species Richness ◽  
Habitat Heterogeneity ◽  
Avian Species

scholarly journals Changes in small mammal assemblage structure across a rain forest/open forest ecotone

1998 ◽  
Vol 14 (2) ◽  
pp. 187-198 ◽  
Author(s):  
STEPHEN E. WILLIAMS ◽  
HELENE MARSH
Keyword(s):  
Species Richness ◽  
Small Mammal ◽  
Rain Forest ◽  
Habitat Heterogeneity ◽  
Large Change ◽  
Open Forest ◽  
Live Trapping ◽  
Sclerophyll Forest ◽  
World Heritage Area ◽  
Forest Ecotone

The effect of the change in vegetation structure from closed rain forest to tall open forest on the small mammal assemblage was studied by live trapping at three sites where the ecotone was very narrow (> 20 m) near the southern end of the Wet Tropics World Heritage Area of Australia. Habitat heterogeneity was significantly higher in the mixed open forest/ecotone area than in the adjacent rain forest. There was a large change in the struture of the small mammal assemblage coincident with the vegetation discontinuity. Although the species richness of small mammals was relatively constant across the gradient, the evenness and diversity of the assemblage declined across the transition from open forest into rain forest and biomass increased, largely due to the high abundance of Rattus fuscipes in the rain forest. The results suggest that the species richness of the small mammal assemblage was not determined by the spatial heterogeneity of the vegetation struture. The species composition of the rain forest is probably related to the historical biogeography of the area whereas the species richness of the wet sclerophyll forest is probably due to a mass-area effect from the adjcant large areas of rain forest and dry sclerophyll forest. However, the evenness, and therefore the diversity of the assemblage, was strongly affected by habitat heterogeneity.

scholarly journals Food plant diversity as broad-scale determinant of avian frugivore richness

2007 ◽  
Vol 274 (1611) ◽  
pp. 799-808 ◽  
Author(s):  
W. Daniel Kissling ◽  
Carsten Rahbek ◽  
Katrin Böhning-Gaese
Keyword(s):  
Species Richness ◽  
Habitat Heterogeneity ◽  
Spatial Scales ◽  
Fruit Size ◽  
Food Plant ◽  
Sub Saharan Africa ◽  
Food Plants ◽  
Close Relationship ◽  
Avian Frugivores ◽  
Sub Saharan

The causes of variation in animal species richness at large spatial scales are intensively debated. Here, we examine whether the diversity of food plants, contemporary climate and energy, or habitat heterogeneity determine species richness patterns of avian frugivores across sub-Saharan Africa. Path models indicate that species richness of Ficus (their fruits being one of the major food resources for frugivores in the tropics) has the strongest direct effect on richness of avian frugivores, whereas the influences of variables related to water–energy and habitat heterogeneity are mainly indirect. The importance of Ficus richness for richness of avian frugivores diminishes with decreasing specialization of birds on fruit eating, but is retained when accounting for spatial autocorrelation. We suggest that a positive relationship between food plant and frugivore species richness could result from niche assembly mechanisms (e.g. coevolutionary adaptations to fruit size, fruit colour or vertical stratification of fruit presentation) or, alternatively, from stochastic speciation–extinction processes. In any case, the close relationship between species richness of Ficus and avian frugivores suggests that figs are keystone resources for animal consumers, even at continental scales.

scholarly journals Discovery of widely available abyssal rock patches reveals overlooked habitat type and prompts rethinking deep-sea biodiversity

2020 ◽  
Vol 117 (27) ◽  
pp. 15450-15459 ◽  
Author(s):  
Torben Riehl ◽  
Anne-Cathrin Wölfl ◽  
Nico Augustin ◽  
Colin W. Devey ◽  
Angelika Brandt
Keyword(s):  
Species Richness ◽  
Deep Sea ◽  
Habitat Heterogeneity ◽  
Habitat Type ◽  
Substrate Availability ◽  
Fracture Zones ◽  
Geographic Patterns ◽  
Faunal Diversity ◽  
Sediment Variability ◽  
Seafloor Sediment

Habitat heterogeneity and species diversity are often linked. On the deep seafloor, sediment variability and hard-substrate availability influence geographic patterns of species richness and turnover. The assumption of a generally homogeneous, sedimented abyssal seafloor is at odds with the fact that the faunal diversity in some abyssal regions exceeds that of shallow-water environments. Here we show, using a ground-truthed analysis of multibeam sonar data, that the deep seafloor may be much rockier than previously assumed. A combination of bathymetry data, ruggedness, and backscatter from a trans-Atlantic corridor along the Vema Fracture Zone, covering crustal ages from 0 to 100 Ma, show rock exposures occurring at all crustal ages. Extrapolating to the whole Atlantic, over 260,000 km2of rock habitats potentially occur along Atlantic fracture zones alone, significantly increasing our knowledge about abyssal habitat heterogeneity. This implies that sampling campaigns need to be considerably more sophisticated than at present to capture the full deep-sea habitat heterogeneity and biodiversity.

scholarly journals The value of local habitat heterogeneity and productivity when estimating avian species richness and species of concern

Ecosphere ◽  
2020 ◽  
Vol 11 (5) ◽  
Author(s):  
W. Justin Cooper ◽  
William J. McShea ◽  
Tavis Forrester ◽  
David A. Luther
Keyword(s):  
Species Richness ◽  
Habitat Heterogeneity ◽  
Avian Species ◽  
Local Habitat

Environmental heterogeneity influences life‐form richness and species composition but not species richness of aquatic macrophytes in tropical coastal rivers

2020 ◽  
Vol 65 (11) ◽  
pp. 1894-1905
Author(s):  
Laís Samira Correia Nunes ◽  
Cristiane Akemi Umetsu ◽  
Antonio Fernando Monteiro Camargo
Keyword(s):  
Species Richness ◽  
Species Composition ◽  
Aquatic Macrophytes ◽  
Environmental Heterogeneity ◽  
Life Form ◽  
Coastal Rivers
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