Groynes: a factor modifying the occurrence of dragonfly larvae (Odonata) on a large lowland river

2017 ◽  
Vol 68 (9) ◽  
pp. 1653 ◽  
Author(s):  
P. Buczyński ◽  
A. Szlauer-Łukaszewska ◽  
G. Tończyk ◽  
E. Buczyńska
Keyword(s):  
Species Richness ◽  
Endangered Species ◽  
Habitat Heterogeneity ◽  
Negative Influence ◽  
Lowland River ◽  
Oxbow Lakes ◽  
Habitat Conditions ◽  
Regulated Rivers ◽  
Species Richness And Diversity ◽  
Diverse Habitat

The regulation of rivers and their valleys has had a strong, negative influence on the maintenance of their original biota. Nevertheless, some hydro-engineering works conducted along already regulated rivers may be beneficial, creating habitats for endangered species and assemblages. Such works include the construction of groynes. We analysed this effect on the occurrence of dragonfly larvae along middle and lower stretches of the Oder, where groynes were built over a distance of 306km, creating an area of uniform habitat. We demonstrated that the presence of groynes increased not only the abundance of dragonfly larvae, but also the species richness and diversity of these insects. Habitats were recreated for assemblages typical of a river with highly diverse habitat conditions, from typically riverine assemblages to those occurring in oxbow lakes, also endangered by regulations. The fauna along the stretches with groynes was richer and more valuable than that along the stretches without groynes, achieving values approaching those obtained from modelled unregulated rivers. This can be put down to greater habitat heterogeneity and groyne-reduced levels of waves produced by ships. The presence of groynes provides the key to the restoration or stabilisation of the populations of certain species and to renaturalisation processes.

scholarly journals Spatial and temporal variation in small mammal abundance and diversity under protection, pastoralism and agriculture in the Serengeti Ecosystem, Tanzania

2019 ◽  
Author(s):  
Monica T. Shilereyo ◽  
Flora J. Magige ◽  
Joseph O. Ogutu ◽  
Eivin Røskaft
Keyword(s):  
Land Use ◽  
Species Richness ◽  
Small Mammal ◽  
Protected Area ◽  
Habitat Heterogeneity ◽  
Agricultural Landscape ◽  
Spatial And Temporal Variation ◽  
Wet Season ◽  
Serengeti Ecosystem ◽  
Species Richness And Diversity

AbstractLand use is an important factor influencing animal abundance, species richness and diversity in both protected and human-dominated landscapes. Increase in human population and activities intensify changes in habitat structure and hence abundance, species richness and diversity. We investigated the influences of land use and seasonality on small mammal abundance, species richness and diversity in 10 habitat types distributed over protected, agricultural and pastoral landscapes in the Serengeti ecosystem in Tanzania. We used live traps (n = 141) and capture-recapture methods in each of 10 fixed plots distributed across three landscapes for a total of 28,200 trap nights of effort. Trapping was carried out in the wet and dry seasons for two consecutive years (April 2017 to October 2018). Small mammal abundance was higher in the pastoral than in the protected and in the agricultural landscape. Abundance was higher in the dry than the wet season across all the three landscapes. Species richness and diversity were higher in the protected, middling in the agricultural and lowest in the pastoral landscape. The high abundance in the pastoral landscape was due to the numerical dominance of two species, namely A. niloticus in the shrubland and M. natalensis in the cropland habitat, resulting in low species richness and diversity. Abundance was more evenly distributed across all habitats in the protected area due to less disturbance. The low abundance in the agricultural landscape, likely reflects disturbance from cultivation. High species richness and diversity in the protected area indicate high habitat heterogeneity while high species diversity in the agricultural landscape was likely due to high food availability during and soon after harvests. These findings emphasize the importance of protection in maintaining habitat heterogeneity for wildlife. They also reaffirm the need for buffer zones around protected areas to cushion them from intensifying human activities.

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 Species richness and diversity in shrub savanna using ordinary kriging

2016 ◽  
Vol 51 (8) ◽  
pp. 958-966 ◽  
Author(s):  
Anderson Pedro Bernardina Batista ◽  
José Márcio de Mello ◽  
Marcel Régis Raimundo ◽  
Henrique Ferraço Scolforo ◽  
Aliny Aparecida dos Reis ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Species Richness ◽  
Spatial Dependence ◽  
Ordinary Kriging ◽  
Diversity Index ◽  
Spatial Models ◽  
Shannon Diversity Index ◽  
Shannon Diversity ◽  
Species Richness And Diversity ◽  
Number Of Species

Abstract: The objective of this work was to analyze the spatial distribution and the behavior of species richness and diversity in a shrub savanna fragment, in 2003 and 2014, using ordinary kriging, in the state of Minas Gerais, Brazil. In both evaluation years, the measurements were performed in a fragment with 236.85 hectares, in which individual trees were measured and identified across 40 plots (1,000 m2). Species richness was determined by the total number of species in each plot, and diversity by the Shannon diversity index. For the variogram study, spatial models were fitted and selected. Then, ordinary kriging was applied and the spatial distribution of the assessed variables was described. A strong spatial dependence was observed between species richness and diversity by the Shannon diversity index (<25% spatial dependence degree). Areas of low and high species diversity and richness were found in the shrub savanna fragment. Spatial distribution behavior shows relative stability regarding the number of species and the Shannon diversity index in the evaluated years.

FRESHWATER GASTROPODA FROM ARGENTINA: SPECIES RICHNESS, DISTRIBUTION PATTERNS, AND AN EVALUATION OF ENDANGERED SPECIES

Malacologia ◽  
2006 ◽  
Vol 49 (1) ◽  
pp. 189-208 ◽  
Author(s):  
Alejandra Rumi ◽  
Diego E. Gutiérrez Gregoric ◽  
Verónica Núñez ◽  
Inés I. César ◽  
M. Andrea Roche ◽  
...  
Keyword(s):  
Species Richness ◽  
Endangered Species ◽  
Distribution Patterns

scholarly journals Habitat conditions of the endangered species Salix myrtilloides in Eastern Poland

Dendrobiology ◽  
2015 ◽  
Vol 73 ◽  
pp. 55-64 ◽  
Author(s):  
Artur Serafin ◽  
Magdalena Pogorzelec ◽  
Barbara Banach ◽  
Jacek Mielniczuk
Keyword(s):  
Endangered Species ◽  
Habitat Conditions

scholarly journals Is polychaete diversity in the deep sublittoral of an Antarctic fiord related to habitat complexity?

2012 ◽  
Vol 33 (2) ◽  
pp. 181-197 ◽  
Author(s):  
Krzysztof Pabis ◽  
Jacek Siciński
Keyword(s):  
Species Richness ◽  
Habitat Complexity ◽  
Feeding Guilds ◽  
Depth Range ◽  
Soft Bottom ◽  
Admiralty Bay ◽  
Sea Floor ◽  
Species Richness And Diversity ◽  
South Shetlands ◽  
High Species Richness

Is polychaete diversity in the deep sublittoral of an Antarctic fiord related to habitat complexity?Seventy-six species of Polychaeta were found in 19 quantitative samples collected in the deep sublittoral (200-500 m) of Admiralty Bay (South Shetlands). Three assemblages were distinguished by similarity analysis (clustering, nMDS). The soft bottom in depths from 200 to 300m was strongly dominated byMaldane sarsi antarcticaand had very low species richness and diversity. The second assemblage was distinguished in the areas of the sea floor in the same depth range but with aggregations of Ascidiacea and Bryozoa. It was again characterized by high abundance ofMaldane sarsi antarctica, but showed significantly higher species richness and diversity. Diversity of polychaete feeding guilds was also high in these areas. This pattern was probably associated with an increased habitat complexity due to the presence of dense aggregations of large suspension feeders. High species richness and diversity was also noted in the third assemblage, associated with the deepest sublittoral (400-500 m) of Admiralty Bay. This is the area characterized by very stable environmental conditions, where the assemblage was dominated byTharyx cincinnatus, Sternaspissp.,Maldane sarsi antarctica, andAsychis amphiglypta.

Impacts of Prescribed Fire, Glyphosate, and Seeding on Cogongrass, Species Richness, and Species Diversity in Longleaf Pine

2013 ◽  
Vol 6 (4) ◽  
pp. 536-544 ◽  
Author(s):  
Stephen F. Enloe ◽  
Nancy J. Loewenstein ◽  
David W. Held ◽  
Lori Eckhardt ◽  
Dwight K. Lauer
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Prescribed Fire ◽  
Longleaf Pine ◽  
Pine Forests ◽  
Herbaceous Species ◽  
Integrated Strategies ◽  
Species Richness And Diversity ◽  
Herbicide Treatments ◽  
Rhizome Biomass

AbstractCogongrass [Imperata cylindrica (L.) Beauv.] is a warm-season, rhizomatous grass native to southeast Asia that has invaded thousands of hectares in the southeastern United States. Its negative impacts on pine forests have been well documented, and aggressive control is widely recommended. Although repeated herbicide treatments are effective for suppression, integrated strategies of prescribed burning coupled with herbicide treatment and revegetation are lacking in pine systems. In particular, longleaf pine forests, which are typically open, fire-dependent, communities, are highly susceptible to cogongrass, which is a pyrogenic species. To address management goals for cogongrass control and herbaceous restoration in longleaf pine forests better, field studies were conducted in southwestern Alabama from 2010 to 2012. Two longleaf pine forests with near-monotypic stands of cogongrass in the understory were selected for study. Treatments included combinations of winter prescribed fire, spring and fall glyphosate herbicide treatments, and seeding a mix of native, herbaceous species. Data were collected for three growing seasons following study initiation, and included seasonal herbaceous species cover and final cogongrass shoot and rhizome biomass. Species richness and diversity were calculated and analyzed to ascertain treatment effects over the duration of the study. Burning slightly improved cogongrass control with glyphosate, but had no effect on total cover, species richness, or species diversity. Three glyphosate treatments reduced total vegetative cover and nearly eliminated cogongrass cover, shoot, and rhizome biomass. Glyphosate and glyphosate + seeding also increased herbaceous species richness and diversity. However, aboveground productivity in treated plots was significantly lower than productivity in the untreated control, which was almost exclusively cogongrass. These studies indicate that glyphosate and integrated strategies utilizing glyphosate and seeding are very useful for cogongrass management and increasing herbaceous species richness and diversity in longleaf pine.

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