نتایج جستجو برای: richness margalef index

تعداد نتایج: 415206  

Biodiversity is one of the important concepts in ecology and vegetation management, and plays an important role in the health, production, and evaluation of ecosystems. Species diversity is a major part of biodiversity and one of the most important parameters of ecosystem changes. In this research, the data of the rangeland evaluation different climate zones of Isfahan province were used in fiv...

2012
Benjamin F. Leutner Manuel J. Steinbauer Carina M. Müller Andrea J. Früh

Micro-relief heterogeneity can lead to substantial variability in microclimate and hence niche opportunities on a small scale. We explored the relationship between plant species richness and small-scale heterogeneity of micro-relief on the subtropical island of La Palma, Canary Islands. Overall, we sampled 40 plots in laurel and pine forests at four altitudinal bands. Species richness was recor...

Journal: :Revista de biologia tropical 2007
Jorge E Ramírez-Albores

Knowledge of the composition of the bird community in Alto Balsas (southwestern Puebla, Central Mexico) is needed for management programs aiming at protection and conservation of bird species and their habitats I studied sites with tropical deciduous forest. Data were obtained during 1666 hours of field work in 238 days from March 1998 to September 2000. Six permanent transect (3.5 km long and ...

2001

We examined patterns of shrub species diversity relative to landscape-scale variability in environmental factors within two watersheds on the coastal flank of the Santa Ynez Mountains, California. Shrub species richness and dominance was sampled at a hierarchy of spatial units using a highpowered telescope from remote vantage points. Explanatory variables included field estimates of total canop...

2017
Wang Tian Huayong Zhang Lei Zhao Feifan Zhang Hai Huang

The relationship between biodiversity and ecosystem functioning is a central issue in ecology, but how this relationship is affected by nutrient stress is still unknown. In this study, we analyzed the phytoplankton diversity effects on community biomass and stability along nutrient gradients in an artificial eutrophic lake. Four nutrient gradients, varying from slightly eutrophic to highly eutr...

Journal: :Journal of applied science and environmental management 2022

This study was carried out to assess the tree species diversity, family composition and diameter size distribution of in Igbo-Olua sacred groove, Ondo state, Nigeria using appropriate standard techniques. A total 34 distributed 23 families were recorded. Sterculiaceae (66) had highest number individual stem per ha while Moraceae terms hectare (7). The structure is typical natural forest type wi...

2015
Mara Baudena Angel Sánchez Co-Pierre Georg Paloma Ruiz-Benito Miguel Á. Rodríguez Miguel A. Zavala Max Rietkerk

How species richness relates to environmental gradients at large extents is commonly investigated aggregating local site data to coarser grains. However, such relationships often change with the grain of analysis, potentially hiding the local signal. Here we show that a novel network technique, the "method of reflections", could unveil the relationships between species richness and climate with...

Journal: :Journal of Forestry Research 2021

Abstract The positive ecological interaction between gap formation and natural regeneration has been examined but little research carried out on the effects of gaps in forests under different intensities disturbance. This study evaluates composition, diversity, density abundance tree species undisturbed, intermittently disturbed, disturbed forest sites. Bia Tano Forest Reserve Ghana was area th...

Journal: :Ecology 2006
Sunil Kumar Thomas J Stohlgren Geneva W Chong

Spatial heterogeneity may have differential effects on the distribution of native and nonnative plant species richness. We examined the effects of spatial heterogeneity on native and nonnative plant species richness distributions in the central part of Rocky Mountain National Park, Colorado, USA. Spatial heterogeneity around vegetation plots was characterized using landscape metrics, environmen...

2017
Suhaila Ab Hamid Che Salmah Md Rawi

The Ephemeroptera, Plecoptera and Trichoptera (EPT) community structure and the specific sensitivity of certain EPT genera were found to be influenced by water parameters in the rivers of Gunung Jerai Forest Reserve (GJFR) in the north of peninsular Malaysia. The scores of EPT taxa richness of >10 in all rivers indicated all rivers' habitats were non-impacted, having good water quality coincidi...

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