نتایج جستجو برای: mean of richness margalef

تعداد نتایج: 21177290  

2014
Hamed Yazdian Nematollah Jaafarzadeh Banafsheh Zahraie

The ecosystem health of rivers downstream of dams is among the issues that has become focus of attention of many researchers particularly in the recent years. This paper aims to deal with the question, how the environmental health of a river ecosystem can be addressed in water resources planning and management studies. In this study, different parameters affecting the ecosystem of river-reservo...

2017
H. Jimenez E. Keppel A. L. Chang G. M. Ruiz

Whilemany studies of non-native species have examined either soft-bottom or hard-bottom marine communities, including artificial structures at docks andmarinas, formal comparisons across these habitat types are rare. The number of nonindigenous species (NIS) may differ among habitats, due to differences in species delivery (trade history) and susceptibility to invasions. In this study, we quant...

2016
Xiang Xu Huayong Zhang Wang Tian Xiaoqiang Zeng Hai Huang

BACKGROUND Understanding altitudinal patterns of biological diversity and their underlying mechanisms is critically important for biodiversity conservation in mountainous regions. The contribution of area to plant diversity patterns is widely acknowledged and may mask the effects of other determinant factors. In this context, it is important to examine altitudinal patterns of corrected taxon ri...

Journal: :International Journal of Tropical Drylands 2023

Abstract. Pramudita DA, Armando MF, Rahmayani D, Afifah FN, Putri NRA, Hartanti AN, Safira RN, Mahajoeno E, Indrawan M, Nazar IA, Buot Jr IE, Setyawan AD. 2023. Species diversity, richness, and conservation status of Pteridophyta in the karst ecosystem Donorejo Forest, Kaligesing, Purworejo, Indonesia. Intl J Trop Drylands 7: 16-25. is often used as an environmental bioindicator. It can be foun...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شیراز - دانشکده علوم 1392

gol-e-gohar iron ore mine of sirjan in southern part of iran is a large open pit that operates below the groundwater table and during mining operation, dewatering is required to prevent operation processes from flooding. current operation is going on by digging wells in or out of the pit and pumping to prevent flooding. as a result of the former dewatering operation a vast deep cone of depressi...

Journal: :Molecular ecology 2003
L J Weider A Hobaek

As part of a large international Arctic biodiversity expedition (Tundra Northwest '99), we examined the distribution of members of the arctic Daphnia pulex complex (Cladocera, Anomopoda) from 121 tundra ponds, spread across 16 sites spanning a large portion of arctic Canada (i.e. from 62 degrees 22' N to 79 degrees 01' N; 66 degrees 45' W to 139 degrees 37' W). Using allozyme electrophoresis an...

2013
Yi-Chen Wang Amrita Srivathsan Chen-Chieh Feng Agus Salim Myron Shekelle

Previous studies of meta-analyses found significantly positive correlations between primate species richness and rainfall for Africa, Madagascar and the Neotropics, with the exception of Asia, leaving the open question whether that anomaly is the result of sampling bias, biogeography, or some other factor. This study re-examines the question using modelled data, with primate species richness da...

Journal: :Remote Sensing 2012
Jeffrey A. Wolf Geoffrey A. Fricker Victoria Meyer Stephen P. Hubbell Thomas W. Gillespie Sassan Saatchi

Most plant species are non-randomly distributed across environmental gradients in light, water, and nutrients. In tropical forests, these gradients result from biophysical processes related to the structure of the canopy and terrain, but how does species richness in tropical forests vary over such gradients, and can remote sensing capture this variation? Using airborne lidar, we tested the exte...

Journal: :The American naturalist 2014
Kevin Gross Bradley J Cardinale Jeremy W Fox Andrew Gonzalez Michel Loreau H Wayne Polley Peter B Reich Jasper van Ruijven

The relationship between biological diversity and ecological stability has fascinated ecologists for decades. Determining the generality of this relationship, and discovering the mechanisms that underlie it, are vitally important for ecosystem management. Here, we investigate how species richness affects the temporal stability of biomass production by reanalyzing 27 recent biodiversity experime...

Journal: :Bulletin of entomological research 2004
P A V Borges V K Brown

The arthropod species richness of pastures in three Azorean islands was used to examine the relationship between local and regional species richness over two years. Two groups of arthropods, spiders and sucking insects, representing two functionally different but common groups of pasture invertebrates were investigated. The local-regional species richness relationship was assessed over relative...

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