نتایج جستجو برای: species richness

تعداد نتایج: 556166  

Journal: :Neotropical entomology 2010
Soraia Diniz Paulo I Prado Thomas M Lewinsohn

Anthropogenic changes in the landscape result in an environmental mosaic with serious consequences for biodiversity. The aim of the present study was to assess the effects of the anthropogenic changes on Asteraceae richness and abundance, and to evaluate the consequences for the richness of Tephritidae assemblages in five sampling sites, with three sampled habitats in each: cerrado (Brazilian s...

The study was conducted to assess the native and alien plant species in one of the highly disturbed forest (S1) and less disturbed forest (S2) in Mt. Manunggal, Cebu Island, Philippines. Twenty-four quadrats with a size of 20mx20 m were established using a quadrat sampling technique to identify and record all plant species. Diversity indices were utilized to determine species abundance, richnes...

Journal: :The American naturalist 2005
Nick J B Isaac Kate E Jones John L Gittleman Andy Purvis

We present the most extensive examination to date of proposed correlates of species richness. We use rigorous phylogenetic comparative techniques, data for 1,692 mammal species in four clades, and multivariate statistics to test four hypotheses about species richness and compare the evidence for each. Overall, we find strong support for the life-history model of diversification. Species richnes...

2016
Xixi Wang Wenxing Long Brandon S. Schamp Xiaobo Yang Yong Kang Zhixu Xie Menghui Xiong

Vascular epiphytes are important components of biological diversity in tropical forests. We measured the species richness and abundance of vascular epiphytes along four vertical crown zones and five horizontal orientations on 376 trees, as well as the diameter at breast height (DBH) of host trees in tropical cloud forests in Bawangling, Hainan, China. The relationship between vascular epiphyte ...

2007
Michael D. Weiser Brian J. Enquist Brad Boyle Timothy J. Killeen Peter M. Jørgensen Gustavo Fonseca Michael D. Jennings Andrew J. Kerkhoff Abel Monteagudo Percy Núñez Vargas Oliver L. Phillips Nathan G. Swenson Rodolfo Vásquez Martínez

Aim Relationships between range size and species richness are contentious, yet they are key to testing the various hypotheses that attempt to explain latitudinal diversity gradients. Our goal is to utilize the largest data set yet compiled for New World woody plant biogeography to describe and assess these relationships between species richness and range size. Location North and South America. ...

Journal: :Ecology 2008
Brian M Starzomski Raenelle L Parker Diane S Srivastava

What are the local community consequences of changes in regional species richness and composition? To answer this question we followed the assembly of microarthropod communities in defaunated areas of moss, embedded in a larger moss "region." Regions were created by combining moss from spatially distinct sites, resulting in regional species pools that differed in both microarthropod richness an...

Journal: رستنیها 2011
H. Riahi, Z. Shariatmadari

Four paddy fields in Guilan province in the north of Iran seasonally were sampled from April 2008 to January 2009. Twenty-two morphospecies belonging to three families of the heterocystous blue-green algae were identified. Fourteen species and one variety of these taxa are new record for Iran. Among the families Nostocaceae with six genera and 16 species showed the highest species richness.

2014
Grace E P Murphy Tamara N Romanuk

There is high uncertainty surrounding the magnitude of current and future biodiversity loss that is occurring due to human disturbances. Here, we present a global meta-analysis of experimental and observational studies that report 327 measures of change in species richness between disturbed and undisturbed habitats across both terrestrial and aquatic biomes. On average, human-mediated disturban...

Journal: :Conservation biology : the journal of the Society for Conservation Biology 2012
Alexandre Camargo Martensen Milton Cezar Ribeiro Cristina Banks-Leite Paulo Inácio Prado Jean Paul Metzger

Theoretical and empirical studies demonstrate that the total amount of forest and the size and connectivity of fragments have nonlinear effects on species survival. We tested how habitat amount and configuration affect understory bird species richness and abundance. We used mist nets (almost 34,000 net hours) to sample birds in 53 Atlantic Forest fragments in southeastern Brazil. Fragments were...

Journal: :حفاظت گیاهان 0
علیرضا خداشناس علیرضا کوچکی پرویز رضوانی مقدم حسین صادقی نامقی مهدی نصیری محلاتی

spiders are one of the most abundant invertebrates in terrestrial ecosystems that have a good potential to pest control in crops. species richness and abundance of spiders and the effects of different agricultural practices on these predators were studied in winter wheat fields in shirvan, mashhad and gonabad, cities in northeast of iran. in each region, high and low input fields of winter whea...

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