نتایج جستجو برای: species richness and abundance of soil invertebrates
تعداد نتایج: 24092366 فیلتر نتایج به سال:
BACKGROUND "The enigma of soil animal species diversity" was the title of a popular article by J. M. Anderson published in 1975. In that paper, Anderson provided insights on the great richness of species found in soils, but emphasized that the mechanisms contributing to the high species richness belowground were largely unknown. Yet, exploration of the mechanisms driving species richness has fo...
BACKGROUND Although community structure and species richness are known to respond to nitrogen fertilization dramatically, little is known about the mechanisms underlying specific species replacement and richness loss. In an experiment in semiarid temperate steppe of China, manipulative N addition with five treatments was conducted to evaluate the effect of N addition on the community structure ...
This study investigates the role of man-made disturbance on on nitrogen and phosphorus nutrient storage by herbaceous species in Gall Oak stands of Lorestan province. In order to do this study, two sites with the same physiographic and ecological conditions and different land uses were selected. Multiscale sampling plots were used randomly in each site to collect data on forest floor vegetation...
Abstract Hermit crabs community in the intertidal zones of Larak Island were investigated through a seasonal sampling at five stations using random quadrate sampling method. Overall, seven species were identified and Clibanarius signatus was the dominant species, which showed high dominance over other species. Using Bray-Curtis cluster analysis for comparing seasonal abundance showed that exce...
the effects of land use, crop type and crop management on soil fauna were investigated with survey of four habitats in jajarm. the habitats included rangelands, alfalfa (medicago sativa l.) fields and low-input and high-input of wheat (triticum aestivum l.) fields, each with four sample units. in each sample unit, the macrofauna collected with pitfall traps, sorted and counted in terms of famil...
this work is presented in five parts. in the first part preparation of the starting complex [pt(c^n)cl(dmso)], 1, in which c^n = n(1),c(2?)-chelated, deprotonated 2-phenylpyridine, and dmso = dimethylsulfoxide, and its reaction with 1 equiv of the biphosphine ligands bis(diphenylphosphino)amine, dppa, or bis(diphenylphosphino)methane, dppm, to give the complex [pt(c^n)cl(dppa)], 2, or [pt(c^n)c...
Pollinating insect populations, essential for maintaining wild plant diversity and agricultural productivity, rely on (semi)natural habitats. An increasing human population is encroaching upon and deteriorating pollinator habitats. Thus the population persistence of pollinating insects and their associated ecosystem services may depend upon on man-made novel habitats; however, their importance ...
We used 116 years of floral and faunal records from Mandarte Island, British Columbia, Canada, to estimate the indirect effects of humans on plant communities via their effects on the population size of a surface-nesting, colonial seabird, the Glaucous-winged gull (Larus glaucescens). Comparing current to historical records revealed 18 extirpations of native plant species (32% of species histor...
The relationship between plant diversity and productivity in grasslands could depend, partly, on how diversity affects vertical distributions of root biomass in soil; yet, no prior study has evaluated the links among diversity, root depth distributions, and productivity in a long-term experiment. We used data from a 12-year experiment to ask how plant species richness and composition influenced...
Pteridium aquilinum is known as an invasive species in different ecosystems of the world. The spread of this species is increasing in the north of Iran particularly outside of forest ecosystems. In this study, the amount and composition of soil seed banks in the dense pathes of Pteridium were investigated in summer rangelands of Bandpay in the south of Babol city in Mazandaran province, Iran...
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