The influence of productivity on the species richness of plants: a critical assessment.

نویسندگان

  • Len N Gillman
  • Shane D Wright
چکیده

Despite much scrutiny the relationship between productivity and species richness remains controversial, and there is little agreement about causal processes. We present the results of a survey of 159 productivity-plant species richness (P-PSR) relationships from 131 published studies. We critically assessed each study with respect to experimental design and for the appropriateness of the surrogates used for productivity. We were able to accept only 60 of the reported relationships as robust tests of the P-PSR relationship and a further 18 as robust tests of the biomass species richness relationship. Previous analyses have found that unimodal P-PSR relationships predominate. In contrast, we found that, in studies that used data of continental to global extent, all P-PSR relationships were positive regardless of grain, that almost all were also positive in data sets of regional extent, and that unimodal relationships were not dominant even in studies of fine grain or small spatial extent. Our results differ substantially from previous meta-analyses because previous studies have included a large number of studies that do not meet basic experimental design criteria for objectively testing P-PSR relationships. These results have important implications for theory that attempts to explain species richness patterns. We critically review four dominant theories in light of our results and develop new falsifiable predictions of relationship from these theories at both small and large spatial scales.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Assessment of Health Conditions of Mountain Rangeland Ecosystem Using Species Diversity and Richness Indices, Case Study: Central Alborz (Iran)

Based on the importance and role of species diversity and richness as ameasurement of the health of an ecosystem; studying of their components can lead toevaluate the health condition of rangeland. This research was carried out in a part ofhighland mountainous rangeland of Mount Alborz Range in Iran. Diversity and richnesswere assessed as an ecosystem health indicator. The study area was locate...

متن کامل

Change of Species Diversity in Vascular Plants Across Ecological Species Groups

Biodiversity plays a crucial role in stability and productivity of natural ecosystem. The main goal of this research was to classify ecological groups in steppe rangeland and investigate their relationships with plant diversity indices. Therefore, fifty different Land Unit Tracts (LUT) were identified in Khod-Neuk basin, Yazd province, Iran, in 2010. Vegetation and soil samples were taken in th...

متن کامل

Vegetation characteristics of four ecological zones of Iran

Environmental (topography, climate) features have an important influence on plant diversity and richness of Iran. Topography is from –28m which is close to Caspian Sea to 5678m which is located on the Alborz Mountain. Two mountains (Alborz and Zagrosss) prevent moist air moving to the centre of Iran. On the basis of environmental factors, four ecological zones with specific plant richness from ...

متن کامل

Effect of shrub type on species diversity and richness of soil seed bank in semiarid regions (case study: Chenarnaz rangelands, Khatam city, Yazd province)

Soil seed bank can facilitate natural regeneration of rangeland ecosystems. This bank is usually influenced by local plant species. This study was conducted to investigate the effect of canopy cover of three shrubs (Amygdalus scoparia, Daphne mezereum and Ebenus stellata) on the diversity and richness of soil seed bank under their canopies in Chenarnaz rangelands, Khatam city, Yazd province. Fi...

متن کامل

The Effect of Altitude and Aspect on Rangeland Plant Diversity (Case Study: Dashte Zahab, Kermanshah, Iran)

Recognizing the herbaceous plant species diversity could use as an importantindicator applied for the rangeland and forests management. Considering the presence ofvegetation and animal husbandry in Zagros region, Iran, being aware of the diversity andrichness of plant species is necessary to management or the destructed vegetationrestoration. In order to study the effect of aspect and elevation...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:
  • Ecology

دوره 87 5  شماره 

صفحات  -

تاریخ انتشار 2006