a 2008

Species richness in European steppes : role of productivity, soil depth and pH

MERUNKOVÁ, Kristina, Zdenka OTÝPKOVÁ and Milan CHYTRÝ

Basic information

Original name

Species richness in European steppes : role of productivity, soil depth and pH

Name in Czech

Druhová bohatost evropských stepí : vliv produktivity, hloubky půdy a pH

Authors

MERUNKOVÁ, Kristina, Zdenka OTÝPKOVÁ and Milan CHYTRÝ

Edition

The International Association For Vegetation Science: 51st Annual Symposium, Stellenbosch, South Africa, 2008

Other information

Language

English

Type of outcome

Konferenční abstrakt

Field of Study

10600 1.6 Biological sciences

Country of publisher

South Africa

Confidentiality degree

není předmětem státního či obchodního tajemství

Organization unit

Faculty of Science

ISBN

978-0-9584766-9-0

Keywords in English

grasslands; diversity; species pool; biomass
Změněno: 14/1/2009 13:55, Mgr. Kristina Merunková, Ph.D.

Abstract

V originále

Productivity and soil pH are commonly recognised as influential determinants of grassland vegetation diversity. So far, little is known about factors influencing local richness in steppe grasslands of subcontinental and continental areas of Europe. We sampled steppe vegetation in two regions: the Southern Urals, situated within the Euro-Siberian steppe zone, and the Czech Republic, situated at the margin of the forest-steppe zone. By simultaneously studying these contrasting regions we aimed to recognise major patterns in species richness and see how they relate to productivity, soil depth and pH. Steppe vegetation types varying in soil depth, pH and productivity were represented in both data sets. Vascular plant species richness was determined for 100 m2 plots. Aboveground non-woody biomass was collected from a 0.25 m2 subplot located in each plot and used as an estimate of site productivity. Soil depth was measured in three places of each plot and averaged. Similarly, soil pH was measured from a mixed soil sample taken from three places in each plot. Species richness increases with productivity in both the Czech and the Uralian steppes. Due to their general dryness, productivity of most steppe vegetation types is relatively low. In addition, strong moisture fluctuations in steppe soils make it difficult for competitive species to become dominant in the stands. Competitive exclusion is probably not a major force, therefore we do not observe the typical unimodal or even decreasing response of species richness to productivity, commonly reported from grasslands with higher and more balanced water supply. Productivity is strongly related to soil depth. Interestingly, in the Uralian steppes soil depth is a markedly better predictor of species richness than their productivity, while in the Czech steppes the effect of both predictors is comparable. This implies that soil depth not only affects species richness through its effect on productivity, but also in its own way. Species richness increases along the pH gradient in both regions. However, in the Uralian steppes, there is a peak at pH 6.8 followed by a decrease towards the highest-pH soils. In the Czech steppes, such indication of unimodality also appears once soil depth is included in the model. Low species richness at low-pH soils corresponds to a relatively small species pool of acidic substrates. The decrease in number of species at high pH may by due to severe site dryness, often connected with these high-pH soils. To conclude, in European steppes most species occur at deep, productive soils with pH of 6-7.5. Soil depth and pH can together explain about half of the variation in species richness both in the Uralian and the Czech steppes.

In Czech

Produktivita a půdní pH jsou faktory se zásadním vlivem na diverzitu vegetace. Doposud není mnoho známo o tom, co určuje druhovou bohatost stepí subkontinentálních a kontinentálních oblastí Evropy. Snímkovali jsme stepní vegetaci dvou oblastí - jižního Uralu a České republiky. Druhová bohatost stoupá s produktivitou jak v českých, tak v uralských stepích. Ve srovnání s produktivitou je výrazně lepším prediktorem druhové bohatosti uralských stepí hloubka půdy. U českých stepí mají oba tyto prediktory srovnatelný vliv. Druhová bohatost obou území roste dále s půdním pH, s výjimkou nejvíce zásaditých půd (pH nad 6,8) na Urale, u kterých je diverzita nižší. Hloubka půdy a pH dohromady vysvětlují asi polovinu variability v počtu druhů pozorované u českých i uralských stepí.

Links

IAA6163303, research and development project
Name: Diverzita vegetace podél gradientu kontinentality na jižní Sibiři: klíč k pochopení raně postglaciální historie střední Evropy
Investor: Academy of Sciences of the Czech Republic, Vegetation diversity along a continentality gradient in southern Siberia: a key to understanding Early Postglacial history of Central Europe
MSM0021622416, plan (intention)
Name: Diverzita biotických společenstev a populací: kauzální analýza variability v prostoru a čase
Investor: Ministry of Education, Youth and Sports of the CR, Diversity of Biotic Communities and Populations: Causal Analysis of variation in space and time
SP/2D3/54/07, research and development project
Name: Syntéza poznatků o stavu biodiverzity travních porostů v CHKO Bílé Karpaty s cílem vytvoření metodiky pro zachování biodiverzity tohoto ekosystému
Investor: Ministry of the Environment of the CR, Synthesis of data on the state of grassland biodiversity in the White Carpathians Protected Landscape Area aimed at biodiversity preservation of this ecosystem