Affiliation:
1. Faculty of Science University of South Bohemia in České Budějovice České Budějovice Czech Republic
2. Ecology and Biodiversity Group Utrecht University Utrecht The Netherlands
3. Plant Ecology Group, Institute of Evolution and Ecology University of Tübingen Tübingen Germany
4. Institute of Entomology Biology Centre of the Czech Academy of Sciences České Budějovice Czech Republic
5. Department of Forest Ecology, Faculty of AgriSciences Mendel University in Brno Brno Czech Republic
6. Faculty of Science and Technology, Institute of Ecology and Earth Sciences University of Tartu Tartu Estonia
Abstract
AbstractQuestionsCover and biomass serve as common measures of species abundance in plant ecology. However, the underlying relationship between these two measures and its implications remain poorly understood. This makes results based on cover and biomass difficult to compare.LocationsWet meadow, southeast of České Budějovice, Czech Republic (48°57′ N, 14°36′ E).MethodWe developed theoretical expectations for systematic differences in characterizing vegetation using cover and biomass for species and community characteristics, including species diversity, temporal dynamics, and responses to experimental manipulations. We then tested these expectations using cover and biomass data from an experimental study of fertilization and dominant removal spanning 14 years (2001–2014).ResultsConsistent with our expectations, on average, species biomass corresponded to the power of species cover, with a power coefficient slightly below 3/2. Community diversity indices calculated using cover and biomass were tightly correlated but were higher for cover. Temporal variabilities based on cover and biomass for individual species were also correlated, but higher for biomass than cover. Though strongly correlated, cover data show much stronger asynchrony, suggesting higher importance of compensatory dynamics. However, using the sum of individual species' cover values as a measure of total community abundance or productivity is problematic. Such a measure is nearly independent of total biomass and leads to contradictory results when used to characterize temporal variability. Species‐ and community‐level responses to treatments were congruent between the measures.ConclusionsOur study provides theoretical background for a convex relationship between plant cover and biomass. The data analysis confirms the relationship and its consequences for describing species‐ and community‐level properties. Most characteristics are well correlated between cover and biomass, but with one metric systematically shifted higher in many cases. Total abundance is the most sensitive measure and is well characterized by sum of biomass, but not by sum of cover. Understanding these systematic differences allows meaningful comparison of studies based on biomass and cover.