Temporal change in species and functional plant traits in the moist grassland on the Sete Cidades National Park, Piauí, Brazil.

Mra Mendes,Mc Silva Júnior,Fsc Takahashi,Aajf Castro,Cbr Munhoz

doi:10.1590/1519-6984.18812

Abstract

The present study investigated the dynamic on a short-time scale in the vegetation in moist grassland of the Sete Cidades National Park, Piauí. Herb-subshrub layer samples was carried out in July 2007, 2009 and 2011. Changes in structural, floristic and functional traits in the community were assessed by species richness, diversity and similarity indices between those periods, as well as by hierarchical classification and ordination. Cluster and Principal Component Analyses identified functional groups according to 23 species trait state. To distinguish the contribution of space and time configuration in the community structure, we used the variance partition technique. The functional groups of chamaephytes and therophytes II were associated with wetter sites, while the groups of non-tussock hemicriptophytes I, tussock hemicriptophytes (FG4), and geophytes (FG5) were associated to the drier ones. We found a non-accelerated dynamics, at least on a short-time scale, represented by some descriptors in the community, such as the close similarity between the inventories and ordering of sampling transects in moist grassland. Therefore, besides considering the partition of the temporal niche as a mechanism for the co-existence of species, the heterogeneity of space dictated by environmental filters seems to determine the stability of the this grassland communities over time.

Highlights

The current status of plant communities is the result of a dynamic and complex system, with more subtle changes on large time-scales, as a result, for example; of changes to glacial and interglacial periods (Gurevitch et al, 2009)
We aim to generate information which advances the understanding of dynamic processes in grassland vegetation, assuming that the communities of moist grassland savanna are dynamic over short time
A total of 28 families, 56 genera, and 92 species were recorded, of which 58 species were common in all three samples (Table 1)

Summary

Introduction

The current status of plant communities is the result of a dynamic and complex system, with more subtle changes on large time-scales (ecological and evolutionary), as a result, for example; of changes to glacial and interglacial periods (Gurevitch et al, 2009). One approach is to look at changes in the structure and composition of vegetation with the application of a given sampling method at different moments in time in the same community (Bakker et al, 1996). Such studies can reveal trends in community development, changes in environmental and energy flow in the ecosystem (Šamonil and Vrška, 2008), and generate answers about the stability of plant communities, and design future scenarios that may assist in maintaining biodiversity (Rees et al, 2001). This high mobility can be related to the presence of disturbances in the area whether anthropogenic or natural, such as a recurrent drought and to how the species grow (Klimeš, 1999)

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