Changes in taxonomic and functional diversity of plants in a chronosequence of Eucalyptus grandis plantations

Abstract

Tree plantations have become one of the fastest-growing land uses and their impact on biodiversity was evaluated mainly at the taxonomic level. The aim of this study was to analyze environmental changes after the Eucalyptus plantation in an area originally covered by natural grasslands, taking into account the alpha and beta (taxonomic and functional) diversity of plant communities. We selected nine plantation ages, along a 12 years chronosequence, with three replicates per age and three protected grasslands as the original situation. At each replicate, we established three plots to measure plant species cover, diversity and environmental variables. Results showed that species richness, and all diversity indices, significantly declined with increasing plantation age. Canopy cover, soil pH, and leaf litter were the environmental drivers that drove the decrease in taxonomic and functional diversity of plants through the forest chronosequence. Based on the path analyses results, canopy cover had an indirect effect on plant functional diversity, mediated by leaf litter depth, soil pH, and plant species richness. The high dispersal potential, annual, barochorous, and zoochorous plant species were the functional traits more affected by the eucalypt plantations. We recommend two management practices: reducing forest densities to allow higher light input to the understory and, due to the fact that leaf litter was negatively associated with all diversity facets, we recommend reducing their accumulation or generate heterogeneity in its distribution to enhance biodiversity.

Are metapopulation species drivers of metacommunity structure in sandstone outcrop communities?

“…Furthermore, the relative efficiency of plants using different metabolic photosynthetic pathways to create complex sugars is highly dependent on atmospheric composition as well as climatic drivers (Ward et al, 1999; Mayeux et al, 2021). While including only a subset of present taxa only allows for interpretations based on just those specific taxa, other studies have removed non‐dominant taxa and often singletons from functional analyses, observing little effect on statistical bias and while retaining the ability to detect differences in functional diversity and composition between individual sites (Swenson et al, 2012; Chun & Lee, 2017; Pairo et al, 2021). The resulting phylogeny and dendrograms were used to calculate Faith's phylogenetic diversity (the phylogenetic diversity of a species set as equal to the sum of all branch lengths in the phylogeny that span the members of the set; PD), and distance‐based functional diversity based on Gower's dissimilarity (FD).…”

Age of Eucalyptus plantations differentially affects assemblages of surface‐active arthropods

“…We hypothesised that arthropod composition will differ among eucalypt ages, because different ages differ in structure (Wagner et al, 2006). Furthermore, because of the reduced leaf litter in younger eucalypts (Pairo et al, 2021), we expected lower species richness than in the older age groups.…”

“…For example, plantations with recently planted seedlings support other plant species (Wagner et al, 2006). However, as trees grow and canopies close, species richness of plants that are intolerant of shade decreases, while the leaf litter depth increases (Pairo et al, 2021).…”

“…Vegetation structure, which determines environmental conditions in eucalypts, is expected to vary depending on the growth phase (Pairo et al, 2021). For example, plantations with recently planted seedlings support other plant species (Wagner et al, 2006).…”

Geographical trends of soil‐associated biodiversity changes due to tree plantations in South America: Biome and climate constraints revealed through meta‐analysis

“…AET/climate seasonality, regional agricultural cover, plantation age); (iii) Identify potential geographical trends of change in species richness of above‐ and below‐ground communities to tree plantations in South America. Commercial plantations are monoculture stands that imply a great disturbance for their initiation, with simplified strata when matured (Pairo et al, 2021; Santoandré et al, 2019). Thus, we predict an overall negative effect of commercial plantations on species richness.…”