title: Alpha and beta diversity of plants and animals along a tropical land-use gradient.
abstract: Assessing the overall biological diversity of tropical rain forests is a seemingly insurmountable task for ecologists. Therefore, researchers frequently sample selected taxa that they believe reflect general biodiversity patterns. Usually, these studies focus on the congruence of alpha diversity (the number of species found per sampling unit) between taxa rather than on beta diversity (turnover of species assemblages between sampling units). Such approaches ignore the potential role of habitat heterogeneity that, depending on the taxonomic group considered, can greatly enhance beta diversity at local and landscape scales. We compared alpha and beta diversity of four plant groups (trees, lianas, terrestrial herbs, epiphytic liverworts) and eight animal groups (birds, butterflies, lower canopy ants, lower canopy beetles, dung beetles, bees, wasps, and the parasitoids of the latter two) at 15 sites in Sulawesi, Indonesia, that represented natural rain forest and three types of cacao agroforests differing in management intensity. In total, we recorded 863 species. Patterns of species richness per study site varied strongly between taxonomic groups. Only 13-17% of the variance in species richness of one taxonomic group could be predicted from the species richness of another, and on average 12-18% of the variance of beta diversity of a given group was predicted by that in other groups, although some taxon pairs had higher values (up to 76% for wasps and their parasitoids). The degree of congruence of patterns of alpha diversity was not influenced by sampling completeness, whereas the indicator value for beta diversity improved when using a similarity index that accounts for incomplete sampling. The indication potential of alpha diversity for beta diversity and vice versa was limited within taxa (7-20%) and virtually nil between them (0-4%). We conclude that different taxa can have largely independent patterns of alpha diversity and that patterns of beta diversity can be more congruent. Thus, conservation plans on a landscape scale need to put more emphasis on the high heterogeneity of agroforests and the overarching role of beta diversity shaping overall diversity patterns.
authors.affiliation: Albrecht-von-Haller-Institute of Plant Sciences, University of Göttingen, 37073 Göttingen, Germany. michael.kessler@systbot.uzh.ch
authors.forename: Michael
authors.initials: M
authors.lastname: Kessler
authors.forename: Stefan
authors.initials: S
authors.lastname: Abrahamczyk
authors.forename: Merijn
authors.initials: M
authors.lastname: Bos
authors.forename: Damayanti
authors.initials: D
authors.lastname: Buchori
authors.forename: Dadang Dwi
authors.initials: DD
authors.lastname: Putra
authors.forename: S Robbert
authors.initials: SR
authors.lastname: Gradstein
authors.forename: Patrick
authors.initials: P
authors.lastname: Höhn
authors.forename: Jürgen
authors.initials: J
authors.lastname: Kluge
authors.forename: Friederike
authors.initials: F
authors.lastname: Orend
authors.forename: Ramadhaniel
authors.initials: R
authors.lastname: Pitopang
authors.forename: Shahabuddin
authors.initials: S
authors.lastname: Saleh
authors.forename: Christian H
authors.initials: CH
authors.lastname: Schulze
authors.forename: Simone G
authors.initials: SG
authors.lastname: Sporn
authors.forename: Ingolf
authors.initials: I
authors.lastname: Steffan-Dewenter
authors.forename: Sri S
authors.initials: SS
authors.lastname: Tjitrosoedirdjo
authors.forename: Teja
authors.initials: T
authors.lastname: Tscharntke
mesh_terms: D000383:Agriculture; D000818:Animals; D044822:Biodiversity; D001717:Birds; D003247:Conservation of Natural Resources; D007214:Indonesia; D007313:Insecta; D010944:Plants; D014197:Trees; D014329:Tropical Climate