Community (re)organization in an experimentally fragmented forest landscape: insights from occupancy–scale patterns of common plant species

Abstract

AbstractQuestionHow does experimental habitat fragmentation of a temperate Australian eucalypt forest affect local population patterns of common plant species 22 yr after landscape transformation to a pine plantation?LocationWog Wog Habitat Fragmentation Experiment, southeast Australia.MethodsWe use occupancy–scale relationships to examine the patterns of community organization of common understorey plant species in fragmented forests (small: 0.25 ha; large: 3.062 ha) relative to an intact native forest.ResultsOccupancy–scale patterns for intact forest and large‐sized remnants were isotropic; slope (z) values ranged across all values, from aggregated to scattered. In the smallest remnants, however, mean and median z values, as well as their interquartile range, were significantly lower than expected. The convergence in occupancy–scale relationships in small remnants hints that many of the commonest plant species have become even more common (i.e. aggregated).ConclusionsThe ecological assembly processes that influence common species in small‐sized remnants differ from those in larger remnants and intact forest. Fragmentation effects on assembly processes are greater at smaller patch sizes because these habitats are likely altered by changed environmental filters more so than large patches. Such shifts may have implications for habitat structure, ecosystem function and food web interactions in small remnant forests.