Abstract

Background A number of hypotheses and theories, such as the Janzen-Connell hypothesis, have been proposed to explain the natural maintenance of biodiversity in tropical and temperate forest ecosystems. However, to date the details of the processes behind this natural maintenance are still unclear. Recently two new nearest-neighbour characteristics were proposed and in this paper we demonstrate how they can contribute to a better understanding of the ontogenesis of global forest structure from localised neighbourhoods. Methods We applied the new species and size segregation functions together with appropriate test procedures to four example woodland data sets from China at Daqingshan, Jiaohe, Jiulongshan and Xiaolongshan forest regions. In addition we quantified the morphology of the new characteristics and modelled a neighbourhood allometric coefficient linking the two functions. Results The results revealed quite different species segregation patterns with both conspecific and heterospecific attraction. We found these to be generally matched by equivalent size segregation patterns of attraction of similar and different sizes. It was straightforward to model the size segregation function from the knowledge of the species segregation function by estimating a neighbourhood allometric coefficient. Conclusions The new characteristics have helped to quantify the extent and rate of decline of neighbourhood interactions in terms of spatial species and size diversity. Through the allometric neighbourhood coefficient the analysis highlighted once more how closely related species and size segregation are, thus supporting the mingling-size hypothesis. Using both a traditional and a restricted random-labelling test has provided a valuable tool for understanding the exact nature of species-mingling and size-inequality relationships.

Keywords

Species segregation function; Size segregation function; Mingling-size hypothesis; Neighbourhood allometric coefficient; random labelling

Published in

Forest Ecosystems
2020, Volume: 7, number: 1, article number: 22
Publisher: SPRINGER

SLU Authors

• Pommerening, Arne

  • Department of Forest Ecology and Management, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Forest Science


Publication identifier

DOI: https://doi.org/10.1186/s40663-020-00224-5

Permanent link to this page (URI)

https://res.slu.se/id/publ/105348