文献类型：期刊文献

英文题名：A new nearest-neighbour index for monitoring spatial size diversity: The hyperbolic tangent index

作者：Pommerening, Arne[1] Szmyt, Janusz[2] Zhang, Gongqiao[3]

第一作者：Pommerening, Arne

通信作者：Zhang, GQ[1]

机构：[1]Swedish Univ Agr Sci SLU, Fac Forest Sci, Dept Forest Ecol & Management, Skogsmarksgrand 17, SE-90183 Umea, Sweden;[2]Poznan Univ Life Sci, Fac Forestry, Dept Silviculture, Ul Wojska Polskiego 71a, PL-60625 Poznan, Poland;[3]Chinese Acad Forestry, Res Inst Forestry, Key Lab Tree Breeding & Cultivat, Natl Forestry & Grassland Adm, Box 1958, Beijing 100091, Peoples R China

年份：2020

卷号：435

外文期刊名：ECOLOGICAL MODELLING

收录：;EI(收录号：20203909223703);Scopus(收录号：2-s2.0-85091240612);WOS:【SCI-EXPANDED(收录号:WOS:000575085700011)】；

基金：The authors thank Oscar Garcia (Dasometrics, formerly University of Northern British Columbia) for an interesting and inspiring discussion about the hyperbolic tangent index. He contributed valuable conceptual ideas. Markus Neumann (Austrian Federal Research and Training Centre for Forests, Natural Hazards and Landscape, Vienna, Austria) kindly provided the Karlstift P. abies time series data to this study for which the authors are very grateful. G.Z.'s research visit to Umea was funded by the Fundamental Research Funds for the Central Non-profit Research Institution of the Chinese Academy of Forestry (project number CAFYBB2019GC001-2).

语种：英文

外文关键词：Spatial size diversity; Indicator construction principles; Size diversity maintenance; Climate change; Individual-based modelling; Mixed-species woodlands; Trigonometry

摘要：Understanding natural mechanisms of maintaining diversity is a crucial pre-requisite for successfully mitigating adverse effects of climate change such as the loss of diversity. To make such an understanding possible, both experiments and an effective, continued monitoring of diversity are required. Recently spatial measures of plant diversity have greatly contributed to the quality of diversity monitoring. In this article, we first reviewed existing principles of nearest-neighbour index construction and on this basis introduced a new spatially explicit size diversity index that is based on trigonometry, i.e. the hyberbolic tangent index. We discussed the index' mathematical reasoning by explaining its relationship to individual-based modelling and to other size diversity construction principles. Then we demonstrated the usefulness of the hyperbolic tangent index in indicating important interspecific relationships in mixed-species forest ecosystems. As part of studying the behaviour of the new size diversity construction principle we additionally found that there is a high correlation between the hyberbolic tangent index and absolute growth rates, i.e. the index is suitable both as a diversity and a competition index. Finally a detailed correlation analysis in a Norway spruce forest ecosystem with tree densities between 590 and 3800 trees per hectare made us understand that in most cases 7-10 neighbours are sufficient to consider when calculating the hyperbolic tangent index for explaining absolute growth rates. When using the index as an indicator of plant diversity only, smaller numbers of nearest neighbours may suffice. The index is straightforward to apply even, if the monitoring system used involves small circular sample plots.