Model-based investigation on the effects of spatial evenness, and size selection in thinning of Picea abies stands
 作者： Peter Fransson,  Urban Nilsson,  Ola Lindroos,  Oskar Franklin,  Åke Brännström 作者单位： 1Department of Mathematics and Mathematical Statistics , Umeå University , Umeå , Sweden2Southern Swedish Forest Research Centre , Swedish University of Agricultural Sciences , Alnarp , Sweden3Department of Forest Biomaterials and Technology , Swedish University of Agricultural Sciences , Umeå , Sweden4Ecosystems Services and Management Program , International Institute for Applied Systems Analysis , Laxenburg , Austria5Evolution and Ecology Program , International Institute for Applied Systems Analysis , Laxenburg , Austria 刊名： Scandinavian Journal of Forest Research, 2019, Vol.34 (3), pp.189-199 来源数据库： Taylor & Francis Journal DOI： 10.1080/02827581.2019.1577914 关键词： Thinning;  Individual-based model;  Spatial distribution;  Forest management;  Simulation; 原始语种摘要： ABSTRACT(#br)Size and spatial distribution of trees are important for forest stand growth, but the extent to which it matters in thinning operations, in terms of wood production and stand economy, has rarely been documented. Here we investigate how the choice of spatial evenness and tree-size distribution of residual trees impacts wood production and stand economy. A spatially explicit individual-based growth model was used, in conjunction with empirical cost functions for harvesting and forwarding, to calculate net production and net present value for different thinning operations in Norway spruce stands in Northern Sweden. The in silico thinning operations were defined by three variables: (1) spatial evenness after thinning, (2) tree size preference for harvesting, and (3) basal area... reduction. We found that thinning that increases spatial evenness increases net production and net present value by around 2.0%, compared to the worst case. When changing the spatial evenness in conjunction with size preference we could observe an improvement of the net production and net present value up to 8.0%. The magnitude of impact differed greatly between the stands (from 1.7% to 8.0%) and was highest in the stand with the lowest stem density.

• spatial　空间的
• thinning　狭缩
• selection　选择
• evenness　均匀度
• stands
• economy　经济
• preference　优选
• production　生产
• empirical　经验的
• based　基于