题目：Evolutionary modelling: from trees to bumble bees

　　主讲：Magnus Lindh

　　时间：2018-06-05

　　地点：理学院104

　　主办：理学院

　　主讲简介：Magnus Lindh，瑞典斯德哥尔摩大学博士，瑞典隆德大学博士后，长期从事林业资源的建模和分析，共发表高水平论文20余篇。　

　　主讲内容：Our understanding of evolution has advanced significantly since the theory of natural selection was first formulated by Wallace and Darwin in 1858. Although we cannot predict major events such as adaptive radiation and mass extinction, we can predict for example the evolutionary response to environmental change, and the conditions for evolutionary branching. New mathematical tools were developed in the 1990s, introducing simple graphical representations to understand the complex process of evolution. Adaptive dynamics is based on the idea of separation between ecological and evolutionary timescales, and the separation of common residents and rare mutants. In this talk I will go through the basic theory, and give examples from my own research.

　　题目：Model-based investigation on the effects of spatial evenness, and size selection in thinning of Norwegian spruce stands

　　主讲：Peter Fransson

　　时间：2018-06-05

　　地点：理学院104

　　主办：理学院

　　主讲简介：Peter Fransson，瑞典于默奥大学博士，目前在瑞典于默奥大学综合科学实验室工作，长期从事林业资源利用与开发的建模，共发表高水平论文10余篇。　

　　主讲内容：

　　Size and spatial distribution of trees are important for forest stand growth, but it has rarely been documented to what degree they matter in thinning operations, in terms of wood production and stand economy. Here we investigate how the choice of spatial evenness and tree-size distribution of residual trees will impact 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 are defined by three variables: 1) spatial evenness after thinning, 2) tree size preference for harvesting, and 3) basal area reduction.