Department of Veterinary Medicine, University of Sassari, Sassari, Italy.
Department of Forest & Wildlife Ecology, University of Wisconsin-Madison, Russell Labs, Madison, Wisconsin, United States of America.
PLoS One. 2019 Nov 6;14(11):e0224788. doi: 10.1371/journal.pone.0224788. eCollection 2019.
Forest development is a complex phenomenon which, for the number of actors involved and the response time expressed by forests, is difficult to understand and explore. Forests in Italy, as in several areas of Europe, are experiencing intensive management and recently, an increasing impact by ungulates. The effects on forest development of these two disturbances combined are difficult to predict, and consequently to be properly managed. We used a forest landscape change model, LANDIS-II, to simulate forest development as driven by forestry practices and roe deer impact for 200 years in a mountain forest of the Italian Apennines. We found that each disturbance alters forest tree species richness, forest type abundance and distribution, and forest structure. When considered combined, the two disturbances show additive behavior, enhancing or moderating each other's effects. Forest management has a negative effect on tree species richness. We expected roe deer to have a negative effect on harvest yields, but this result was significant only for two of seven harvesting treatments. On the other hand, roe deer presence had a positive effect on tree species richness. All the simulation scenarios returned some extent of forest loss. The amount of the forest loss is lowest in the scenario without disturbances, and greatest when both disturbances are considered. However, the two disturbances combined, with the magnitude modelled in our simulations, have relatively low effects on the forest dynamics we analyzed in our study area. LANDIS-II was an effective approach for simulating combined management and ungulate driven trends of forest development, and to help understand the dynamics that lay behind it.
森林发展是一种复杂的现象，由于涉及的行为者众多，森林的反应时间较长，因此很难理解和探索。意大利的森林与欧洲的几个地区一样，正在经历集约化管理，最近还受到了更多有蹄类动物的影响。这两种干扰共同作用对森林发展的影响很难预测，因此也很难进行妥善管理。我们使用了一个森林景观变化模型 LANDIS-II，来模拟意大利亚平宁山脉的一个山地森林在 200 年内受到林业经营和狍鹿影响下的森林发展情况。我们发现，每种干扰都会改变森林树种的丰富度、森林类型的丰度和分布以及森林结构。当两种干扰结合考虑时，它们表现出相加的行为，相互增强或缓和彼此的影响。森林管理对树种丰富度有负面影响。我们预计狍鹿会对采伐产量产生负面影响，但只有在七种采伐处理中的两种情况下才会出现这种结果。另一方面，狍鹿的存在对树种丰富度有积极影响。所有模拟情景都导致了一定程度的森林损失。在没有干扰的情景下，森林损失的程度最低，而在同时考虑两种干扰的情况下，森林损失的程度最高。然而，在我们模拟的规模下，两种干扰的共同作用对我们研究区域的森林动态的影响相对较小。LANDIS-II 是一种有效的方法，可以模拟综合管理和有蹄类动物驱动的森林发展趋势，并帮助理解其背后的动态。
