Cascading effects of changes in land use on the invasion of the walnut Juglans regia in forest ecosystems

1. Plant invasions are affected by many factors that must be favourable in order for invasions to occur. Factors can be grouped into three major categories: propagule pressure, biotic factors and abiotic characteristics; all may be moderated by human activity. However, studies examining all factors simultaneously are rare, and most are limited to a single factor. This hampers our understanding of the mechanisms driving invasions. 2. In recent decades, an alien walnut (Juglans regia) has become invasive in Central Europe due to an increase in the populations of native dispersers, rooks (Corvus frugilegus), and political changes that have resulted in the abandonment of farmland. Here, we test whether increased propagule pressure resulting from the presence of seed-bearing walnuts in abandoned fields interacts with native forest-seed dispersing animals (biotic factors), landscape structure and management, and passive secondary dispersal by gravity (abiotic factors) to facilitate the furthe...1. 植物入侵受诸多利于入侵发生的因素调控。这些因素可划分为三大类别：繁殖体压力（propagule pressure）、生物因子与非生物特征；所有因素均可能受到人类活动的调节。然而，同时综合考量所有因素的相关研究极为匮乏，多数研究仅局限于单一因素，这阻碍了我们对驱动植物入侵的内在机制的深入理解。2. 近数十年来，由于本地扩散者——秃鼻乌鸦（Corvus frugilegus）种群数量的增长，以及引发农田撂荒的政策变革，外来植物普通胡桃（Juglans regia）已在中欧地区成功入侵。本研究旨在验证：农田撂荒区域内结籽核桃的存在所带来的繁殖体压力提升，是否会与本地森林种子扩散动物（生物因子）、景观结构与管理模式，以及重力介导的被动二次扩散（非生物因子）相互作用，进而促进其最远……