Data from: Diverse guilds provide complementary dispersal services in a woodland expansion process after land abandonment

1. Land abandonment due to increasing depopulation of rural areas is an ongoing trend in developed countries worldwide. Abandoned lands represent an opportunity for ecosystem recovery, an urgent need for biodiversity conservation. Seed dispersal services provided by animals are a key feature for this process. Different dispersers may differentially contribute to plant recruitment under different ecological conditions, leading to complementary dispersal services. 2. We studied the dispersal services, quantified as the contribution to plant recruitment, provided by the main dispersal guilds of Spanish juniper Juniperus thurifera L.: small-to-medium sized strongly frugivorous birds (thrushes) and medium-to-large sized carnivorous mammals (red fox and stone marten). To do this, we studied seed fate from seed dispersal to seedling survival during two years and estimated seed dispersal effectiveness (seedlings recruited per m2) in two ecological contexts derived from ecosystem recovery after a historical period of degradation: remnant woodlands and old fields. 3. Results showed a clear shift in the contribution to plant recruitment between these guilds, resulting in complementary and non-redundant dispersal services. Thrushes were the main contributors to plant recruitment in woodlands (73%), leading to population growth but with a reduced impact on the colonization of old fields where carnivores contributed to 80% of recruitment (42% red fox, 38% stone marten). The dispersal complementarity observed for thrushes and carnivores is a consequence of their functional diversity, mainly driven by their differences in feeding and movement behaviour. 4. Synthesis and applications. The combination of short distance, strongly frugivorous dispersers (e.g. passerine birds) together with big generalist frugivores with long distance movements (e.g. carnivorous mammals) maintained (i) effective seed dispersal services in remnant woodlands and (ii) the connectivity between patches promoting old fields colonization and woodland expansion. Thus, it is in heterogeneous landscape mosaics ecosystems (e.g. agro-environments) where functionally diverse disperser communities play a key role in ecosystem recovery. By performing effective dispersal services across an array of habitat types, functionally diverse disperser communities assist natural restoration of human-impacted ecosystems all over the world. Thus, dispersal communities provide an important ecosystem service that may replace costly human-mediated restoration projects.

1. 全球发达国家中，因农村人口持续减少引发的土地撂荒已是长期蔓延的趋势。撂荒地为生态系统恢复提供了重要契机，而这也是生物多样性保护的迫切需求。动物介导的种子扩散服务是该生态恢复过程的关键环节。不同的扩散者类群在不同生态条件下对植物定居的贡献存在差异，由此形成互补性的扩散服务。
2. 本研究针对西班牙刺柏（Juniperus thurifera L.）的主要扩散功能群所提供的扩散服务展开探究，以其对植物定居的贡献作为量化指标。该刺柏的两大扩散功能群分别为：中小型强食果性鸟类（鸫类），以及中大型食肉哺乳动物（赤狐与石貂）。研究周期为两年，内容涵盖从种子扩散至幼苗存活的完整种子命运过程，并在两种由历史退化后生态恢复形成的生态场景中估算了种子扩散有效性（单位面积定植幼苗数）：残存林地与撂荒地。
3. 研究结果显示，两大功能群对植物定居的贡献存在显著分化，最终形成互补且无冗余的扩散服务。在残存林地中，鸫类是植物定居的主要贡献者（占比73%），推动了种群增长，但对撂荒地的殖民过程影响有限；而在撂荒地的植物定居中，食肉动物贡献了80%的份额（其中赤狐占42%，石貂占38%）。鸫类与食肉动物之间的扩散互补性，源于二者的功能多样性，主要由其取食与运动行为的差异所驱动。
4. 综合与应用。兼具短距离扩散的强食果性扩散者（如雀形目鸟类）与具备长距离运动能力的大型广食果性动物（如食肉哺乳动物）的组合，既（i）维持了残存林地中高效的种子扩散服务，又（ii）促进了斑块间连通性，推动撂荒地的殖民与林地扩张。因此，在异质化的景观镶嵌生态系统（如农业复合生境）中，功能多样的扩散者群落对生态系统恢复发挥着关键作用。这类功能多样的扩散者群落可通过在多种生境类型中提供高效的扩散服务，助力全球范围内受人类活动干扰的生态系统实现自然恢复。由此可见，扩散者群落所提供的重要生态系统服务，可替代成本高昂的人工介导修复工程。