Long-term data are important to understand the changes in ecological communities over time but are quite rare for insects. We analyzed such changes using historic museum collections. For our study area, an isolated forest reserve in North-East Italy, data from the past 80 yr were available. We used records of 300 moth species to analyze whether extinction risk was linked to their body size or to their degree of ecological specialization. Specialization was scored 1) by classifying larval food affiliations, habitat preferences, and the northern distributional limit and 2) by analyzing functional dispersion (FDis) within species assemblages over time. Our results show that locally extinct species (mean wingspan: 37.0 mm) were larger than persistent (33.2 mm) or previously unrecorded ones (30.7 mm), leading to a smaller mean wingspan of the moth community over time. Some ecological filters appear to have selected against bigger species. By using coarse specialization categories, we did not observe any relationship with local extinction risk. However, FDis, calculated across 12 species traits, significantly decreased over time. We conclude that simple classification systems might fail in reflecting changes in community-wide specialization. Multivariate approaches such as FDis may provide deeper insight, as they reflect a variety of ecological niche dimensions. With the abandonment of extensive land use practices, natural succession seems to have shifted the moth community toward a preponderance of forest-affiliated species, leading to decreased FDis values. Multivariate analyses of species composition also confirmed that the moth community has significantly changed during the last 80 yr.

中文翻译：

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处于较高威胁下的孤立地中海森林储备大蛾类物种的生态漂移和定向群落变化。

长期数据对于了解生态群落随时间的变化很重要，但对于昆虫却很少。我们使用历史博物馆收藏品分析了此类变化。对于我们的研究区域（意大利东北部一个孤立的森林保护区），可以获取过去80年的数据。我们使用了300种蛾类物种的记录来分析灭绝风险是否与它们的体型或生态专业程度有关。通过对幼虫的食物隶属关系，生境偏好和北部分布限制进行分类来对专业化进行评分； 2）通过分析物种集合内随时间变化的功能分散度（FDis）来对专业化评分。我们的结果表明，局部灭绝的物种（平均翼展：37.0毫米）大于持久性物种（33.2毫米）或先前未记录的物种（30.7毫米），随着时间的推移，导致蛾类群落的平均翼展较小。一些生态过滤器似乎已针对较大的物种进行了选择。通过使用粗专业分类，我们没有观察到与当地灭绝风险的任何关系。但是，计算得出的12种物种特征的FDis随时间显着下降。我们得出的结论是，简单的分类系统可能无法反映社区范围内专业化的变化。FDis之类的多元方法可能会提供更深入的见解，因为它们反映了各种生态位。随着广泛的土地使用惯例的放弃，自然演替似乎已使蛾类群落向大量与森林有关的物种转变，导致FDis值降低。