Markl Gregor, Hinneberg Heiko, Tarmann Gerhard
Department of Geosciences University of Tübingen Tübingen Germany.
University of Applied Forest Sciences Rottenburg Rottenburg a. N. Germany.
Ecol Evol. 2022 Sep 12;12(9):e9291. doi: 10.1002/ece3.9291. eCollection 2022 Sep.
The decline of biodiversity in general and of insect diversity in particular has been recognized as a major environmental problem in recent years. In this study, we analyze the distribution and the decline of populations of forester moths of the genus in Central Europe since 1950 as a type example of the loss of grassland biodiversity, and discuss potential drivers causing this decline. Based on the extensive work in museums and private collections, a literature review and own observations, and including data as far back as 1834, this genus helps to understand the deeper reasons of insect population and biodiversity decline, as the well investigated six Central European species cover a broad range of extensive grassland habitats (fens to low-production grassland and xerothermic steppes) from low altitudes to high alpine meadows. Therefore, they monitor processes relevant also to other, less investigated grassland species. Although there are differences in research intensity over time and in different natural areas, we show that in the whole of Central Europe, the populations of all six investigated species broke down massively in the past decades, both in terms of number of populated habitats (about 400 recorded localities after the year 2000 compared with a total number of about 1600 at all times, cumulated for all six species) and in terms of number of individuals. On the other hand, some natural areas on a regional scale have more or less maintained their populations, due to conservative land use and due to the early implementation of conservation and protection management plans. The reasons of decline are manifold and monitored in detail by the different species with their different habitat requirements. They comprise (1) loss of habitats due to land use changes (both intensification and abandonment), (2) loss of habitats due to urbanization and construction work, (3) loss of habitat networks to cope with small-scale extinction events, (4) more intensive growth of grass at the expense of other plants in otherwise undisturbed habitats due to fertilization through the air (increased nitrogen levels due to human activities) and (5) use of pesticides.
近年来，生物多样性的普遍下降，尤其是昆虫多样性的下降，已被公认为一个主要的环境问题。在本研究中，我们分析了自1950年以来中欧地区 属林蛾种群的分布及减少情况，以此作为草地生物多样性丧失的一个典型例子，并讨论导致这种减少的潜在驱动因素。基于在博物馆和私人收藏中的大量工作、文献综述以及自身观察，包括可追溯到1834年的数据，该属有助于理解昆虫种群和生物多样性下降的深层原因，因为经过充分研究的六个中欧物种涵盖了从低海拔到高海拔草甸的广泛的粗放草地栖息地（沼泽地到低产草地和干热草原）。因此，它们也监测与其他较少研究的草地物种相关的过程。尽管随着时间推移以及在不同自然区域研究强度存在差异，但我们表明，在整个中欧地区，过去几十年中，所有六个被调查的 物种的种群数量在栖息地数量（2000年后记录的约400个地点，与所有六个物种累计的约1600个地点总数相比）和个体数量方面都大幅减少。另一方面，由于土地利用保守以及早期实施了保护管理计划，一些区域尺度上的自然区域或多或少维持了它们的 种群数量。下降的原因是多方面的，不同物种因其不同的栖息地需求对此进行了详细监测。这些原因包括：（1）土地利用变化（集约化和弃耕）导致的栖息地丧失；（2）城市化和建设工程导致的栖息地丧失；（3）应对小规模灭绝事件的栖息地网络丧失；（4）在原本未受干扰的栖息地中，由于空气施肥（人类活动导致氮水平增加），以其他植物为代价的草生长更加旺盛；（5）农药的使用。
