We conducted a 3-yr cropping systems experiment in central Pennsylvania, USA, to determine the effects of initial cover crop species, tillage and resulting environmental variables on the activity–density (A–D), species richness, community composition and guild composition of carabid beetles (Carabidae: Coleoptera) during the transition from conventional to organic production. We compared four systems in a factorial combination of a mixed perennial sod (timothy, Phleum pratense L.) and legumes (red clover, Trifolium pratense L.) or annual cereal grain (cereal rye, Secale cereale L.) followed by a legume (hairy vetch, Vicia villosa Roth) as initial cover crops, and soil management using full tillage (moldboard plow) or reduced tillage (chisel plow) implemented in soybeans followed by maize in the subsequent year. The experiment was established twice, first in autumn 2003 (S1) and again in autumn 2004 (S2) in an adjacent field, in a randomized complete-block design with four replicates in each Start. We collected a total of 2181 adult carabid beetles. Approximately 65% of the carabid beetles collected were from six species. Indicator Species Analysis showed that several carabid species were indicative of treatment, e.g., Poecilus chalcites was a strong indicator for treatments with an initial cereal rye cover crop. Eleven environmental variables explained variation in carabid A–D, richness and the A–D of species categorized by size class and dominant trophic behavior, respectively, but varied in significance and direction among guilds. Soil moisture was a significant effect for total carabid A–D in both S1 and S2. Redundancy analyses revealed some similar and some idiosyncratic responses among informative species for the cover crop×tillage treatments through the 3-yr rotation. The most consistent factors that distinguished species assemblages among years and treatments were the number and intensity of soil disturbances and perennial weed density. The consistent occurrence of soil disturbance indicators in multivariate analyses suggests that future studies that aim to compare the effects of nominal soil management treatments on carabid beetles and other soil-associated arthropods should quantify frequency and intensity of disturbance associated with crop management practices.

中文翻译：

---

Carabid 甲虫（鞘翅目：Carabidae）在向有机管理过渡的过程中对饲料和草料系统中的土壤管理实践有不同的反应

我们在美国宾夕法尼亚州中部进行了一项为期 3 年的种植系统试验，以确定初始覆盖作物种类、耕作和由此产生的环境变量对活动密度 (A-D)、物种丰富度、群落组成和公会组成的影响。甲虫（Carabidae：鞘翅目）在从常规生产到有机生产的过渡过程中。我们比较了混合多年生草皮（蒂莫西，禾本科植物L.）和豆类（红三叶草，车轴草L.）或一年生谷物（谷物黑麦，黑麦L.) 后面是豆科植物（多毛紫云英，紫花苜蓿Roth）作为最初的覆盖作物，并在随后一年在大豆和玉米中实施全耕（犁板犁）或减少耕作（凿犁）的土壤管理。该实验建立了两次，第一次是在 2003 年秋季 (S1)，然后是 2004 年秋季 (S2)，在相邻的田间进行，采用随机完整区组设计，每个开始有四个重复。我们共收集了 2181 只成年甲虫。收集到的大约 65% 的甲虫来自六个物种。指标物种分析表明，几种鲶鱼物种表明治疗，例如，Poecilus 方解石是初始谷物黑麦覆盖作物处理的有力指标。11 个环境变量分别解释了按大小等级和优势营养行为分类的物种的鲶鱼 A-D、丰富度和 A-D 的变化，但在行会之间的意义和方向各不相同。土壤水分对 S1 和 S2 中的总 carabid A-D 有显着影响。通过 3 年轮作，冗余分析揭示了信息物种对覆盖作物×耕作处理的一些相似和一些特殊的反应。区分年份和处理之间物种组合的最一致的因素是土壤扰动的数量和强度以及多年生杂草密度。