Abstract

The Monte, one of the main arid regions in Argentina, is affected by degradation processes that impact the biological communities. Arthropods are the most diverse component of the Monte fauna and play important roles in several ecosystem processes. The study of interactions between native plants and arthropods, two key elements of the Monte biodiversity, contributes to our understanding of how this ecosystem functions. Our objective was to compare the plant-dwelling arthropod assemblages associated with representative shrub species of the southern Monte and to analyse the relationship between plant architecture and the assemblage structure. We sampled arthropods using the beating method on three evergreen shrub species (Chuquiraga avellanedae, Schinus johnstonii and Larrea divaricata) at six sites during two consecutive spring seasons. We recorded shrub height, canopy area, volume and an index of canopy openness. Our results showed that native shrub species host different arthropod assemblages, partially explained by both the shrub species identity and shrub architecture (mainly canopy openness). The arthropod assemblage that lives in S. johnstonii showed the highest diversity, probably related to the plant’s intermediate canopy openness, which may determine favourable microhabitats that provide protection against adverse climatic conditions and predators. The assemblage in C. avellanedae had the lowest diversity. The closed canopy of C. avellanedae could be beneficial for a few very abundant taxa that dominate the assemblage associated with it.

Implications for Insect Conservation

Our results show that these native shrubs support a wide range of arthropod taxa and guilds, contributing to maintaining the biodiversity in the southern Monte.

中文翻译：

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阿根廷巴塔哥尼亚南部蒙特的本地灌木及其对节肢动物多样性的重要性

摘要

蒙特是阿根廷主要的干旱地区之一，受到生物群落退化过程的影响。节肢动物是蒙特动物区系中最多样化的组成部分，在多种生态系统过程中发挥着重要作用。对本地植物和节肢动物之间的相互作用的研究，这是Monte生物多样性的两个关键要素，有助于我们了解该生态系统的功能。我们的目的是比较与南部蒙特州代表性灌木物种相关的植物栖身节肢动物组合，并分析植物结构与组合结构之间的关系。我们使用拍打法对3种常绿灌木树种（Chuquiraga avellanedae，Schinus johnstonii和连续两个春季在六个地点的Larrea divaricata）。我们记录了灌木的高度，冠层面积，体积和冠层开放度指数。我们的结果表明，本地灌木物种具有不同的节肢动物组合，部分由灌木物种的身份和灌木结构（主要是树冠开放性）解释。居住在约翰逊链球菌中的节肢动物组合显示出最高的多样性，这可能与植物的中间冠层开放度有关，这可能决定了有利的微生境，为抵御不利的气候条件和食肉动物提供了保护。C. avellanedae中的组合多样性最低。C. avellanedae的封闭的树冠 对于支配其相关组合的一些非常丰富的分类单元可能是有益的。

对昆虫保护的意义

我们的结果表明，这些原生灌木支持各种节肢动物类群和行会，有助于维持蒙特州南部的生物多样性。