Habitat amount, not patch size and isolation, drives species richness of macro‐moth communities in countryside landscapes

Aim: Our aim is to test whether species richness patterns are best explained by the effect of the total amount of habitat within the landscape, or instead by a combination of patch size and patch isolation effects. To this end, we jointly contrast the habitat amount hypothesis and countryside biogeography with patch size and isolation concepts from island biogeography. Location: Three multi-habitat landscapes in Peneda-Gerês National Park, NW Portugal. Taxon: Macro-moths (Lepidoptera). Methods: Light-trapping using a semi-nested design at 84 fixed sites which were each repeatedly sampled six times. Results: Autocovariate models show that sampling sites with a higher number of forest and meadow macro-moth species (alpha diversity) were surrounded by a higher amount of forest and meadow habitat, respectively within a 160 and 320 m radius (scale of effect). These top-ranked models, containing only habitat amount as a significant variable, had lower AIC than models (only) containing patch size and/or isolation. Complementary to this, the countryside species-area relationship (SAR) model outperforms the classic SAR model, so that the effective area of habitat explains landscape species richness (gamma diversity) across spatial scales (beta diversity) better than the classic SAR. Specifically, we show that forest macro-moths have a higher spatial turnover than meadow macro-moths and that, on average, there are more species in forest than in meadow habitat. Main conclusions: The habitat amount hypothesis predicts alpha species richness in multi-habitat landscapes better than do patch size and isolation while the countryside SAR predicts beta and gamma diversity better than the classic SAR. We suggest that evidence is mounting to revise the application of the classical approaches of island biogeography and metapopulation theory to conservation biogeography.

研究目的：本研究旨在检验物种丰富度格局的最优解释变量，究竟是景观内栖息地总量效应，还是斑块面积与斑块隔离效应的共同作用。为此，我们将栖息地总量假说（habitat amount hypothesis）与乡村生物地理学（countryside biogeography）理论，同岛屿生物地理学中的斑块面积、隔离度概念进行联合对比分析。
研究区域：葡萄牙西北部佩内达-热尔国家公园（Peneda-Gerês National Park）内的3处多栖息地景观。
研究类群：大型蛾类（鳞翅目，Lepidoptera）。
研究方法：采用半嵌套设计的灯光诱捕法，在84个固定样地开展采样，每个样地重复采样6次。
研究结果：自协方差模型（autocovariate models）显示，森林与草地大型蛾类的α多样性（alpha diversity）较高的采样样地，其周边160米和320米半径范围内（效应尺度）的森林与草地栖息地占比分别更高。仅以栖息地总量作为显著变量的最优模型，其赤池信息准则（Akaike Information Criterion, AIC）值低于仅包含斑块面积和/或隔离度的模型。此外，乡村种-面积关系（countryside species-area relationship, SAR）模型的表现优于经典种-面积关系（species-area relationship, SAR）模型，即栖息地有效面积对跨空间尺度（β多样性，beta diversity）下的景观物种丰富度（γ多样性，gamma diversity）的解释力，优于经典种-面积关系模型。具体而言，森林大型蛾类的空间周转速率高于草地大型蛾类，且平均而言森林生境中的物种数多于草地生境。
主要结论：相较于斑块面积与隔离度，栖息地总量假说能更优地解释多栖息地景观中的α物种丰富度；而乡村种-面积关系模型则比经典种-面积关系模型更能准确预测β多样性与γ多样性。本研究表明，越来越多的证据支持修订岛屿生物地理学与集合种群理论的经典方法在保护生物地理学中的应用范式。

搜集汇总

背景与挑战

背景概述

该数据集基于葡萄牙Peneda-Gerês国家公园的三个多栖息地景观，通过光诱捕方法收集了84个采样点的大型蛾群落数据，旨在验证栖息地数量假说。研究结果表明，栖息地数量是预测α物种丰富度的关键因素，优于斑块大小和隔离度的影响，同时乡村物种-面积关系模型在解释β和γ多样性方面表现更佳。数据集包含斑块大小、隔离度、栖息地数量及物种-面积关系模型的具体测量数据，支持对栖息地破碎化和生物多样性保护的进一步分析。