Forest cover has been a pivotal indicator of biological conservation and carrying capacity for wildlife in forest ecoregions. Such a relationship underpins policies focused on the extension of protected lands. Here, we estimate aboveground biomass (AGB) as a proxy for habitat quality in seminatural rural patches and provide a comparison with approaches that only consider forest cover. We hypothesize that recommendations for biological conservation in agricultural landscapes are substantially improved if habitat quality is also taken into account, and thus consider the possibility of forest quality being modulated by land-use amount, type, and age. We assessed AGB in a densely farmed Brazilian region using a straightforward approach designed to be affordable at large scales, focusing on two expanding and contrasting land uses: sugarcane, and eucalyptus plantations. At a detailed scale, we confirmed through field surveys and AGB estimation using 3D-multispectral imagery (i.e., AGB = 0.842 × vegetation height^NDVI+1) that AGB variation could be predicted with forest degradation classes that are visually distinguishable with high-resolution images: 9.33 t ha⁻¹ (90% predictive intervals [PI] = [3.23, 26.97]) in regenerating fields (RF), 31.12 t ha⁻¹ (90% PI = [10.77, 89.90]) in pioneer woods (PW), and 149.04 t ha⁻¹ (90% PI = [51.59, 430.58]) in dense forests (DF). Applying these values to land units sampled across the study region, we found an average land use of 88.5%, together with 11.5% of land set aside for conservation, which reduced AGB to less than 4.2% of its potential (averages of 5.85 t ha⁻¹ in sugarcane-dominated areas and 6.56 t ha⁻¹ in eucalyptus-dominated areas, with secondary forests averaging 149.04 t ha⁻¹). This imbalance between forest cover and AGB resulted from forest quality decay, which was similarly severe among land-use types, ages, and extensions. Therefore, the shortage of trophic resources is likely more critical to wildlife than spatial limitations in vastly deforested tropical ecoregions, where AGB and carbon sinks can be more than doubled just by restoring forests in lands currently spared by agriculture.

中文翻译：

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热带农业景观中的自然植被生物量和森林质量维度

森林覆盖率是森林生态区生物保护和野生动物承载能力的关键指标。这种关系支撑着以扩大受保护土地为重点的政策。在这里，我们估计地上生物量（AGB）作为半自然农村斑块栖息地质量的代理，并与仅考虑森林覆盖的方法进行比较。我们假设，如果也考虑到栖息地质量，那么农业景观中生物保护的建议将得到显着改善，从而考虑森林质量受土地利用数量、类型和年龄调节的可能性。我们使用一种旨在大规模负担得起的直接方法评估了巴西农业密集地区的 AGB，重点关注两种不断扩大且对比鲜明的土地用途：甘蔗和桉树种植园。在详细尺度上，我们通过实地调查和使用 3D 多光谱图像的 AGB 估计（即 AGB = 0.842 × 植被高度^NDVI+1）确认，可以通过高分辨率图像在视觉上可区分的森林退化类别来预测 AGB 变化：再生林 (RF) 中 9.33  t  ha ⁻¹ (90% 预测区间 [PI] = [3.23, 26.97])，先锋林 (PW) 中 31.12  t  ha ⁻¹ (90% PI = [10.77, 89.90]) ，以及茂密森林 (DF) 中的149.04  t  ha ⁻¹ (90% PI = [51.59, 430.58])。将这些值应用于整个研究区域采样的土地单位，我们发现平均土地利用率为 88.5%，加上 11.5% 的土地预留用于保护，这将 AGB 减少到其潜力的不到 4.2%（平均为 5.85 吨  公顷）甘蔗为主的地区为 ^{-1 ，桉树为主的地区为 6.56} t  ha ^-1，次生林平均为 149.04  t  ha ^-1 )。森林覆盖率和 AGB 之间的这种不平衡是由森林质量衰退造成的，这种情况在土地利用类型、年龄和扩展范围中同样严重。因此，对于野生动物来说，营养资源的短缺可能比森林砍伐严重的热带生态区的空间限制更为严重，在热带生态区，只要在目前没有农业的土地上恢复森林，AGB和碳汇就可以增加一倍以上。