Freie Universität Berlin, Institut für Biologie, Berlin, Germany.
Berlin-Brandenburg Institute of Advanced Biodiversity Research (BBIB), Berlin, Germany.
Mol Ecol. 2021 Oct;30(19):4899-4912. doi: 10.1111/mec.16090. Epub 2021 Aug 5.
Southern Amazonia is currently experiencing extensive land use change from forests to agriculture caused by increased local and global demand for agricultural products. However, little is known about the impacts of deforestation and land use change on soil biota. We investigated two regions in southern Amazonia (rainforest and Savannah/Cerrado biomes), analysing soil biota community turnover based on 16S (Archaea and Bacteria) and 18S rRNA genes (Eukaryotes, including Fungi, Protists and Animalia) and correlating them with soil chemistry and land use intensity. We found that soil biota community structure is driven by land use change in both Cerrado and rainforest. Crop fields approximatively doubled the richness of soil Archaea, Bacteria and Protists. We propose that crop systems not only increase soil pH and fertility, but also create continued disturbance (crop seasons) that stimulates soil diversity, as predicted by the dynamic equilibrium model (DEM) and the intermediate disturbance hypothesis (IDH). Even though agricultural fields had higher soil biota richness, some taxa were suppressed by agriculture (6/31 operational taxonomic units of Archaea, 245/1790 of Bacteria, 12/74 of Animalia, 20/144 of Fungi and 25/310 of Protists). Consequently, land use change in this region should proceed with caution. In the southern Amazonia region of Brazil, current laws require farmers to keep 20%-80% pristine vegetation areas on their property. Our data support the relevance of this law: since there are unique soil taxa under native vegetation, keeping these pristine areas adjacent to the agricultural fields should maximize soil biodiversity protection in these regions.
南亚马逊地区目前正经历着森林向农业的大规模土地利用变化，这是由于当地和全球对农产品需求的增加所导致的。然而，对于森林砍伐和土地利用变化对土壤生物群的影响知之甚少。我们调查了南亚马逊地区的两个地区（雨林和热带稀树草原/塞拉多生物群落），分析了基于 16S（古菌和细菌）和 18S rRNA 基因（真核生物，包括真菌、原生动物和动物）的土壤生物群群落更替，并将其与土壤化学和土地利用强度相关联。我们发现，土地利用变化是塞拉多和雨林土壤生物群结构的驱动因素。农田大约使土壤古菌、细菌和原生动物的丰富度增加了一倍。我们提出，与动态平衡模型（DEM）和中度干扰假说（IDH）预测的一样，作物系统不仅增加了土壤 pH 值和肥力，还通过作物季节持续干扰刺激了土壤多样性。尽管农业领域的土壤生物群具有更高的丰富度，但一些分类群受到农业的抑制（古菌的 6/31 个操作分类单元、细菌的 245/1790 个、动物的 12/74 个、真菌的 20/144 个和原生动物的 25/310 个）。因此，该地区的土地利用变化应该谨慎进行。在巴西南亚马逊地区，现行法律要求农民在其土地上保留 20%-80%的原始植被区。我们的数据支持这项法律的相关性：由于在原始植被下存在独特的土壤分类群，因此在农业用地附近保留这些原始区域应该可以最大程度地保护这些地区的土壤生物多样性。
