Commodity crops in biodiversity-rich production landscapes: Friends or foes? The example of cotton in the Mid Zambezi Valley, Zimbabwe

Mid Zambezi Valley, Zimbabwe, which is home to many emblematic African mammals, cotton production has historically been a major driver of land cover change. The collapse of cotton production in Zimbabwe over the last decade provides a unique opportunity to understand the linkages between the profitability of cotton and land-use changes in this multifunctional landscape. By re-visiting 141 households that had been surveyed in 2007 and combining this panel survey data with a land cover analysis and secondary data, we demonstrate that the decreasing profitability of cotton led to a shift from cotton farming (mean area per farm decreasing from 1.79 ± 2.05 ha in 2007 to 0.72 ± 0.90 ha in 2020) to livestock farming (mean number of cattle and goats per farm increasing several-fold between 2007 and 2020), resulting in drastic land cover changes. Indeed, open vegetation (including crops, fallows and grazing areas) expanded from 10 to 20% of the total land cover area between 2007 and 2020. Populations of wildlife species have declined drastically during this period, although this cannot be attributed solely to the observed changes in land cover. However, increasing human-wildlife conflicts are likely to threaten the long-term coexistence of people and wildlife in the area. We argue that commodity crops can be an opportunity for nature conservation, not only a threat, and that conservation needs to support a ‘living income’ for people coexisting with wildlife.

津巴布韦赞比西河中游谷地（Mid Zambezi Valley）栖息着诸多标志性非洲哺乳动物，历史上棉花生产曾是驱动该区域土地覆被变化的核心因素。过去十年间津巴布韦棉花产业的崩溃，为探究该多功能景观中棉花种植收益与土地利用变化之间的关联提供了独特契机。本研究通过回访2007年已接受过调查的141户农户，并将该面板调查数据与土地覆被分析数据及二手资料相结合，证实棉花种植收益的持续下滑促使农户从棉花种植（单农场平均种植面积从2007年的1.79±2.05公顷降至2020年的0.72±0.90公顷）转向畜牧养殖（单农场平均牛羊存栏量在2007至2020年间增长数倍），进而引发了剧烈的土地覆被变化。具体而言，2007至2020年间，开阔植被（涵盖农作物、休耕地与放牧区域）占总土地覆被面积的比例从10%升至20%。同期野生动物种群数量大幅下降，但这一现象不能仅归因于观测到的土地覆被变化。不过，不断升级的人兽冲突或会威胁该区域人类与野生动物的长期共存。本研究认为，商品作物种植并非仅对自然保护构成威胁，亦可成为保护工作的契机，且自然保护举措需为与野生动物共存的民众提供可持续生计支持。