Centre for Environmental Management (IB 67), University of the Free State, Bloemfontein, South Africa.
Section for Animal Ecology, Global Change and Sustainable Development, KU Leuven, Leuven, Belgium.
Nat Ecol Evol. 2020 Jun;4(6):815-819. doi: 10.1038/s41559-020-1177-7. Epub 2020 Apr 6.
One proposal for the Convention on Biological Diversity's post-2020 strategic plan is 'zero loss' of natural habitats. However, the feasibility of zero loss was questioned during the Trondheim Conference for Biodiversity, and it was suggested that biodiversity losses are instead balanced by compensatory efforts (that is, 'no net loss'). The focus on net outcomes is echoed by separate calls for a global mitigation hierarchy to deliver no net biodiversity loss and accommodate both conservation and development goals. Here we show that 'no net loss' is not the same as 'zero loss'. We use a delayed differential model of nonlinear habitat dynamics to demonstrate how applying the mitigation hierarchy for net biodiversity outcomes will lead to biodiversity declines by midcentury. Delayed compensation of human impacts reduces ecological resilience and causes prolonged biodiversity losses. These effects are greatest when impacts are large and compensation delays are long. Our results support the use of fixed targets, rather than net outcomes, as part of the post-2020 biodiversity framework.
一项关于生物多样性公约 2020 年后战略计划的提案是实现自然生境“零损失”。然而，在特隆赫姆生物多样性会议上，零损失的可行性受到质疑，有人建议通过补偿努力（即“无净损失”）来平衡生物多样性损失。对净结果的关注得到了另一个呼吁的呼应，即建立一个全球缓解层次结构，以实现无净生物多样性损失，并兼顾保护和发展目标。在这里，我们表明“无净损失”与“零损失”并不相同。我们使用非线性生境动态的时滞微分模型来证明，应用净生物多样性结果的缓解层次结构将如何导致到本世纪中叶生物多样性下降。人类影响的延迟补偿降低了生态弹性，并导致生物多样性的长期损失。当影响较大且补偿延迟较长时，这些影响最大。我们的结果支持在 2020 年后生物多样性框架中使用固定目标，而不是净结果。
