摘要
The Anthropocene is marked by twin crises:climate change and biodiversity loss.Climate change has tended to dominate the headlines,reflecting,in part,the greater complexity of the biodiversity crisis.Biodiversity itself is a difficult concept.Land plants dominate the global biomass and terrestrial arthropods probably dominate in terms of numbers of species,but most of the Tree of Life consists of single-celled eukaryotes,bacteria,and archaea.Wild plants provide a huge variety of products and services to people,ranging from those that are species-specific,such as food,medicine,and genetic resources,to many which are partly interchangeable,such as timber and forage for domestic animals,and others which depend on the whole community,but not on individual species,such as regulation of water supply and carbon sequestration.The use of information from remote sensing has encouraged a simplified view of the values of nature's contributions to people,but this does not match the way most people value nature.We can currently estimate the proportion of species threatened by human impacts only for a few well-assessed groups,for which it ranges from 14%(birds)to 63%(cycads).Less than 8%of land plants have been assessed,but it has been estimated that 30e44%are threatened,although there are still few(0.2%)well-documented extinctions.Priorities for improving protection of biodiversity include:improving the inventory,with surveys focused on geographical areas and taxonomic groups which are under-collected;expanding the protected area system and its representativeness;controlling overexploitation;managing invasive species;conserving threatened species ex situ;restoring degraded ecosystems;and controlling climate change.The Convention on Biological Diversity(CBD)COP15 and the United Nations Framework Convention on Climate Change(UNFCCC)COP26 meetings,both postponed to 2021,will provide an opportunity to address both crises,but success will require high ambition from all participants.
