Shifting baselines for species in chronic decline and assessment of conservation status. Are hazel dormice Muscardinus avellanarius Endangered?
Shifting baselines for species in chronic decline and assessment of conservation status. Are hazel dormice Muscardinus avellanarius Endangered?
复制标题
改变长期衰退物种的基线和保护状况评估。
DOI：
10.1002/2688-8319.12206
复制
发表时间：
2023
影响因子：
2.9
通讯作者：
Scopes E
中科院分区：
文献类型：
--
作者：
Scopes E
长期的数据有利于监测物种的保护状况。然而，对最近几个固定时期的人口变化的评估将受到“不断变化的基线”的制约，即在这一时期开始时，公认的人口标准已经比历史水平有所减少。国际自然保护联盟对保护威胁进行分类的红名单标准依赖于评估相对于数量阈值的下降，这通常是在10 年内衡量的，作为在不久的将来灭绝的可能性的迹象。相比之下，《欧洲栖息地指令》等法律框架要求各国为受保护物种实现并保持有利的保护地位，而国内的保护立法可以有更多样化的目标和机制，基于超出生物或数量标准的当地背景。我们探讨了与评估灭绝风险和保护状态相关的挑战，这些挑战源于英国对榛子睡鼠的长期监测数据的可获得性。国家睡鼠监测计划中统计的成年睡鼠数量正在持续下降，导致在1994年至2020年的27 年中总体下降了78%(95%可信区间=72%-84%)。如果观察到的每年5.7%的下降速度(95%可信区间=44.7%-6.8%)继续有增无减，睡鼠数量将从1994年到2034年下降90%。尽管如此，根据世界自然保护联盟的标准，该物种永远不会被归类为濒危物种，该标准规定在10 年内减少50%。虽然这种长期的下降可能并不意味着迫在眉睫的灭绝危险，但有理由将其列入更高的红色名单类别，这表明在国家范围内处于不利的保护状态。在证明这种长期衰退的基础上确定优先次序，可能会在物种恢复更有可能实现的时候，指导更有效的物种保护行动，而不是试图在物种最终“濒临灭绝”时逆转走向灭绝的旅程。
Long‐term data are beneficial for monitoring the conservation status of species. Assessments of population change over recent periods of fixed duration will, however, be subject to ‘shifting baselines’, where the accepted norm for the population at the start of the period already represents a reduction from historical levels. International Union for Conservation of Nature Red List criteria for categorizing conservation threat rely on assessing declines against quantitative thresholds, generally measured over 10 years, as indications of the likelihood of extinction in the near future. By contrast, legal frameworks such as the European Habitats Directive require states to achieve and sustain ‘Favourable Conservation Status’ for protected species, while domestic conservation legislation can have more diverse objectives and mechanisms, based on local contexts that extend beyond biological or quantitative criteria.We explore the challenges associated with assessing the risk of extinction and the conservation status that arise from the availability of long‐term monitoring data for hazel dormiceMuscardinus avellanariusin the United Kingdom.Numbers of adult dormice counted in the National Dormouse Monitoring Programme are in ongoing decline, amounting to an overall decline of 78% (95% confidence interval = 72%–84%) over 27 years, 1994–2020. If the observed annual rate of decline of 5.7% (95% CI = 4.7%–6.8%) were to continue unabated, dormouse counts would decline by >90% from 1994 to 2034. Despite this, the species would never be categorized as Endangered, under IUCN criteria, which specify a reduction of >50% within 10 years.While such chronic decline may not indicate imminent risk of extinction, justifying a higher Red List category, it is a demonstration of unfavourable conservation status at a national scale. Prioritization based on demonstration of such chronic declines might direct more effective action towards species conservation at a point when their recovery is more attainable, rather than attempting later to reverse a journey to the brink of extinction when the species is finally ‘Endangered’.