Abstract The Nature Needs Half (NNH) movement aims to protect 50 % of the earth. That said protected area designation usually neglects freshwater ecosystems and biodiversity. We assessed protection of the surface area of lakes, length of river reaches, habitat area of fish and odonate species within the terrestrial-focused protected areas of Bhutan that meets NNH target. We categorised percentage protection into four progressive levels: (i) Below Aichi (≤16.9 %), (ii) Aichi and above (17–34.9 %), (iii) Near NNH (35–49.9 %) and (iv) NNH and above (≥50 %). Overall, we found both freshwater ecosystems and biodiversity were well represented within PAs of Bhutan. 1080 out of 1181 lakes had ‘NNH and above’ percentage surface area protection against only 99 with ‘below Aichi’ protection. Further, 1388 out of 3418 river reaches also had ‘NNH and above’ percentage river length protection, but this number was smaller than the number of reaches with ‘below Aichi’ protection (n = 1926). No fish or odonate species had ‘below Aichi’ percentage habitat area protection, but only one fish and no odonate species had ‘NNH and above’ protection. However, lakes and river reaches when considered by agro-ecological zone and river reach types respectively had no equitable and adequate protection. 14 of the 19 lakes within the five lower elevation agro-ecological zones had ‘below Aichi’ protection, while 1075 of the 1162 lakes inside alpine zone had ‘NNH and above’ protection. Similarly, the rarer river reach types had a greater number of the reaches with ‘below Aichi’ protection. More importantly, only 5 lakes within the five lower elevation agro-ecological zones had their whole surface area protected – in contrast to 1068 lakes within the alpine zone. Further, river reaches with shorter reach length and odonate species with smaller habitat area had lower percentage protection. Our findings imply a need for a priori consideration of freshwater ecosystems and biodiversity in PA designation even within NNH paradigm.

中文翻译：

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通过以陆地为重点的保护区及其对淡水生态系统和生物多样性保护的充分性，满足自然需求的一半：来自不丹的案例

摘要 大自然需要一半 (NNH) 运动旨在保护 50% 的地球。也就是说，保护区的指定通常会忽视淡水生态系统和生物多样性。我们评估了符合 NNH 目标的不丹陆地重点保护区内湖泊表面积、河段长度、鱼类和齿类物种的栖息地面积的保护情况。我们将百分比保护分为四个渐进级别：(i) 爱知以下 (≤16.9 %)，(ii) 爱知及以上 (17–34.9 %)，(iii) NNH 附近 (35–49.9 %) 和 (iv) NNH 和高于 (≥50%)。总体而言，我们发现淡水生态系统和生物多样性在不丹保护区内都有很好的体现。1181 个湖泊中的 1080 个具有“NNH 及以上”百分比的表面积保护，而只有 99 个具有“低于爱知”的保护。更多，3418 条河段中有 1388 条河段也有“NNH 及以上”百分比的河长保护，但这一数字小于“爱知以下”保护的河段数量（n = 1926）。没有鱼类或齿类物种的栖息地面积保护“低于爱知”百分比，但只有一种鱼类且没有齿类物种具有“NNH 及以上”的保护。然而，从农业生态区和河段类型分别考虑的湖泊和河段没有得到公平和充分的保护。5个低海拔农业生态区19个湖泊中有14个为“爱知以下”保护，高寒带内1162个湖泊中有1075个为“NNH及以上”保护。同样，较罕见的河流河段类型具有更多的“低于爱知”保护的河段。更重要的是，五个低海拔农业生态区中只有 5 个湖泊的整个表面积受到保护——而高山地带则有 1068 个湖泊。此外，河段较短的河段和栖息地面积较小的齿类物种的保护百分比较低。我们的发现意味着即使在 NNH 范式内，也需要在 PA 指定中先验考虑淡水生态系统和生物多样性。