Abstract The Brazilian Amazon has 49.8 million hectares (Mha) of public forestlands not allocated by the federal or state governments to a specific tenure status: the so called undesignated public forests (UPF). Historically, these public forests have been vulnerable to land grabbers and land speculation. Here, we highlighted the imminent threat in UPF by quantifying their accumulated deforestation, all of which is illegal, for the period 1997–2018 and the potential illegal occupation. Based on the available government database, we found that 2.6 Mha of UPF had already been deforested by 2018 resulting in an emission of 1.2 billion tons of CO2 (Gt CO2). The accumulated deforestation was 5.4 times higher in federal UPF than in state UPF. Moreover, a total of 11.6 Mha of UPF have already been illegally registered as “private property” in the Brazilian Environmental Rural Registry (CAR), 70 % of these areas located in state UPF. If legalized as private proprieties, the carbon emissions resulting from additional deforestation will be roughly between 1.2 and 3.0 Gt CO2. The seriousness and precariousness of protection of Brazilian Amazon UPF, the rapid conversion of forests outside these areas and increased flexibility in land policies - calls for the immediate designation of these areas to some form of conservation, as to avoid irreparable damage to the world's largest rainforest.

中文翻译：

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无人区的无法无天：巴西亚马逊地区未指定的公共森林

摘要 巴西亚马逊有 4,980 万公顷 (Mha) 的公共林地，未由联邦或州政府分配给特定的使用权状态：即所谓的未指定公共森林 (UPF)。从历史上看，这些公共森林很容易受到土地掠夺者和土地投机的影响。在这里，我们通过量化 1997-2018 年期间累积的森林砍伐（所有这些都是非法的）和潜在的非法占领来强调 UPF 迫在眉睫的威胁。根据现有的政府数据库，我们发现到 2018 年，2.6 Mha 的 UPF 已经被砍伐，导致排放 12 亿吨二氧化碳 (Gt CO2)。联邦 UPF 的累计森林砍伐率是州 UPF 的 5.4 倍。此外，一共有11个。UPF 的 6 Mha 已经在巴西农村环境登记处 (CAR) 非法注册为“私有财产”，其中 70% 的地区位于 UPF 州。如果作为私有财产合法化，额外砍伐森林所产生的碳排放量将大约在 1.2 至 3.0 Gt CO2 之间。巴西亚马逊 UPF 保护的严重性和不稳定、这些地区以外的森林迅速转变以及土地政策的灵活性增加——要求立即将这些地区指定为某种形式的保护，以避免对世界上最大的热带雨林造成不可挽回的损害.