Forest Science Department, Federal University of Lavras, Lavras, Minas Gerais, Brazil; brCarbon Serviços Ambientais, Piracicaba, São Paulo, Brazil.
Forest Science Department, Federal University of Lavras, Lavras, Minas Gerais, Brazil.
Sci Total Environ. 2023 Jul 15;882:163503. doi: 10.1016/j.scitotenv.2023.163503. Epub 2023 Apr 18.
Tropical montane forests (TMF) of the threatened Atlantic Forest hotspot play an important role in providing essential ecosystem services associated with hydrological regime and biodiversity conservation. However, important ecological patterns such as those related to the woody carbon biogeochemical cycle are not yet known for these forests, especially those located at high elevations (> 1500 m. a.s.l.). Herein, we used a dataset of 60 plots (2.4 ha) of old-growth TMF sampled along a high-elevation gradient (1500-2100 m a.s.l.) and monitored in two inventories (2011 and 2016) to better understand the patterns of carbon stock and uptake of these high-elevation forests and the related environmental (soil) and elevation controls. We found differences in the carbon stock along different elevation levels (120.36-170.4C.ton.ha) and a carbon accumulation trend over the period along the entire gradient. Thus, forest carbon gain (3.82-5.14 ton.ha.year) was greater than the carbon loss (2.1-3.4 ton.ha.year) and resulted in a positive productivity net. In other words, the TMF acted as a carbon sink, removing carbon from the atmosphere and storing it in woody tissues. Soil variables also exert significant influences on carbon stock and uptake (significative effects of phosphorus on carbon stock and of cation exchange capacity on carbon loss), driving such patterns in isolation or in interaction with elevation. Considering the high conservation degree of the TMF monitored, our results may be indicative of a similar trend in other similar forests, but which have gone through disturbances in the more recent past. These TMF fragments have a wide occurrence in the Atlantic Forest hotspot and may also be acting or will soon act as carbon sinks in improved conservation scenarios. Thus, these forests can play an essential role in conserving ecosystem services in the region and in mitigating climate changes.
受威胁的大西洋森林热点地区的热带山地森林（TMF）在提供与水文状况和生物多样性保护相关的重要生态系统服务方面发挥着重要作用。然而，对于这些森林，重要的生态模式，如与木质碳生物地球化学循环相关的模式，尚不清楚，特别是那些位于高海拔地区（> 1500 m. a.s.l.）的森林。在此，我们使用了一个数据集，该数据集由沿着高海拔梯度（1500-2100 m a.s.l.）采样的 60 个（2.4 公顷）原始 TMF 样地组成，并在两次清查（2011 年和 2016 年）中进行了监测，以更好地了解这些高海拔森林的碳储量和吸收模式以及相关的环境（土壤）和海拔控制。我们发现，碳储量在不同海拔水平（120.36-170.4C.ton.ha）上存在差异，并且在整个梯度上的整个时期都存在碳积累趋势。因此，森林碳增益（3.82-5.14 吨.公顷.年）大于碳损失（2.1-3.4 吨.公顷.年），导致净生产力为正。换句话说，TMF 充当了碳汇，从大气中吸收并储存碳。土壤变量也对碳储量和吸收有重要影响（磷对碳储量有显著影响，阳离子交换量对碳损失有显著影响），无论是单独作用还是与海拔相互作用，都驱动着这种模式。考虑到监测的 TMF 具有较高的保护程度，我们的结果可能表明其他类似森林也存在类似的趋势，但这些森林在最近的过去经历了干扰。这些 TMF 碎片在大西洋森林热点地区广泛存在，在改善的保护情景下，它们也可能或即将充当碳汇。因此，这些森林可以在该地区保护生态系统服务和减缓气候变化方面发挥重要作用。
