Ogasawara Matheus E K, Filoso Solange, Taniwaki Ricardo H, Ferraz Silvio F B
Department of Forest Sciences, "Luiz de Queiroz" College of Agriculture, University of São Paulo, Piracicaba, SP, Brazil; University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, Solomons, MD, United States.
University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, Solomons, MD, United States.
J Environ Manage. 2025 Aug;389:126095. doi: 10.1016/j.jenvman.2025.126095. Epub 2025 Jun 9.
Natural regeneration of riparian forest is vital for stream ecosystem health. However, there is limited evidence on the impact of passive restoration on key processes that sustain the functionality of small-order tropical streams. The objective of this study was to evaluate the ecological effectiveness of riparian forest restoration at enhancing the health of degraded agricultural streams in the neotropics. The study was conducted in 15 catchments in southeastern Brazil, using the space-for-time substitution design, where the 15 catchments were divided into three classes according to the age of their naturally regenerating riparian forests. We assessed the riparian forest structure, canopy cover, as well as stream channel attributes such as channel morphology, hydro-chemical conditions, and biological characteristics. Our results demonstrated that the structural complexity of riparian forests had a significantly higher forest structure and canopy cover compared to younger riparian areas. The large woody debris volume and abundance in the stream displayed an increase trend with the age of riparian forest and had important influence in channel morphology and, consequently, on the water quality, and primary production. We concluded that age of passive restoration was strongly linked to the riparian forest structure demonstrating that mature restored areas was responsible to improve physical, chemical and biological conditions of degraded streams. The results of this study can be used to guide and assist in the selection of strategies that ensure improvements in the health of degraded streams in the neotropics.
河岸森林的自然再生对溪流生态系统健康至关重要。然而，关于被动恢复对维持小流域热带溪流功能的关键过程的影响，证据有限。本研究的目的是评估河岸森林恢复对改善新热带地区退化农业溪流健康状况的生态有效性。该研究在巴西东南部的15个集水区进行，采用空间换时间替代设计，根据自然再生河岸森林的年龄将这15个集水区分为三类。我们评估了河岸森林结构、树冠覆盖率，以及溪流河道属性，如河道形态、水化学条件和生物特征。我们的结果表明，与较年轻的河岸区域相比，河岸森林的结构复杂性具有显著更高的森林结构和树冠覆盖率。溪流中大型木质碎屑的体积和丰度随着河岸森林年龄的增加呈上升趋势，对河道形态有重要影响，进而对水质和初级生产产生影响。我们得出结论，被动恢复的年限与河岸森林结构密切相关，表明成熟的恢复区域有助于改善退化溪流的物理、化学和生物条件。本研究结果可用于指导和协助选择确保改善新热带地区退化溪流健康状况的策略。
