Serviços ecossistêmicos de carbono, composição e estrutura florestal em uma cronosequência de plantios de restauraçãodissertation
Аннотация: Forest restoration is a strategy widely used to reverse the current scenario of biodiversity loss, ecological functions degradation, and climate change intensification.However, it is necessary to certify whether the implemented forest restorations are effectively fulfilling these roles.In this context, we aimed to evaluate the potential of active forest restorations in accumulating carbon and reestablishing the ecological functions involved in this process, in addition to their contribution to the conservation of native plant species.First, we conducted a literature review to provide a national-level view of the aboveground carbon estimates in forests restored by different methods (active and passive restorations).We discussed trends and gaps in accumulated knowledge and the researches conducted in Brazil until the year 2019.The results show that Brazilian forest restorations present a high potential to contribute to carbon services regardless of the restoration method, but active restoration shows more promising results, at least over a period of 30 years.However, only 23% of the biomass and carbon studies in Brazil were conducted in active restorations.In addition, the relationship between the carbon stock of the restorations and their respective plant diversity was present in only 9% of the studies.Due to this bias in the accumulated knowledge, we aimed to provide robust estimates of the contribution of active restorations for carbon ecosystem services and the conservation of native flora.Thus, we evaluated these parameters in 16 restoration plantings aging from 5 to 30 years-old, to provide a temporal analysis of the results.Our estimates show that 30y-restorations can present carbon stocks similar to mature forest remnants.Although small individuals are numerically dominant regardless of the restorations' age, the results indicate that large plants hold the higher carbon stock before the end of the first decade after planting.Among the ecological groups, secondary species become more abundant than pioneers after 20 years, but carbon stock in secondary species is already similar to the pioneer ones earlier on the chronosequence.We observed that the dynamics established in these communities is marked by the transition among plants from vi different size classes and ecological groups.We can infer that the observed patterns promote the successional trajectory and, possibly, the perpetuation of the processes involved in the carbon accumulation over time.Although the outcomes related to structure, functional groups, and carbon stocks of the restorations are quite positive, their role in plant conservation could be better developed.Thus, although restoration plantations contribute to the maintenance of floristic diversity in anthropized regions, their role in conserving priority plant species is less remarkable.However, with the presence of different species relevant to the ecosystem functioning and the provision of carbon ecosystem services within the restorations, we assume that active restorations embedded in agricultural landscapes provide a huge opportunity to promote synergistic outcomes.On the other hand, this potential is not fully employed, as priority species for conservation, especially those threatened with extinction and endemic, are not frequent or abundant in these forests.Finally, we provide guidelines that could overcome the identified limitations and maximize the multifunctional character of the active restorations, ensuring that the objectives foreseen in the planning of these actions are effectively achieved.
Год издания: 2021
Авторы: Fernando Ravanini Gardon
Ключевые слова: Forest ecology and management, Conservation, Biodiversity, and Resource Management, Ecology and Vegetation Dynamics Studies
Открытый доступ: gold