ABSTRACT
The contribution of working forests to tropical conservation and development depends upon the maintenance of ecological integrity under ongoing land use. Assessment of ecological integrity requires an understanding of the structure, composition, and function and major drivers that govern their variability. Working forests in tropical river floodplains provide many goods and services, yet the data on the ecological processes that sustain these services is scant. In flooded forests of riverside Amazonian communities, we established 46 0.1-ha plots varying in flood duration, use by cattle and water buffalo, and time since agricultural abandonment (30-90 yr). We monitored three aspects of ecological integrity (stand structure, species composition, and dynamics of trees and seedlings) to evaluate the impacts of different trajectories of livestock activity (alleviation, stasis, and intensification) over nine years. Negative effects of livestock intensification were solely evident in the forest understory, and plots alleviated from past heavy disturbance increased in seedling density but had higher abundance of thorny species than plots maintaining low activity. Stand structure, dynamics, and tree species composition were strongly influenced by the natural pulse of seasonal floods, such that the defining characteristics of integrity were dependent upon flood duration (3-200 d). Forests with prolonged floods ≥ 140 d had not only lower species richness but also lower rates of recruitment and species turnover relative to forests with short floods <70 d. Overall, the combined effects of livestock intensification and prolonged flooding hindered forest regeneration, but overall forest integrity was largely related to the hydrological regime and age. Given this disjunction between factors mediating canopy and understory integrity, we present a subset of metrics for regeneration and recruitment to distinguish forest condition by livestock trajectory. Although our study design includes confounded factors that preclude a definitive assessment of the major drivers of ecological change, we provide much-needed data on the regrowth of a critical but poorly studied ecosystem. In addition to its emphasis on the dynamics of tropical wetland forests undergoing anthropogenic and environmental change, our case study is an important example for how to assess of ecological integrity in working forests of tropical ecosystems.
Subject(s)
Floods , Forests , Livestock , Rivers , Animals , Brazil , Ecosystem , SeasonsABSTRACT
Tropical rainforest regions have large hydropower generation potential that figures prominently in many nations' energy growth strategies. Feasibility studies of hydropower plants typically ignore the effect of future deforestation or assume that deforestation will have a positive effect on river discharge and energy generation resulting from declines in evapotranspiration (ET) associated with forest conversion. Forest loss can also reduce river discharge, however, by inhibiting rainfall. We used land use, hydrological, and climate models to examine the local "direct" effects (through changes in ET within the watershed) and the potential regional "indirect" effects (through changes in rainfall) of deforestation on river discharge and energy generation potential for the Belo Monte energy complex, one of the world's largest hydropower plants that is currently under construction on the Xingu River in the eastern Amazon. In the absence of indirect effects of deforestation, simulated deforestation of 20% and 40% within the Xingu River basin increased discharge by 4-8% and 10-12%, with similar increases in energy generation. When indirect effects were considered, deforestation of the Amazon region inhibited rainfall within the Xingu Basin, counterbalancing declines in ET and decreasing discharge by 6-36%. Under business-as-usual projections of forest loss for 2050 (40%), simulated power generation declined to only 25% of maximum plant output and 60% of the industry's own projections. Like other energy sources, hydropower plants present large social and environmental costs. Their reliability as energy sources, however, must take into account their dependence on forests.
Subject(s)
Climate Change , Conservation of Natural Resources/statistics & numerical data , Rain , Renewable Energy/statistics & numerical data , Rivers , Trees , Brazil , Computer Simulation , Models, Theoretical , Public Policy , SeasonsABSTRACT
Land-use regulations are a critical component of forest governance and conservation strategies, but their effectiveness in shaping landholder behaviour is poorly understood. We conducted a spatial and temporal analysis of the Brazilian Forest Code (BFC) to understand the patterns of regulatory compliance over time and across changes in the policy, and the implications of these compliance patterns for the perceived costs to landholders and environmental performance of agricultural landscapes in the southern Amazon state of Mato Grosso. Landholdings tended to remain in compliance or not according to their status at the beginning of the study period. The perceived economic burden of BFC compliance on soya bean and beef producers (US$3-5.6 billion in net present value of the land) may in part explain the massive, successful campaign launched by the farm lobby to change the BFC. The ecological benefits of compliance (e.g. greater connectivity and carbon) with the BFC are diffuse and do not compete effectively with the economic benefits of non-compliance that are perceived by landholders. Volatile regulation of land-use decisions that affect billions in economic rent that could be captured is an inadequate forest governance instrument; effectiveness of such regulations may increase when implemented in tandem with positive incentives for forest conservation.
Subject(s)
Agriculture/economics , Conservation of Natural Resources/economics , Environmental Policy , Forestry/legislation & jurisprudence , Agriculture/legislation & jurisprudence , Animals , Brazil , Carbon/analysis , Cattle , Computer Simulation , Conservation of Natural Resources/legislation & jurisprudence , Ecosystem , Forestry/economics , Meat/economics , Glycine max/economics , Spatial Analysis , TreesABSTRACT
Community forestry initiatives have been shown to reduce rural poverty while promoting the conservation and sustainable use of forests. However, a number of challenges face communities wanting to initiate or maintain formal, community-based forest management. Through a grounded theory approach, this paper uses three case studies of community forest management models in the eastern Amazon to create a framework showing challenges faced by communities at different phases of formal management. The framework shows that, in the development phase, four root problems (land ownership, knowledge acquisition, community organization, and adequate capital) need to be addressed to obtain legal management permission. With this permission in hand, further challenges to operationalization are presented (deterring illegal loggers, maintaining infrastructure, obtaining necessary managerial skills and accessing markets). The interrelatedness of these challenges emphasizes that all challenges need to be addressed in a holistic manner for communities to maintain a profitable and self-sufficient operation. This contradicts current development approaches that only address part of this framework. The framework proposed here can be used as a starting point for community forestry initiatives in other regions.