Mark Schulze

Technical Challenges to Sustainable Forest Management in Concessions on Public Lands in the Brazilian Amazon

Abstract Brazils new Public Forests law authorizes concessions-based industrial forest management in Amazonian national public forests covering 13 million hectares within the next decade, expanding eventually to 50 million hectares or an area, the size of Spain. Both logging and conservation industries have promoted concessions management as a solution to chaotic land tenure and widespread illegal logging in the Brazilian Amazon. Here we evaluate technical aspects of actually managing concession forests at the proposed spatial scale and time-frame. The current best-practices logging system in Amazonia, reduced-impact logging (RIL), is not widely employed by the logging industry and does not ensure sustained-yield timber production in the absence of silvicultural practices promoting growth and regeneration in logged stands. Current legislated logging standards—for example, maximum per unit area harvest intensity, minimum diameter felling limit, seed tree retention rate, and 25- to 35-year cutting cycles—guarantee commercial depletion or extirpation of many high-value timber species over multiple cutting cycles. An estimated 10,450 field technicians will need to be trained in best-practices forest management within the next decade in order to adequately staff the proposed Brazilian Forest Service whose mandate it will be to oversee this vast undertaking, to expand field staff of the Brazilian Institute of the Environment and Renewable Natural Resources (IBAMA) and of state environmental agencies whose responsibility it is to regulate forest management, and to provide trained workers for the logging industry operating within concessions. What “sustainable forest management” means to various audiences must be clarified, and common ground identified among these audiences specifically addressing demands that will be made on national forests. Forest management systems integrating both operational and silvicultural practices must then be developed according to regional and local forest conditions. This will require renewed investment in technical research and capacity building, serving both the logging industry and government agencies charged with ensuring industry adherence to national forest legislation.

Spatial models reveal the microclimatic buffering capacity of old-growth forests

Spatial models of under-canopy temperature show that old-growth forests are cooler in spring months than mature forest plantations. Climate change is predicted to cause widespread declines in biodiversity, but these predictions are derived from coarse-resolution climate models applied at global scales. Such models lack the capacity to incorporate microclimate variability, which is critical to biodiversity microrefugia. In forested montane regions, microclimate is thought to be influenced by combined effects of elevation, microtopography, and vegetation, but their relative effects at fine spatial scales are poorly known. We used boosted regression trees to model the spatial distribution of fine-scale, under-canopy air temperatures in mountainous terrain. Spatial models predicted observed independent test data well (r = 0.87). As expected, elevation strongly predicted temperatures, but vegetation and microtopography also exerted critical effects. Old-growth vegetation characteristics, measured using LiDAR (light detection and ranging), appeared to have an insulating effect; maximum spring monthly temperatures decreased by 2.5°C across the observed gradient in old-growth structure. These cooling effects across a gradient in forest structure are of similar magnitude to 50-year forecasts of the Intergovernmental Panel on Climate Change and therefore have the potential to mitigate climate warming at local scales. Management strategies to conserve old-growth characteristics and to curb current rates of primary forest loss could maintain microrefugia, enhancing biodiversity persistence in mountainous systems under climate warming.

Forest certification in Amazonia: standards matter

Forest Stewardship Council (FSC) certification promises international consumers that ‘green-label’ timber has been logged sustainably. However, recent research indicates that this is not true for ipe (Tabebuia spp.), currently flooding the US residential decking market, much of it logged in Brazil. Uneven or non-application of minimum technical standards for certification could undermine added value and eventually the certification process itself. We examine public summary reports by third-party certifiers describing the evaluation process for certified companies in the Brazilian Amazon to determine the extent to which standards are uniformly applied and the degree to which third-party certifier requirements for compliance are consistent among properties. Current best-practice harvest systems, combined with Brazilian legal norms for harvest levels, guarantee that no certified company or community complies with FSC criteria and indicators specifying species-level management. No guidelines indicate which criteria and indicators must be enforced, or to what degree, for certification to be conferred by third-party assessors; nor do objective guidelines exist for evaluating compliance for criteria and indicators for which adequate scientific information is not yet available to identify acceptable levels. Meanwhile, certified companies are expected to monitor the long-term impacts of logging on biodiversity in addition to conducting best-practice forest management. This burden should reside elsewhere. We recommend a clarification of ‘sustained timber yield’ that reflects current state of knowledge and practice in Amazonia. Quantifiable verifiers for best-practice forest management must be developed and consistently employed. These will need to be flexible to reflect the diversity in forest structure and dynamics that prevails across this vast region. We offer suggestions for how to achieve these goals.

Big-leaf mahogany Swietenia macrophylla population dynamics and implications for sustainable management

Summary 1. The impacts of selective harvesting in tropical forests on population recovery and future timber yields by high-value species remain largely unknown for lack of demographic data spanning all phases of life history, from seed to senescence. In this study, we use an individual-based model parameterized using 15 years of annual census data to simulate population dynamics of big-leaf mahogany Swietenia macrophylla King in southeast Amazonia in response to multiple harvests and in the absence of harvesting. 2. The model is based on regression equations of stem diameter growth, mortality, and fruit production estimated as a function of stem diameter and prior growth; it includes functions for germinating seeds, growing trees from seedling to adult senescence, producing seeds, and creating disturbances at specified spatial scales and return intervals, including logging. We simulate six harvest scenarios by varying the minimum diameter cutting limit (60 cm, 80 cm) and the retention rate requirement (20%, 40% and 60% commercial population retained). 3. Without logging, simulated populations grew over 100 years by 182% from observed densities, indicating that one or more parameters in the model may overestimate long-term demographic rates on this landscape. However, 100-year densities did not far exceed values reported from forests across this region, and other modelled demographic parameters resembled observed behaviours. 4. Under current harvest regulations for mahogany in Brazil (60 cm minimum diameter cutting limit, 20% commercial-sized tree retention rate, minimum 5 commercial-sized trees 100 ha � 1 retained after harvest, 30-year cutting cycle), commercial densities at the study site would decline from 39� 7t o 11 � 3 trees 100 ha � 1 before the fourth harvest in year 90, yielding an estimated 16� 4% of the initial harvest volume during the fourth harvest. Increasing retention rates caused first-cut harvest volumes to decline but improved population recovery rates between harvests. Under both minimum diameter cutting limit scenarios, increasing retention rates led to more robust population recovery compared with the current 20% rate, and higher subsequent harvest yields relative to initial (first-cut) values. 5. Synthesis and applications. These results indicate that current harvest regulations in Brazil for mahogany and other high-value timber species with similar life histories will lead to commercial depletion after 2–3 cutting cycles. Increasing commercial-sized tree retention rates improved population recovery at the cost of reduced initial harvest volume yields. Sustainable harvests will require, in combination, a moderate increase in the retention rate, investment in

Following the Rules: Brazilian Logging Concessions under Imperfect Enforcement and Royalties

Debates about forest concessions in the Brazilian Amazon have focused on the government’s enforcement capacity. Using an optimization model largely parameterized with data from the Eastern Amazon, we investigate the effectiveness of renewability audits and performance bonds in inducing compliance with reduced-impact logging and harvest volume requirements. In weak enforcement environments, audits are unlikely to induce full compliance with harvest regulations, while performance bonds may be more effective. The use of royalty instruments such as the ad valorem and revenue-based royalties can generate revenues and, in the case of revenue-based instruments, modify harvest behavior, but only under limited circumstances. (JEL Q23, Q28)

Survival, growth and reproduction by big-leaf mahogany (Swietenia macrophylla) in open clearing vs. forested conditions in Brazil

Big-leaf mahogany (Swietenia macrophylla) trees are often retained in agricultural fields and pastures for seed and timber production after selective logging and forest clearing in the Brazilian Amazon. At a forest management site in southeast Pará, we censused trees growing scattered across a large open clearing after forest removal and in heavily disturbed forest after selective logging and canopy thinning for survival, stem diameter growth, fruit production, and date of dry season flowering initiation annually during 1997–2003. Trees in the open clearing died at faster rates, grew more slowly, produced fewer fruit, and initiated flowering earlier, on average, than trees in logged and thinned forest during this period. The principal cause of mortality and stem damage in both environments was dry season groundfires. Mahogany trees in logged and thinned forest at the study site grew faster than mahogany trees at a selectively logged but otherwise undisturbed closed-canopy forest site in this region during the same period. This was likely due to vine elimination by groundfires, increased crown exposure after canopy thinning, and soil nutrient inputs due to groundfires. Without effective regulation and control of anthropogenic fires, attempts to manage remnant mahogany trees for future timber yields or to restore commercially viable populations in this region may prove futile.

Fake legal logging in the Brazilian Amazon

Weak control and monitoring of logging permits put the most commercially valuable Amazonian tree species at risk in Brazil. Declining deforestation rates in the Brazilian Amazon are touted as a conservation success, but illegal logging is a problem of similar scale. Recent regulatory efforts have improved detection of some forms of illegal logging but are vulnerable to more subtle methods that mask the origin of illegal timber. We analyzed discrepancies between estimated timber volumes of the national forest inventory of Brazil and volumes of logging permits as an indicator of potential fraud in the timber industry in the eastern Amazon. We found a strong overestimation bias of high-value timber species volumes in logging permits. Field assessments confirmed fraud for the most valuable species and complementary strategies to generate a “surplus” of licensed timber that can be used to legalize the timber coming from illegal logging. We advocate for changes to the logging control system to prevent overexploitation of Amazonian timber species and the widespread forest degradation associated with illegal logging.

Enhancing Public Trust in Federal Forest Management

The connections between social and biophysical sciences are being forged in new ways as researchers and practitioners of natural resources seek to understand how lands can be managed for the benefit of human societies and the broader biotic community. Increasingly, we recognize that social and physical systems are tightly integrated, with human actions and decisions both shaping and shaped by the ecological systems in which they are embedded (e.g., Carpenter et al. 2009). In this context, a variety of social actors, including scientists, managers, policy makers, and the public, are collectively playing a larger role in decisions about environmental governance (e.g., collaboratives, chap. 9), drawing upon an accumulating body of knowledge describing the dynamics of complex socioecological systems. Learning-based approaches using adaptive-management experiments (chap. 8) represent one particular type of formal tool that can be appropriated to this process of adaptive environmental governance.