Conservation Biology

Abstract:  Brazil's Amazon forest remained largely intact until the “modern” era of deforestation began with the inauguration of the Transamazon Highway in 1970. Amazonian deforestation rates have trended upward since 1991, with clearing proceeding at a variable but rapid pace. Although Amazonian forests are cut for various reasons, cattle ranching predominates. The large and medium‐sized ranches account for about 70% of clearing activity. Profit from beef cattle is only one of the income sources that make deforestation profitable. Forest degradation results from logging, ground fires (facilitated by logging), and the effects of fragmentation and edge formation. Degradation contributes to forest loss. The impacts of deforestation include loss of biodiversity, reduced water cycling (and rainfall), and contributions to global warming. Strategies to slow deforestation include repression through licensing procedures, monitoring, and fines. The severity of penalties for deforestation needs to be sufficient to deter illegal clearing but not so great as to be unenforceable. Policy reform is also needed to address root causes of deforestation, including the role of clearing in establishing land claims.

We revisited 68 plots of forest vegetation in the San Bernardino Mountains that had been quantitatively described in 1929‐1935, from the California Vegetation Type Map (VTM) Survey. By using the same sampling methods, we documented changes—over approximately 60 years and during a period of fire suppression management—in tree density by both species and size class. In general, we found increasing stand densities, a transformation from old‐growth age structure to young growth, and a compositional shift from Pinus ponderosa and P. jeffreyi to Abies concolor and Calocedrus decurrens. Density of trees of more than 12 cm diameter at breast height (dbh) increased by 79%, including three to ten‐fold increases in the youngest cohorts 12–66 cm dbh. The magnitude of change depended upon initial forest composition and local annual precipitation. Monotypic stands of P. jeffreyi or those initially dominated by Abies concolor showed the least change in species composition; the most xeric stands of P. jeffreyi showed the least gain in density; and mesic mixed P. ponderosa stands showed the most dramatic change in composition and density. We compared these data to records of past and present forests in the Sierra Nevada and found parallel trends, but magnified by the increased precipitation of the Sierra Nevada. We also compared VTM data from the San Bernardino Mountains to mixed conifer forests in the Sierra San Pedro Martir of Baja California. These Mexican sites and forests are ecologically similar to those in California, but they still experience unmanaged fire regimes. Californian forests of 60 years ago are remarkably similar to modern forests in the Sierra San Pedro Martir. Thus, we conclude that forest changes in the San Bernardino Mountains are primarily due to lengthening fire intervals. Forest changes as a result of fire suppression have important conservation consequences for bird species diversity in general and for Spotted Owl and Neotropical migrants in particular.

The Common Agricultural Policy (CAP) is the European Union's main instrument for agricultural planning, with a new reform approved for 2023–2027. The CAP intends to align with the European Green Deal (EGD), a set of policy initiatives underpinning sustainable development and climate neutrality in the European Union (EU), but several flaws cast doubts about the compatibility of the objectives of these 2 policies. We reviewed recent literature on the potential of CAP environmental objectives for integration with the EGD: protection of biodiversity, climate change mitigation and adaptation, and sustainable management of natural resources. The CAP lacks appropriate planning measures, furthering instead risks to biodiversity and ecosystem services driven by landscape and biotic homogenization. Funding allocation mechanisms are not tailored to mitigate agricultural emissions, decreasing the efficiency of climate mitigation actions. The legislation subsidies farmers making extensive use of synthetic inputs without adequately supporting organic production, hindering the transition toward sustainable practices. We recommend proper control mechanisms be introduced in CAP Strategic Plans from each member state to ensure the EU is set on a sustainable production and consumption path. These include proportional assignment of funds to each CAP objective, quantitative targets to set goals and evidence‐based interventions, and relevant indicators to facilitate effective monitoring of environmental performance. Both the CAP and the EGD should maintain ambitious environmental commitments in the face of crisis to avoid further degradation of the natural resources on which production systems stand.

Abstract:  There is growing recognition among conservation practitioners and scholars that good project management is integrally linked to well‐designed monitoring and evaluation systems. Most conservation organizations have attempted to develop and implement monitoring and evaluation systems, often with mixed results. One problem seems to be that organizations are trying to build their systems from scratch, overlooking lessons learned from the many efforts to develop useful and practical monitoring and evaluation approaches. Thus, we undertook a review of monitoring and evaluation approaches in conservation and other fields including international development, public health, family planning, education, social services, and business. Here, we present our results for the field of conservation. We categorized the considerable variety of monitoring and evaluation approaches into four broad purposes: basic research; accounting and certification; status assessment; and effectiveness measurement. We focus here on status assessment and effectiveness measurement. Specific lessons that emerged follow: different monitoring and evaluation needs require different approaches; conceptual similarities are widespread among prevailing approaches; inconsistent language impedes communication; confusion among monitoring and evaluation components hinders practitioner ability to choose the appropriate component; and monitoring only quantitative biological variables is insufficient. We suggest that the conservation community continue support of collaborative initiatives to improve monitoring and evaluation, establish clear definitions of commonly used terms, clarify monitoring and evaluation system components, apply available approaches appropriately, and include qualitative and social variables in monitoring efforts.

Abstract:  Community‐based conservation (CBC) is based on the idea that if conservation and development could be simultaneously achieved, then the interests of both could be served. It has been controversial because community development objectives are not necessarily consistent with conservation objectives in a given case. I examined CBC from two angles. First, CBC can be seen in the context of paradigm shifts in ecology and applied ecology. I identified three conceptual shifts—toward a systems view, toward the inclusion of humans in the ecosystem, and toward participatory approaches to ecosystem management—that are interrelated and pertain to an understanding of ecosystems as complex adaptive systems in which humans are an integral part. Second, I investigated the feasibility of CBC, as informed by a number of emerging interdisciplinary fields that have been pursuing various aspects of coupled systems of humans and nature. These fields—common property, traditional ecological knowledge, environmental ethics, political ecology, and environmental history—provide insights for CBC. They may contribute to the development of an interdisciplinary conservation science with a more sophisticated understanding of social‐ecological interactions. The lessons from these fields include the importance of cross‐scale conservation, adaptive comanagement, the question of incentives and multiple stakeholders, the use of traditional ecological knowledge, and development of a cross‐cultural conservation ethic.

Abstract:Conservation of rare plant populations is an important dimension of the preservation of biodiversity. Yet the database underlying both the theoretical understanding and management of rare—in contrast to common—plant species is scattered, unfocused, and conceptually weak. Our review of studies comparing attributes of rare vascular plants with those of closely related, more common relatives found fewer studies than expected (n= 38) and no consistency in the attributes measured, which precluded further assessment of pattern. Only 10% of 71 response variables compared were reported in more than four studies, and most of the traits ( 79%) were compared in only one or two studies. Improvement of comparisons of rare and common species requires standardization of attributes measured among studies. Although experiments evaluating hypothesized limiting factors are desirable, at a minimum all studies should include population densities and life table schedules. Demographic parameters provide detailed data, required for scientific management of specific rare plants, and extensive data, required for meta‐analyses and detection of general patterns in rarity.

Abstract:Researchers concerned with sustainable management of forests in the tropics have argued that the road to improved stewardship of forest resources is the transfer of responsibility to the local communities who get their livelihoods from them. On the other hand, conservationists have declared that the only way to stem the tide of deforestation is to place as many tracts as possible under strict protection. In this context, Mexico presents a national laboratory for studying the social and ecological benefits of delivering forests to local people. As a little‐noticed result of the Mexican Revolution in the second decade of the twentieth century, well over half of the forests of Mexico were placed in community‐held lands. In historic struggles that passed through several phases, most of these communities have now gained substantial control over the use of their forests. Because of the substantial degree of social capital in rural forms of organization in Mexico, this control of forest resources has led to an estimated 290–479 community forest enterprises ( CFEs ), through which communities are producing timber on their own lands. New studies are beginning to suggest that important gains in both social and economic justice, good forest management, and biodiversity protection are resulting from the actions of these CFEs. As more forests globally are being devolved to local communities, it is important to carry out more research on the Mexican model of community forest management for timber production.

The world’s tropical forests are being cleared rapidly, and ecologists claim this is causing a massive loss of species. This claim has its critics. Can we predict extinctions from the extent of deforestation? We mapped the percentage of deforestation on the islands of the Philippines and Indonesia and counted the number of bird species found only on these islands. We then used the species‐area relationship to calculate the number of species predicted to become globally extinct following deforestation on these islands. Next, we counted the numbers of insular southeast Asian endemic bird species considered threatened—i.e., those having “a high probability of extinction in the wild in the medium‐term future”—in the latest summary Red Data Book. The numbers of extinctions predicted from deforestation and the numbers of species actually threatened are strikingly similar. This suggests we can estimate the size of the extinction crisis in once‐forested regions from the extent of deforestation. The numbers of extinctions will be large. Without rapid and effective conservation, many of the species endemic to insular southeast Asia will soon be lost.