Peer-reviewed publications

Over the last 25 years, the global area of certified forests has grown rapidly and voluntary forest certification has become recognized as an effective tool to engage international markets in improving sustainability within forest management units. However, the bulk of this growth has occurred in North America, Northern Europe, Australia, and New Zealand, with relatively limited uptake in the tropics. Since its creation, forest certification has been largely understood as a "market-based" mechanism, in contrast to government-led policies and regulations. Through the experience of the Responsible Asia Forestry and Trade (RAFT) partnership in the Asia Pacific region, we find that the framing of forest certification as voluntary and market-based, and as a mechanism to overcome governance failure, has created an artificial dichotomy. In this dichotomy, voluntary certification and regulatory measures to promote sustainable forest management are conceived of and pursued largely independently. We argue that it is more constructive to view them as complementary approaches that share a common goal of increasing sustainability across the forestry sector. In practice, forest certification interacts with conventional governance institutions and mechanisms. Understanding these interactions and their implications, as well as additional possibilities for interaction, will help in realizing the full potential of forest certification.

The expansion of oil palm plantations in Papua province, Indonesia, involves the conversion of forests, among other land types in the landscapes, which are a source of clan members' livelihoods. The way in which this expansion occurs makes it necessary to understand the factors associated with why companies look for frontier lands and what externalities are generated during both the land acquisition and plantation development periods. Using a spatial analysis of the concession areas, along with data from household surveys of each clan from the Auyu, Mandobo, and Marind tribes who release land to companies, we find that investors are motivated to profit from timber harvested from the clearing of lands for plantations, activity that is facilitated by the local government. Land acquisition and plantation development have resulted in externalities to indigenous landowners in the form of time and money lost in a series of meetings and consultations involving clan members and traditional elders. Other externalities include the reduced welfare of people due to loss of livelihoods, and impacts on food security.

Expanding human populations, combined with an increasingly variable climate, present challenges to the conservation of wide-ranging wildlife species, particularly for populations that persist in human-dominated landscapes. Although the movements and space use of many equid species have been well studied, comparable research of the Hartmann's mountain zebra (HMZ) Equus zebra hartmannae, which primarily inhabits communal and commercial farming areas of Namibia, has been scarce and may limit conservation effectiveness. Here, we investigated the environmental and anthropogenic factors influencing HMZ movements and resource use across a large area of their range in northwestern Namibia. We deployed 6 GPS collars on HMZ during 2011 to 2013 and used integrated step selection functions to quantify HMZ movements and space use. HMZ movements averaged ˜5 km d-1, and mean seasonal home range sizes were 681 and 256 km2 in the wet and dry season, respectively. HMZ selected for areas with high normalized difference vegetation index values (used as a proxy for primary production), particularly during the dry season, while avoiding areas further from water and closer to human settlements, although the effect was less apparent during the rainy season. Movement rates increased when HMZ crossed roads and were closer to roadways, but rates were not impacted by proximity to human activities. These results provide insights toward mitigating human-HMZ conflict. We highlight the difficulty a changing and less predictable climate creates for grazing species living in arid regions, as they must expend more energy and navigate dangers of a growing human footprint to seek out valuable but ephemeral forage.

Stabilizing Earth's climate and limiting temperature increase to well below 2°C per the Paris Agreement requires a dramatic uptick in the rate of progress on reducing greenhouse gas (GHG) emissions. Natural climate solutions (NCS) can be a substantial contributor, while also providing valuable cobenefits for people and ecosystems. Although analyses of NCS have some differences in the GHG fluxes they consider, all include emissions sources (such as deforestation, land-use change, and agricultural practices), emissions sinks (such as reforestation and restoring degraded lands), and non–carbon dioxide (CO2) agricultural emissions (such as methane from livestock). Some of us have contributed to among the most optimistic assessments of the potential of NCS (1), whereas others have been more pessimistic (2, 3). But one thing on which we agree, and which technical literature generally acknowledges, is that the benefits of NCS do not decrease the imperative for mitigation from the energy and industrial sectors (2, 4, 5). Yet this point sometimes gets lost in public-facing conversations [for example, are forests "our best weapon for fighting carbon emissions" or, more realistically, just one "piece of the puzzle"? (6)]. Strategies for incorporating NCS with energy and industrial mitigation in the climate portfolio should not be "either/or" but "yes, and."

In 2015, the UN adopted 17 Sustainable Development Goals (SDGs), aiming to "protect the planet from degradation...so that it can support the needs of the present and future generations". Through the SDGs, the UN recognises that conservation directly supports human health and wellbeing by providing goods like water and fibre, and global public goods like habitat for species and mitigation of climate change. Although trade-offs can indeed arise between conservation and economic development, the Rockefeller Foundation–Lancet Commission on planetary health states unequivocally that "the environment has been the foundation of human flourishing", suggesting that if environmental degradation persists then ongoing improvements in human health are likely to be reversed.

Forests in southwestern Amazonia are increasingly being converted for agriculture, mining, and infrastructure development; subjected to low-intensity selective logging of high value timber species; and designated as conservation areas and indigenous reserves. To understand the impacts of forestry in this region, we evaluated carbon emissions from felling, skidding, and hauling in five FSC-certified concessions where workers were trained in reduced-impact logging (RIL) and in four non-certified concessions where workers were not trained in RIL in Madre de Dios, Peru. Emissions estimates did not differ by certification status, so we established a single baseline for selective logging emissions. Total carbon emissions from selective logging were low per hectare (4.9-11.6Mg ha-1) due to low logging intensities (2.9-8.1 m3 ha-1). Despite the unique architecture of trees in the southwestern Amazon (short stems and large crowns), emissions per volume and per ton carbon in the extracted timber were also relatively low (1.55 Mg m-3 and 4.04 Mg Mg-1, respectively). Only emissions per area scaled with logging intensity. Emissions were dominated by the felled tree itself (in extracted logs and residuals), whereas hauling infrastructure (roads and log landings) contributed comparatively little.

Selective logging causes at least half of the emissions from tropical forest degradation. Reduced-impact logging for climate (RIL-C) is proposed as a way to maintain timber production while minimizing forest damage. Here we synthesize data from 61 coordinated field-based surveys of logging impacts in seven countries across the tropics. We estimate that tropical selective logging emitted 834 Tg CO2 in 2015, 6% of total tropical greenhouse gas emissions. Felling, hauling, and skidding caused 59%, 31%, and 10% of these emissions, respectively. We suggest that RIL-C incentive programs consider a feasible target carbon impact factor of 2.3 Mg emitted per Mg of timber extracted. Operational modifications are needed to achieve this target, such as reduced wood waste, narrower haul roads, and lower impact skidding equipment. Full implementation would reduce logging emissions by 44% (366 Tg CO2 year-1) and deliver 4% of the nationally determined contributions to the Paris Climate Agreement from tropical countries, while maintaining timber supplies.

Conversion of temperate grasslands in the North American Great Plains has long been identified as a threat to native species and systems. Avoiding conversion, particularly to agricultural cover, has been modeled to show benefits for preserving species diversity and connectivity and maintaining ecosystem services provided by grasslands such as avoiding nutrient and sediment runoff. To identify areas of likely conversion, we employed a probabilistic ecoregion-wide model using soil, topography, and climate variables to simulate future conversion. Our results indicated that roughly 60% of the ecoregion is at moderate or higher risk of conversion or has previously been converted. These data can be used to direct grassland conservation efforts and as a metric to assess suitability of future crop expansion. Also, with added information on government subsidies, clean energy mandates, conservation incentives, and other economic data, our model can be used to assess the benefits and disadvantages of such programs and policies.

Calls for coral reef restoration are increasing amidst continued declines, yet we know little about long-term outcomes and conditions that lead to successful coral recovery. Here, we report on one of the longest monitoring studies following 16 years of large-scale, "low-tech" experimental reef rehabilitation on rubble fields created by chronic blast fishing in Komodo National Park, Indonesia. After blast fishing had stopped, in the absence of rehabilitation, hard coral cover in rubble fields remained about 3% from 1999 to 2016, but on rehabilitation treatments, cover increased from 0% in 2002 to 44.5% (± 21.9% SD) in 2016. Coral cover varied among sites and treatments (ranging from <5 to &rt80% in 2016) in patterns that may reflect current strength and turbidity. Our results demonstrate that low-tech substrate stabilization can facilitate natural coral recruitment and growth. We conclude that relatively low-cost methods can deliver sustained rehabilitation of hard coral cover and that long-term monitoring should be incorporated more widely in restoration activities to inform return on investment.

The signing of the Paris climate agreement and sustainable development goals demonstrated an international commitment to halting climate change, increasing energy access, and maintaining biodiversity. Successful implementation requires rapidly expanding renewable energy development, which has a large land footprint and can conflict with maintaining natural lands. To quantify the potential to mediate this land conflict, we converted emission reduction commitments submitted as part of the Paris agreement into actionable energy targets, and assessed whether they can be met by developing renewables on converted lands and waters of lower biodiversity and carbon value. The world has 19 times the required energy targets on converted lands, and most countries, including the top ten emitters, can meet the Paris agreement goals. Furthermore, regions (e.g. Africa) that will experience substantial population growth and that currently have limited energy infrastructure can meet their Paris agreement and future energy targets by developing renewable energy on already converted lands. Guiding renewable energy development to converted lands presents opportunities for sustainable development, but also requires incentives and proactive planning to ensure expansion does not exacerbate other environmental challenges.