Monitoring ecosystem changes

Monitoring changes in the extent and state of ecosystems is necessary to quantify the magnitude of emissions released from the conversion and degradation of natural ecosystems, as well as the potential to mitigate climate change by conserving and restoring these ecosystems. Standardized, replicable, spatially explicit estimates of land cover change, combined with emission factors derived from estimates of biomass, are used to calculate both historical reference emission levels and emission reductions caused by mitigation actions. This is true for both national efforts and local pilot activities. For example, monitoring of deforestation in coastal Tanzania documented a reduction in the regional deforestation rate and associated GHG emissions, from 1.0%/year (0.63 Mt CO₂/year) in 1990–2000 to 0.4%/year (0.20 MtCO₂/year) in 2000–2007 .

Forest monitoring serves several purposes beyond regular reporting of emissions and their reductions. Data on past land cover change and associated models of potential future change can inform REDD+ prioritization and planning. The same study of deforestation in Tanzania showed that deforestation rates inside of protected areas were 0.2%/year from 1990 to 2000 and from 2000 to 2007, versus deforestation rates outside of protection of 1.3% from 1990 to 2000 and 0.6% from 2000 to 2007, suggesting, although not proving, that protected areas were the cause of the lower rates. Monitoring in near-real time can enable time-sensitive alerts to government agencies and project management for rapid management responses . Subscribed users to CI’s near-real time Fire Alert System use the daily fire alert information to control active fires, to study the influence of climate change on fire frequency and to support policy enforcement inside protected areas . For example, in 2011 a fire inside Indonesia’s Kerinci Seblat National Park was detected by satellite observation. Within 24 h an email alert from the Fire Alert System informed the park manager, who then dispatched rangers to investigate. The discovery of illegal clearing deep inside the park resulted in 81 arrests the same day.

Applying standardized forest inventory methods in a network of permanent field plots, as promoted by the Tropical Ecosystem Assessment and Monitoring Network, can be used to monitor changes in forest carbon stocks over time. Inventory methods can detect subtle yet important changes in biomass that may be occurring over large areas that have not necessarily undergone a conversion in use. Such monitoring improves understanding of the impacts of climate change and land use change on tree species composition, aboveground carbon stocks and productivity. For example, such monitoring contributed to the discovery that a 2005 drought turned the Amazon rainforest from a net carbon sink to a net carbon source (1.2–1.6 more PgC emitted compared with predrought conditions) .

Monitoring has also revealed nonforest ecosystems as important potential sources of climate change mitigation. Initial results from monitoring carbon in coastal ecosystems (i.e., seagrasses, salt marshes and mangroves) suggest that although these ecosystems cover only an estimated 33–115 million ha globally, the high soil carbon densities and high estimated rate of loss of these ecosystems of 0.4–3.0%/year are responsible for emissions of 0.15–1.02 Pg CO₂/year .

Data on forest change can be combined with data on biodiversity or ecosystem services to analyze the noncarbon benefits of REDD+ activities. By providing indicators of biodiversity trends and the status and preservation of carbon stocks over time, monitoring of carbon and biodiversity in Tropical Ecosystem Assessment and Monitoring field plots can be used to inform National Biodiversity Strategies and Action Plans and to measure progress toward the Aichi Biodiversity Targets under the Convention on Biological Diversity. Continual technological advances in mobile devices and online data sharing platforms can enable community-based data collection initiatives to achieve greater spatial coverage of ecosystems’ multiple benefits at increasingly fine spatial scales.

Synergies & tradeoffs among ecosystems’ multiple benefits

By conserving and restoring natural ecosystems for climate change mitigation, many other ecosystem services are provided as well. Tropical rainforests provide habitat for extraordinary biodiversity; they are home to 23 of Earth’s 35 biodiversity hotspots . Tropical forests and wetlands improve downstream water quality by reducing soil erosion, nutrient depletion and sedimentation . Mangrove ecosystems provide coastal protection from storms, sediment regulation, coastal water quality control, fisheries and fiber production . Furthermore, the conservation and restoration of natural ecosystems can help people adapt to climate change impacts across multiple human development sectors, including disaster risk reduction, food security, sustainable water management and livelihood diversification . However, in some cases there may be trade-offs between ecosystems’ carbon and noncarbon benefits. For instance, areas of highest carbon densities may not always spatially coincide with areas of highest biodiversity. And without appropriate planning, climate change mitigation activities could have a variety of unintended, negative consequences for biodiversity .

Understanding the synergies and tradeoffs between climate change mitigation and ecosystems’ other benefits can aid in designing policy instruments, selecting management techniques and geographically targeting actions. For example, joint consideration of the values provided by sites for biodiversity conservation, water provision and carbon storage can help identify a network of sites that provides the most desirable bundle of services . For a given budget or constraint on total management area, one selection of sites might provide slightly less carbon than another, but produce much higher biodiversity conservation or water value. For example, in an evaluation of alternative global networks of conservation sites, a shift in priorities from only carbon to multiple services reduced the optimal network’s carbon storage by just 7% while increasing biodiversity representation more than tenfold .

Synergies and tradeoffs may even exist between conservation and restoration activities. In some cases restoration can enhance the value of maintained ecosystems, for instance by enhancing connectivity through the creation of new habitat corridors . Conversely, in other cases funds spent on restoration efforts could be more cost-effectively used to prevent ecosystem loss. For example, restoring forests in community-managed areas of Madagascar costs an estimated net present US$962–3226/ha, while avoiding deforestation in the same areas costs an estimated $252–1069/ha .

Policies, incentives & practices for multiple benefits

Well-designed policies can enhance the provision of climate and nonclimate benefits. While most international REDD+ policies can be expected to provide some level of biodiversity co-benefits by reducing forest habitat loss, some policies can lead to even greater biodiversity benefits. Such policies include greater finance for REDD+, as well as broader participation among countries so that deforestation is not displaced across borders .

One commonly suggested international policy to increase the biodiversity benefits of REDD+ is to supplement carbon payments with biodiversity payments based on the biodiversity conservation value of countries’ or sites’ avoided deforestation. Paradoxically, spending money on a mixture of carbon payments and biodiversity payments has the potential to incentivize the provision of greater climate benefits than spending an equal amount of money on carbon payments alone . This unexpected result arises when diversifying payments across multiple services allows a funding agency to spend less on surplus payments to sites that would choose to avoid deforestation even with lower payments and to spend more on payments to sites where only combined carbon and biodiversity payments are sufficient to incentivize avoided deforestation.

Countries participating in REDD+ may choose to tailor incentives and benefit-sharing systems to promote multiple benefits. For example, Ecuador’s Socio Bosque is a national conservation agreement program through which the national government provides direct monetary payments to landowners and communities for each hectare of native forest or other ecosystem they agree to protect and monitor . Areas are prioritized for inclusion not only on the basis of deforestation threat and carbon storage, but also on water cycle regulation, biodiversity habitat and contribution to poverty alleviation. More than 126,000 beneficiaries have entered more than 1.1 million ha in the program. The program is being replicated in the department of Pando and the municipality of San Ignacio de Velasco, both in Bolivia.

The sustainability of REDD+ initiatives is likely to depend upon the extent to which these initiatives avoid harm and instead create benefits for local people and the environment. Methods for promoting better outcomes for local people and the environment include social impact assessments that are participatory and integrated into the design of REDD+ initiatives and systems to monitor noncarbon impacts and promote adaptive management. Third-party standards such as the Climate, Community and Biodiversity Standards and the REDD+ Social and Environmental Standards are intended to ensure that REDD+ initiatives not only deliver mitigation benefits, but also provide positive impacts on biodiversity and local communities . Documented social and environmental benefits can boost investors’ confidence in REDD+ initiatives, which can in turn increase funding available for mitigation activities.

Future perspective

Nature-based climate change mitigation is an emerging field. The last half-decade has seen a rapid proliferation of nature-based mitigation initiatives seeking to generate multiple benefits, ranging from government programs to site-level REDD+ projects. Rigorous monitoring and evaluation of these early initiatives can enable retrospective analyses of their effectiveness in achieving multiple benefits. Documenting the successes and failures of these efforts can provide a vital body of information for adaptive management and to inform the next generation of policy initiatives. For example, an initial synthesis of lessons learned from early REDD+ pilot projects found that success in delivering biodiversity and social benefits depended on effective on-the-ground partnerships, sustained financing, successful stakeholder engagement and government support, high-quality technical analyses of carbon benefits and other ecosystem services, and the extent to which the projects were specifically designed with multiple benefits in mind . In the 3 years since that initial synthesis, dozens of new initiatives have started, and there is a need to analyze and learn from their successes and failures.

This paper has highlighted selected examples of research on monitoring ecosystems, analyzing synergies and tradeoffs across ecosystem benefits, designing policies and practices, and evaluating initiatives conducted by CI. With the exception of Davies et al. and Donato et al., all works cited had lead authors or co-authors from CI. Continued research in these fields can help decision-makers conserve and restore ecosystems in ways that not only mitigate climate change but also promote multiple social and environmental benefits. Achieving multiple benefits can in turn increase the sustainability of and investment in nature-based mitigation.