Woods Hole Research Center

2009

Bergen, K.M., S.J. Goetz, R.O. Dubayah, G.M. Henebry, C.T. Hunsaker, M.L. Imhoff, R.F. Nelson, G.G. Parker, and V.C. Radeloff. 2009. Remote sensing of vegetation 3-D structure for biodiversity and habitat: Review and implications for lidar and radar spaceborne missions.  Journal of Geophysical Research 114 G00E06, doi:10.1029/2008JG000883.

Biodiversity and habitat face increasing pressures due to human and natural influences that alter vegetation structure. Because of the inherent difficulty of measuring forested vegetation three-dimensional (3-D) structure on the ground, this important component of biodiversity and habitat has been, until recently, largely restricted to local measurements, or at larger scales to generalizations. New lidar and radar remote sensing instruments for spaceborne missions will provide the capability to fill this gap. This paper reviews the state of the art for incorporating information on vegetation 3-D structure into biodiversity and habitat science and management approaches, with emphasis on use of lidar and radar data. The possibility to derive vegetation 3-D measurements from spaceborne active sensors and to integrate them into science and management comes at a critical juncture for global biodiversity conservation and opens new possibilities for advanced scientific analysis of habitat and biodiversity.

Busch, J., B. Strassburg, A. Cattaneo, R. Lubowski, A. Bruner, R. Rice, A. Creed, R. Ashton, and F. Boltz. 2009. Comparing climate and cost impacts of reference levels for reducing emissions from deforestation. Environmental Research Letters 4:044006. doi:10.1088/1748-9326/4/4/044006

The climate benefit and economic cost of an international mechanism for reducing emissions from deforestation and degradation (REDD) will depend on the design of reference levels for crediting emission reductions. We compare the impacts of six proposed reference level designs on emission reduction levels and on cost per emission reduction using a stylized partial equilibrium model (the open source impacts of REDD incentives spreadsheet; OSIRIS). Our results show that a REDD mechanism can provide cost-efficient climate change mitigation benefits under a broad range of reference level designs. We find that the most effective reference level designs balance incentives to reduce historically high deforestation emissions with incentives to maintain historically low deforestation emissions.

Canadell, J.G., M.R. Raupach, and R.A. Houghton. 2009. Anthropogenic CO2 emissions in Africa. Biogeosciences 6:463-468.

This paper reports CO2 emissions from the African continent as a result of fossil fuel combustion and land use change. Over the period 2000-2005, the combustion of fossil fuels released 260 TgC y-1 and land-use change released 240 TgC y-1, for a total of 500 TgC y-1. Countries with higher than average emissions from fossil fuels generally had lower than average emissions from land-use change, and vice versa. The African share of global emissions from land-use change was 17%; for fossil fuels it was 3.7% (285 TgC in 2005). The growth rate in African fossil fuel emissions was 3.2% y-1, very close to the global average; and the average amount of carbon emitted per 1US$ of Gross Domestic Product (GDP) was also close to the world average. Per capita fossil fuel emissions in Africa are among the lowest in the world, at 0.32 tC y-1 compared to the global average of 1.2 tC y-1.

Cattaneo, A. (2009) “Incentives to reduce emissions from deforestation: a stock-flow approach with target reductions”, in V. Bosetti and R. Lubowski., editors. Deforestation and Climate Change: Reducing Carbon Emissions from Deforestation and Forest Degradation.

This paper introduces a mechanism to distribute REDD incentives that is tailored to broaden participation in REDD  and at the same time maximize individual countries’ contribution to reducing emissions from deforestation.  In a program where participation is voluntary, the design of the incentives has to take into consideration both the environmental target to be reached and how to distribute REDD ‘profits’ to encourage broad participation. The incentives provided by the stock-flow approach are confirmed by simulation results indicating that the version of the stock-flow mechanism incorporating targets is, under the modeled conditions, the most environmentally effective leading to a potential 73% reduction in emissions from deforestation. The stock-flow with targets is also among the more economically efficient (92%) and more equitable relative to distributing REDD revenues proportionately to opportunity costs (Gini coefficient of 0.25), and stimulates the broadest participation with all 84 modeled countries having positive returns from participation in REDD.

Clark, C.J., J.R. Poulsen, R. Malonga, and P.W. Elkan, Jr. 2009. Logging Concessions Can Extend the Conservation Estate for Central African Tropical Forests. Conservation Biology 23(5):1281–1293. doi:10.1111/j.1523-1739.2009.01243.x

The management of tropical forest in timber concessions is one solution to prevent biodiversity loss. The effectiveness of this strategy will likely depend on species-specific, population-level responses to logging. We surveyed logging concessions in the Republic of Congo to examine the impact of logging on large mammal populations, including endangered species such as apes, elephant, and bongo. Managed production forest retained similar abundances of large mammals as unlogged forest and an adjacent protected area. Species responded nonlinearly to logging history, with abundances changing over 30 years as forest recovered from logging. For many species, abundance was related to the distance to unlogged forest, suggesting that intact forest acts as source habitat. Logged forest can extend the conservation estate for many threatened species if managed for hunting; but concessions should also be large, contain patches of unlogged forests, and include forest with varying logging histories to maximize their conservation potential.

Coe, M.T., M.H. Costa, and B.S. Soares-Filho. 2009. The Influence of Historical and Potential Future Deforestation on the Stream Flow of the Amazon River -- Land Surface Processes and Atmospheric Feedbacks. Journal of Hydrology doi:10.1016/j.jhydrol.2009.02.043

Results from two sets of numerical simulations illustrate the influence of historical and potential future deforestation on local evapotranspiration and discharge of the Amazon River system with and without atmospheric feedbacks and clarify. In the absence of a continental scale precipitation change, large-scale deforestation can have a significant impact on large river systems and appears to have already done so in the Tocantins and Araguaia Rivers, where discharge has increased 25% with little change in precipitation. However, with extensive deforestation (e.g. >30% of the Amazon basin) atmospheric feedbacks cause significantly decreases in precipitation. Changes caused by atmospheric feedbacks are not limited to those basins where deforestation has occurred but are spread unevenly throughout the entire Amazon by atmospheric circulation. As a result, changes to discharge and aquatic environments with future deforestation of the Amazon will likely be significant and a complex function of how much vegetation has been removed from that particular watershed and how much has been removed from the entire Amazon Basin.

Davidson, E.A. 2009. The contribution of manure and fertilizer nitrogen to atmospheric nitrous oxide since 1860. Nature Geoscience September doi:10.1038/ngeo608

Atmospheric nitrous oxide concentrations have been increasing since the industrial revolution and currently account for 6% of total anthropogenic radiative forcing.  Microbial production in soils is the dominant nitrous oxide source, which has increased with increasing use of nitrogen fertilisers.  However, fertiliser use alone cannot account for the historical trends of atmospheric concentrations of nitrous oxide.  Here, I analyze atmospheric concentrations, industrial sources of nitrous oxide, and fertiliser and manure production since 1860.  Prior to 1960, agricultural expansion, including livestock production, may have caused globally significant mining of soil nitrogen, fuelling a steady increase in atmospheric nitrous oxide.  Post 1960, the rate of the increase rose, due to accelerating use of synthetic nitrogen fertilizers.  Using a regression model, I show that 2% of manure nitrogen and 2.5% of fertilizer nitrogen was converted to nitrous oxide between 1860 and 2005; these percentage contributions explain the entire pattern of increasing nitrous oxide concentrations over this period.  As animal protein consumption in human diets increases globally, management of manure will be just as an important as improved fertilizer use efficiency to reduce anthropogenic nitrous oxide sources.

Goetz, S.J., and P.S.A. Beck. 2009. Recent changes in boreal and Arctic vegetation and their feedbacks to the climate system. iLEAPS Newsletter 8:16-19.

High northern latitudes have experienced the fastest rates of climate warming in the past decades. This review gives an overview of the changes in terrestrial high latitude vegetation, i.e. the tundra and taiga biomes, observed in response to the changes in climate, and discusses how they feed back to the climate system, potentially exacerbating (through a positive feedback) or attenuating future climate change (through a negative feedback). The role of changes in vegetation productivity and shifts in functional types of vegetation are highlighted, in particular with respect to their effects on the carbon and energy budgets. In forested ecosystems ongoing changes in the fire regime, which are caused by climate change, produce an additional set of climate feedbacks. Fire not only causes emissions from combustion but alters the landscape and ecosystem-climate effects for decades following the fire event through regrowth of vegetation. The nature of the responses and feedbacks of high latitude vegetation to climate change are well-understood, but the magnitude of the different feedbacks and the trade-offs between them are currently poorly constrained and need further research.

Goetz, S.J., A. Baccini, N.T. Laporte, T. Johns, W. Walker, J. Kellndorfer, R.A. Houghton, and M. Sun. 2009. Mapping and monitoring carbon stocks with satellite observations: a comparison of methods. Carbon Balance and Management 4:2.

Mapping and monitoring carbon stocks in forested regions of the world, particularly the tropics, has attracted a great deal of attention in recent years as deforestation and forest degradation account for a significant portion of anthropogenic carbon emissions, and are now included in climate change negotiations. We review the potential for satellites to measure carbon stocks, specifically aboveground biomass (AGB), and provide an overview of a range of approaches that have been developed and used to map AGB across a diverse set of conditions and geographic areas.  We provide a summary of the types of remote sensing measurements relevant to mapping AGB, and assess the relative merits and limitations of each.  We conclude that while satellite remote sensing has often been discounted as inadequate for the task, attempts to map AGB without satellite imagery are insufficient.  Moreover, remote sensing provides improved maps of AGB relative to more traditional approaches.

Houghton, R.A., M. Gloor, J. Lloyd, and C. Potter. 2009. The regional carbon budget. In Amazonia and Global Change, Geophysical Monograph Series 186, ed. M. Keller, M. Bustamante, J. Gash, and P.S. Dias, 409-428. American Geophysical Union, Washington, DC.

A number of approaches have been used to infer whether Amazonia is a net source or sink for atmospheric carbon. Top-down approaches based on inverse calculations with CO2 concentrations and atmospheric transport models are problematic because of a paucity of air samples. Direct measurements of CO2 flux with the eddy covariance technique indicate forests to be both sources and sinks of carbon, depending in part on when the last disturbance occurred. These flux measurements are extrapolated through time and space with ecosystem models, but many models fail to reproduce even the correct sign of carbon balance observed seasonally in some forests. Models based on land-use change and fire, including subsequent forest recovery, consistently calculate net carbon emissions, but increases in tree biomass measured in intact forest plots seem to offset the net source from disturbance. Taken together, these approaches suggest that Amazonia has been, on average, nearly neutral with respect to carbon over the last decade, albeit a small net source during El Niño events.

Nepstad, D.C., Soares, B.S., Merry, F.D., Lima, A., Moutinho, P., Carter, J., Bowman, M.S., Cattaneo, Rodrigues, H., Schwartzman, S., McGrath, D.G., Stickler, C.M., Lubowski, R., Piris-Cabezas, P., Rivero, S., Alencar, A., Almeida, O., Stella, O. 2009. The end of deforestation in the Brazilian Amazon. Science 326 (5958): 1350-1351.

Brazil has two major opportunities to end the clearing of its Amazon forest and to reduce global greenhouse gas emissions substantially. The first is its formal announcement within United Nations climate treaty negotiations in 2008 of an Amazon deforestation reduction target, which prompted Norway to commit $1 billion if it sustains progress toward this target. The second is a widespread marketplace transition within the beef and soy industries, the main drivers of deforestation, to exclude Amazon deforesters from their supply chains. According to our analysis, these recent developments finally make feasible the end of deforestation in the Brazilian Amazon, which could result in a 2 to 5% reduction in global carbon emissions. The $7 to $18 billion beyond Brazil's current budget outlays that may be needed to stop the clearing (a range intermediate to previous cost estimates) could be provided by the REDD (Reducing Emissions from Deforestation and Forest Degradation) mechanism for compensating deforestation reduction that is under negotiation within the UN climate treaty, or by payments for tropical forest carbon credits under a U.S. cap-and-trade system.

Poulsen, J.R., C.J. Clark, G. Mavah, and P.W. Elkan. 2009.  Bushmeat Supply and Consumption in a Tropical Logging Concession in Northern Congo. Conservation Biology 23(6):1597–1608.

Unsustainable hunting of wildlife for food empties tropical forests of many species critical to forest maintenance and livelihoods of forest people. Extractive industries, including logging, can accelerate exploitation of wildlife by opening forests to hunters and creating markets for bushmeat. We monitored human demographics, bushmeat supply in markets, and household bushmeat consumption in five logging towns in the Republic of Congo. Over 6 years we recorded 29,570 animals in town markets and collected 48,920 household meal records. Development of industrial logging operations led to a 69% increase in the population of logging towns and a 64% increase in bushmeat supply. Immigrants hunted 72% of all bushmeat, with the short-term benefits of hunting accrue disproportionately to “outsiders” rather than indigenous peoples. The greatest threat of logging to biodiversity may be the permanent urbanization of frontier forests, indicating that saw mills and the towns that develop around them should be kept out of forests.

Stickler, C.M., D.C. Nepstad, M.T. Coe, D.G. McGrath, H.O. Rodrigues, W.S. Walker, B.S. Soares-Filho, and E.A. Davidson. 2009. The potential ecological costs and cobenefits of REDD: a critical review and case study from the Amazon region. Global Change Biology 15:2803–2824.

We review the potential for REDD to provoke ecological damages and promote ecological co-benefits. Potential ecological costs include the accelerated loss of low-biomass, high-conservation-value ecosystems, and substitution of low-biomass vegetation by monoculture tree plantations. Substantial ecological co-benefits should be conferred under most circumstances, including the maintenance or restoration of watershed functions, local and regional climate regimes, soils and biogeochemical processes, water quality and aquatic habitat, and terrestrial habitat. Analysis of possible REDD program interventions in a large-scale Amazon landscape indicates that even modest flows of forest carbon funding can provide substantial co-benefits for aquatic ecosystems, but that the functional integrity of the landscape’s myriad small watersheds would be best protected under a more even spatial distribution of forests. Because of its focus on an ecosystem service with global benefits, REDD could access a large pool of stakeholders willing to pay to maintain carbon in forests, thereby providing a potential cascade of ecosystem services to local stakeholders who would otherwise be unable to afford them.