Earth's Forests Research Articles

Implication of the new VCS jurisdictional and nested REDD methodology on baselines of existing avoided deforestation projects

A changing climate is poised to inflict massive-scale damage through extreme weather events. Preserving Earth's forests stands out as a critical resource in our battle to mitigate climate change. One pivotal approach for this endeavour is the Reduction of Emissions from Deforestation and Forest Degradation (REDD), a climate change mitigation solution currently being enacted through locally-based projects certified by the Verified Carbon Standard (VCS) Association. Nevertheless, these REDD projects have recently faced severe scrutiny for potentially overemphasizing their effectiveness. To address these concerns, the VCS has put forth a new jurisdictional and nested REDD methodology. This study, therefore, aims to assess the impact of the new REDD methodology on the baseline measurements of existing REDD projects within the VCS registry. For this assessment, we selected four REDD projects, each spanning across four continents and encompassing two major forest types. An in-depth analysis of these four projects reveals a noteworthy trend: under the new methodology, three of them are projected to experience a substantial reduction in the number of issued credits compared to the previous methodologies. Consequently, it appears that the new REDD methodology holds promise in generating higher-quality credits by reducing the potential for an inflated baseline.

Weighing forests from space

Abstract Shaun Quegan discusses the upcoming ESA BIOMASS mission, charged with monitoring the health of Earth's forests.

A climate risk analysis of Earth's forests in the 21st century.

Earth's forests harbor extensive biodiversity and are currently a major carbon sink. Forest conservation and restoration can help mitigate climate change; however, climate change could fundamentally imperil forests in many regions and undermine their ability to provide such mitigation. The extent of climate risks facing forests has not been synthesized globally nor have different approaches to quantifying forest climate risks been systematically compared. We combine outputs from multiple mechanistic and empirical approaches to modeling carbon, biodiversity, and disturbance risks to conduct a synthetic climate risk analysis for Earth's forests in the 21st century. Despite large uncertainty in most regions we find that some forests are consistently at higher risk, including southern boreal forests and those in western North America and parts of the Amazon.

Facilitating Reforestation Through the Plant Microbiome: Perspectives from the Phyllosphere.

Tree planting and natural regeneration contribute to the ongoing effort to restore Earth's forests. Our review addresses how the plant microbiome can enhance the survival of planted and naturally regenerating seedlings and serve in long-term forest carbon capture and the conservation of biodiversity. We focus on fungal leaf endophytes, ubiquitous defensive symbionts that protect against pathogens. We first show that fungal and oomycetous pathogen richness varies greatly for tree species native to the United States (n = 0-876 known pathogens per US tree species), with nearly half of tree species either without pathogens in these major groups or with unknown pathogens. Endophytes are insurance against the poorly known and changing threat of tree pathogens. Next, we review studies of plant phyllosphere feedback, but knowledge gaps prevent us from evaluating whether adding conspecific leaf litter to planted seedlings promotes defensive symbiosis, analogous to adding soil to promote positive feedback. Finally, we discuss research priorities for integrating the plant microbiome into efforts to expand Earth's forests.

A CNN-based approach for the estimation of canopy heights and wood volume from GEDI waveforms

Full waveform (FW) LiDAR systems have proven their effectiveness to map forest biophysical variables in the last two decades, owing to their ability of measuring, with high accuracy, forest vertical structures. The Global Ecosystem Dynamics Investigation (GEDI) system on board the International Space Station (ISS) is the latest FW spaceborne LiDAR instrument for the continuous observation of Earth's forests. FW systems rely on very sophisticated pre-processing steps to generate a priori metrics in order to leverage their capabilities for the accurate estimation of the aforementioned forest characteristics. The ever-expanding volume of acquired GEDI data, which to date comprises more than 25 billion acquired unfiltered shots, and along with the pre-processed data, amounting to more than 90 TB of data, raises new challenges in terms of adapted preprocessing methods for the suitable exploitation of such a huge and complex amount of LiDAR data. To overcome the issues related to the generation of relevant metrics from GEDI data, we propose a new metric-free approach to estimate canopy dominant heights (Hdom) and wood volume (V) of Eucalyptus plantations over five different regions in Brazil. To avoid metric computation, we leverage deep learning techniques and, more in detail, convolutional neural networks with the aim to analyze the GEDI Level 1B geolocated waveforms. Performance comparisons were conducted between four convolutional neural network (CNN) variants using GEDI waveform data (either untouched, or subsetted) and a metric based Random Forest regressor (RF). Additionally, we tested if our framework can improve the generalization of the models to different distant regions. First, the models were trained using data from all the study regions. Cross validated results showed that the CNN based models compared well against their RF counterpart for both Hdom and V. The RMSE on the estimation of Hdom from the CNN based models varied between 1.54 and 1.94m with a coefficient of determination (R2) between 0.86 and 0.91, while the RF model produced an accuracy on Hdom estimates of 1.45m (R2 = 0.92). For V, CNN based estimations ranged from 27.76 to 33.33m3.ha−1 (R2 between 0.82 and 0.88), while for RF, the RMSE was 27.61m3.ha−1 (R2 = 0.88). Next, model generalization was assessed by means of a spatial transfer experiment. For Hdom, both the CNN and RF approaches showed similar performances to a global model, however, the CNN based approach showed higher variability on the estimation accuracy, and the variability was related to the forest structure between the trained and tested data (similar tree heights yield better accuracies). For the estimation of V, considering both approaches, the accuracy was dependent on the allometric relationship between Hdom and V in the training and testing regions while lower accuracies on V were obtained when the testing and training regions exhibited a different allometric relationship.

Biomass estimation from simulated GEDI, ICESat-2 and NISAR across environmental gradients in Sonoma County, California

Estimates of the magnitude and distribution of aboveground carbon in Earth's forests remain uncertain, yet knowledge of forest carbon content at a global scale is critical for forest management in support of climate mitigation. In light of this knowledge gap, several upcoming spaceborne missions aim to map forest aboveground biomass, and many new biomass products are expected from these datasets. As these new missions host different technologies, each with relative strengths and weaknesses for biomass retrieval, as well as different spatial resolutions, consistently comparing or combining biomass estimates from these new datasets will be challenging. This paper presents a demonstration of an inter-comparison of biomass estimates from simulations of three NASA missions (GEDI, ICESat-2 and NISAR) over Sonoma county in California, USA. We use a high resolution, locally calibrated airborne lidar map as our reference dataset, and emphasize the importance of considering uncertainties in both reference maps and spaceborne estimates when conducting biomass product validation. GEDI and ICESat-2 were simulated from airborne lidar point clouds, while UAVSAR's L-band backscatter was used as a proxy for NISAR. To estimate biomass for the lidar missions we used GEDI's footprint-level biomass algorithms, and also adapted these for application to ICESat-2. For UAVSAR, we developed a locally trained biomass model, calibrated against the ALS reference map. Each mission simulation was evaluated in comparison to the local reference map at its native product resolution (25 m, 100 m transect, and 1 ha) yielding RMSEs of 57%, 75%, and 89% for GEDI, NISAR, and ICESat-2 respectively. RMSE values increased for GEDI's power beam during simulated daytime conditions (64%), coverage beam during nighttime conditions (72%), and coverage beam daytime conditions (87%). We also test the application of GEDI's biomass modeling framework for estimation of biomass from ICESat-2, and find that ICESat-2 yields reasonable biomass estimates, particularly in relatively short, open canopies. Results suggest that while all three missions will produce datasets useful for biomass mapping, tall, dense canopies such as those found in Sonoma County present the greatest challenges for all three missions, while steep slopes also prove challenging for single-date SAR-based biomass retrievals. Our methods provide guidance for the inter-comparison and validation of spaceborne biomass estimates through the use of airborne lidar reference maps, and could be repeated with on-orbit estimates in any area with high quality field plot and ALS data. These methods allow for regional interpretations and filtering of multi-mission biomass estimates toward improved wall-to-wall biomass maps through data fusion.

The Ice, Cloud, and Land Elevation Satellite – 2 mission: A global geolocated photon product derived from the Advanced Topographic Laser Altimeter System

The Ice, Cloud, and land Elevation Satellite – 2 (ICESat-2) observatory was launched on 15 September 2018 to measure ice sheet and glacier elevation change, sea ice freeboard, and enable the determination of the heights of Earth's forests. ICESat-2's laser altimeter, the Advanced Topographic Laser Altimeter System (ATLAS) uses green (532 nm) laser light and single-photon sensitive detection to measure time of flight and subsequently surface height along each of its six beams. In this paper, we describe the major components of ATLAS, including the transmitter, the receiver and the components of the timing system. We present the major components of the ICESat-2 observatory, including the Global Positioning System, star trackers and inertial measurement unit. The ICESat-2 Level 1B data product (ATL02) provides the precise photon round-trip time of flight, among other data. The ICESat-2 Level 2A data product (ATL03) combines the photon times of flight with the observatory position and attitude to determine the geodetic location (i.e. the latitude, longitude and height) of the ground bounce point of photons detected by ATLAS. The ATL03 data product is used by higher-level (Level 3A) surface-specific data products to determine glacier and ice sheet height, sea ice freeboard, vegetation canopy height, ocean surface topography, and inland water body height.

Effects of Secondary Forest Succession on Amphibians and Reptiles: A Review and Meta-analysis

Over the past century, humans have cleared the Earth's forests at an alarming rate and intensity. The majority of global forest cover is categorized as secondary forest, and it is becoming increasingly important to consider secondary forests in addition to old-growth forest in conservation planning for biota. We reviewed the literature to synthesize information on amphibian and reptile communities during secondary forest succession. We summarized literature on mechanisms of community change during forest succession and conducted a meta-analysis to estimate effect sizes for species richness and abundance in human-modified landscapes (agriculture, pasture, and plantation) and old-growth forests compared to regenerating secondary forests. Studies reported strong support for differences in species composition among human-modified landscapes, secondary forest, and old-growth forest as well as species-specific responses to successional forest change. Secondary forest generally had higher species richness and ab...

Self-ignition of natural fuels: Can wildfires of carbon-rich soil start by self-heating?

Carbon-rich soils, like histosols or gelisols, cover more than 3% of the Earth's land surface, and store roughly three times more carbon than the Earth's forests. Carbon-rich soils are reactive porous materials, prone to smouldering combustion if the inert and moisture contents are low enough. An example of soil combustion happens in peatlands, where smouldering wildfires are common in both boreal and tropical regions. This work focuses on understanding soil ignition by self-heating, which is due to spontaneous exothermic reactions in the presence of oxygen under certain thermal conditions. We investigate the effect of soil inorganic content by creating under controlled conditions soil samples with inorganic content (IC) ranging from 3% to 86% of dry weight: we use sand as a surrogate of inorganic matter and peat as a surrogate of organic matter. This range is very wide and covers all IC values of known carbon-rich soils on Earth. The experimental results show that self-heating ignition in different soil types is possible, even with the 86% inorganic content, but the tendency to ignite decreases quickly with increasing IC. We report a clear increase in ambient temperature required for ignition as the IC increases. Combining results from 39 thermostatically-controlled oven experiments, totalling 401h of heating time, with the Frank-Kamenetskii theory of ignition, the lumped chemical kinetic and thermal parameters are determined. We then use these parameters to upscale the laboratory experiments to soil layers of different thicknesses for a range of ambient temperatures ranging from 0°C to 40°C. The analysis predicts the critical soil layer thicknesses in nature for self-ignition at various possible environmental temperatures. For example, at 40°C a soil layer of 3% inorganic content can be ignited through self-heating if it is thicker than 8.8m, but at 86% IC the layer has to be 1.8km thick, which is impossible to find in nature. We estimate that the critical IC for a ambient temperature of 40°C and soil thickness of 50m is 68%. Because those are extreme values of temperature and thickness, no self-heating ignition of soil can be expected above the 68% threshold of inorganic content. This is the first in-depth experimental quantification of soil self-heating and shows that indeed it is possible that wildfires are initiated by self-heating in some soil types and conditions.

The Economics of Forest Carbon Offsets

Annually, nearly 500 gigatonnes of CO2 are exchanged between terrestrial ecosystems and the atmosphere, and this exchange is clearly affected by human activities related to the Earth's forests. Governments are therefore willing to draft legislation incentivizing forest activities that sequester carbon to combat climate change. In this review, we examine issues related to the creation of carbon offset credits through forest conservation, burning of wood biomass in lieu of fossil fuels, and intensive commercial management that accounts for all carbon fluxes, including postharvest. In doing so, we study the costs of monitoring, measuring, and contracting; the principal-agent problem; and questions related to life cycle analyses of CO2. We can only conclude that greater care is likely needed in the future to identify carbon offsets from forestry activities if these are to be traded in emissions markets.

Forest management through community participation in Sri Lanka (with reference to Kurunegala district)

A forest is an area with a high density of trees (or, historically, an area set aside for hunting). Plantcommunities covering large areas of the globe provide carbon-sink, oxygen-release, habitat, and soilretentionfunctions. Therefore, Earth's forests constitute one of the most important aspects of ourbiosphere.In response to escalating concerns about the degradation of State-managed forests, developing countriesaround the world are increasingly promoting decentral ization of natural resource management. Fromthe State-centric policies that were promoted in different parts of the world in the mid-Zf)" century,the trend has shifted toward encouraging participatory systems of management by local communities.This shift has been prompted by recognition of the numerous problems associated with consolidatingall power in the hands of the State, and of the crucial, hitherto unrecognized, positive role played bylocal communities-albeit nudged by international shifts in policy.Isolated islands of forests in Sri Lanka have received the attention of both the state and the peoplebecause of their economic importance. Responsibility for forest management has been placed ontechnically trained officers in the public sector, the objective being to promote state regulation in theefficient management of forest resources. Sri Lanka's natural forest cover is now around 31% of theisland's 65,610 sq km, and natural closed canopy forests have dwindled to 22.5 % of the total landarea from 44 % in 1956. It is significant that tropical humid forests, which form the natural vegetationtype of the island's ever-wet southwestern quarter, have shrunk to about 9.5% of this region. Theseforests are also heavily fragmented and few are more than 10,000 ha in extent. Although much of theendemic species among both fauna and flora are concentrated in the wet zone, lowland rain forests ofthis region comprise about 1.9% of the island's land area.This research follows the manner in which State-driven, upwardly accountable, forest decentralizationprograms play out on the ground, and evaluates their impact on forests and local institutions, a topic ofmuch current concern and debate. In-depth field interviews with the communities provide us withinformation about the impact of these initiatives on local institutions. Non-wood forest products areimportant to people for a number of reasons. First, NWFPs are integral to the lifestyle of forestdependentcommunities. They fulfill basic requirements, provide gainful employment during lean periodsand supplement incomes from agriculture and wage labor. Medicinal plants have an important role inrural health.The objective of this paper is to explores forest management through community participation toprotect the forest in Sri Lanka. Up to now there is no local communities currently function under asituation of constraint, where they have not been delegated responsibilities. It has been collectedopinion from hundred families who lives around forest cover in Kurunegala district and 95% of peoplesaid that community participation is the best way to manage the forest in Sri Lanka. It can be takenexperience from India and Nepal for this program.

A Curiosity Moment for Tropical Biology?

I was truly amazed by the remarkable feat that NASA's Jet Propulsion Laboratory pulled off in landing the Curiosity rover on the surface of Mars. But it leaves me wondering whether we have ever spent a billion dollars examining any part of Earth's tropical rainforest. ![Figure][1] CREDIT: CHRISTIAN ZIEGLER/WIKIMEDIA COMMONS We remain ignorant of even the most basic properties of Earth's equatorial forests, such as the number of large mammal species (or invertebrates, fungi, and microbes) in a forest, and their life cycles. The information that we do have is biased toward small intensively studied areas, whereas the vast intervening areas remain largely unexamined. The most extensive global network of observation plots, managed by the Center for Tropical Forest Science, encompasses a tiny fraction of total forest area. Acquiring a comprehensive knowledge of these forests seems impossible. Yet so did walking on the Moon 50 brief years ago. There are tremendous technical challenges in navigating the canopy of the tropical rainforests. We need to view the study of rainforests as an engineering problem and develop the same kind of amazing technologies used to study the surface of Mars. I want to be able to hover in a little car above the trees. I want to release a small cat-like autonomous robot into the canopy and retrieve it a month later two kilometers away, all the while tracking its movements as it gathers samples and observations, downloading gigabytes of data each day. There would be tremendous opportunities to translate those technologies into useful applications on Earth. I am confident that the trickle down would be much more substantial than that from the space program. Are we really going to have a colony on the Moon? Do we really plan on escaping to the stars? We have a few challenges here on Earth that we need to face before we can ever truly fulfill those dreams. [1]: pending:yes

Forest disturbance and recovery: A general review in the context of spaceborne remote sensing of impacts on aboveground biomass and canopy structure

Abrupt forest disturbances generating gaps >0.001 km2 impact roughly 0.4–0.7 million km2 a−1. Fire, windstorms, logging, and shifting cultivation are dominant disturbances; minor contributors are land conversion, flooding, landslides, and avalanches. All can have substantial impacts on canopy biomass and structure. Quantifying disturbance location, extent, severity, and the fate of disturbed biomass will improve carbon budget estimates and lead to better initialization, parameterization, and/or testing of forest carbon cycle models. Spaceborne remote sensing maps large‐scale forest disturbance occurrence, location, and extent, particularly with moderate‐ and fine‐scale resolution passive optical/near‐infrared (NIR) instruments. High‐resolution remote sensing (e.g., ∼1 m passive optical/NIR, or small footprint lidar) can map crown geometry and gaps, but has rarely been systematically applied to study small‐scale disturbance and natural mortality gap dynamics over large regions. Reducing uncertainty in disturbance and recovery impacts on global forest carbon balance requires quantification of (1) predisturbance forest biomass; (2) disturbance impact on standing biomass and its fate; and (3) rate of biomass accumulation during recovery. Active remote sensing data (e.g., lidar, radar) are more directly indicative of canopy biomass and many structural properties than passive instrument data; a new generation of instruments designed to generate global coverage/sampling of canopy biomass and structure can improve our ability to quantify the carbon balance of Earth's forests. Generating a high‐quality quantitative assessment of disturbance impacts on canopy biomass and structure with spaceborne remote sensing requires comprehensive, well designed, and well coordinated field programs collecting high‐quality ground‐based data and linkages to dynamical models that can use this information.

Entomogenic Climate Change: Insect Bioacoustics and Future Forest Ecology

Rapidly expanding insect populations, deforestation and global climate change threaten to destabilize key planetary carbon pools, especially the Earth's forests, which link the micro-ecology of insect infestation to climate. To the extent mean temperature increases, insect populations accelerate deforestation. This alters climate via the loss of active carbon sequestration by live trees and increased carbon release from decomposing dead trees. A self-sustaining positive feedback loop can then emerge. Extensive field recordings demonstrate that bioacoustic communication plays a role in infestation dynamics and is likely to be a critical link in the feedback loop. These results open the way to novel detection and monitoring strategies and nontoxic control interventions.

Soil respiration in northern forests exposed to elevated atmospheric carbon dioxide and ozone

The aspen free-air CO2 and O3 enrichment (FACTS II-FACE) study in Rhinelander, Wisconsin, USA, is designed to understand the mechanisms by which young northern deciduous forest ecosystems respond to elevated atmospheric carbon dioxide (CO2) and elevated tropospheric ozone (O3) in a replicated, factorial, field experiment. Soil respiration is the second largest flux of carbon (C) in these ecosystems, and the objective of this study was to understand how soil respiration responded to the experimental treatments as these fast-growing stands of pure aspen and birch + aspen approached maximum leaf area. Rates of soil respiration were typically lowest in the elevated O3 treatment. Elevated CO2 significantly stimulated soil respiration (8-26%) compared to the control treatment in both community types over all three growing seasons. In years 6-7 of the experiment, the greatest rates of soil respiration occurred in the interaction treatment (CO2 + O3), and rates of soil respiration were 15-25% greater in this treatment than in the elevated CO2 treatment, depending on year and community type. Two of the treatments, elevated CO2 and elevated CO2 + O3, were fumigated with 13C-depleted CO2, and in these two treatments we used standard isotope mixing models to understand the proportions of new and old C in soil respiration. During the peak of the growing season, C fixed since the initiation of the experiment in 1998 (new C) accounted for 60-80% of total soil respiration. The isotope measurements independently confirmed that more new C was respired from the interaction treatment compared to the elevated CO2 treatment. A period of low soil moisture late in the 2003 growing season resulted in soil respiration with an isotopic signature 4-6 per thousand enriched in 13C compared to sample dates when the percentage soil moisture was higher. In 2004, an extended period of low soil moisture during August and early September, punctuated by a significant rainfall event, resulted in soil respiration that was temporarily 4-6 per thousand more depleted in 13C. Up to 50% of the Earth's forests will see elevated concentrations of both CO2 and O3 in the coming decades and these interacting atmospheric trace gases stimulated soil respiration in this study.

SEI: A Strategic Environment Initiative

SEI: A STRATEGIC ENVIRONMENT INITIATIVE Al Gore H.umankind has entered into a brand new relationship with our planet— a relationship fundamentally different from anything we have known before. Recent evidence of greenhouse gas buildup, forest land destruction, soil erosion, water and air pollution, stratospheric ozone depletion, and species extinction points to an unprecedented environmental disaster. And yet, so far, our political priorities remain remarkably unchanged. From Love Canal to the Exxon Valdez, news about our environmental vulnerability pours in. Around the world, the earth's forests are being destroyed at the rate of one football field per second. An enormous hole is opening in the ozone layer, reducing the earth's ability to protect life from deadly ultraviolet radiation. The extinction of species is occuring at such an unprecedented rate that more than half of them may disappear within our lifetimes. Chemical wastes, in growing volumes, seep downward to poison groundwater and upward to destroy the atmosphere's delicate balance. The huge quantities of carbon dioxide (CO,), methane, and chlorofluorocarbons (CFCs) currently being dumped in the atmosphere are trapping heat and raising global temperatures. Until now, environmental considerations, if they have been taken into account at all, have usually taken second place to the requirements of economic development. The consequence of this neglect has been Al Gore is United States Senator from Tennessee and chairman of the Science, Technology , and Space Subcommitee of the Senate Commerce Committee. As a Representative in 1981, Mr. Gore co-chaired the first U.S. House of Representatives' hearing on the greenhouse effect. 59 60 SAIS REVIEW environmental deterioration at the local, regional, and now even global levels. This process threatens not only the quality of life, but life itself. The global environment has thus become an issue of national security. For that reason, I have proposed a commensurate response: a Strategic Environment Initiative (SEI). The Price of Development: An Environment in Crisis The immediate effects of environmentally irresponsible forms of development have reached a point where they cannot be ignored. Indeed , environmental deterioration now presses the limits of our physical tolerance. When billions of people are affected daily by its consequences —from air and water pollution, chemical dumping, and solid wastes—a change of attitude eventually occurs and ultimately influences the political agenda, with increasing force and effectiveness. In the wealthiest nations, the result has been a shift in thinking about the value of economic growth in relation to environmental costs. There is still wide variation in the behavior of these nations, but the trend shows an increasing readiness to accept the need for tempering development on behalf of the environment. This trend can be seen at every level of political activity, and is affecting local, national, and international affairs. The less wealthy and impoverished nations have less freedom of choice. Yet, even there, a growing awareness exists that economic development , based on unrestrained exploitation of the environment, brings with it long-term economic penalties, which will soon impose themselves. A gradual acceptance of the need for harvesting natural resources in an environmentally and economically sustainable manner is likely to follow. Regrettably, in the vast majority of Third World nations, that acceptance will necessarily remain only an aspiration— a priority that will have to take its place behind the more pressing problem ofsatisfying basic human needs. The increasing sensitivity of governments towards environmental problems is good news. Unfortunately, it is not enough. The single most significant environmental threat we face probably cannot be solved by marginal changes in behavior and defies action even by national governments . This is the phenomenon of global warming and the related problem of widespread climatic change. It is increasingly clear that this will be one of the penalties for unrestrained economic development. It is also clear that without radical changes in our methods of development the consequences of our present actions will be severe enough to threaten international security. STRATEGIC ENVIRONMENT INITIATIVE 61 Given present trends, by the middle of the next century or sooner greenhouse gas emissions will have doubled the pre-Industrial Revolution level of carbon dioxide in the atmosphere. This is the "CO1 doubling" benchmark scientists have used to determine the additional greenhouse effect on...

Performance analysis of image processing algorithms for classification of natural vegetation in the mountains of Southern California

The earth's forests fix carbon from the atmosphere during photosynthesis. Scientists are concerned that massive forest removals may promote an increase in atmospheric carbon dioxide, with possible global warming and related environmental effects. Space-based remote sensing may enable the production of accurate world forest maps needed to examine this concern objectively. To test the limits of remote sensing for large-area forest mapping, we use Landsat data acquired over a site in the forested mountains of southern California to examine the relative capacities of a variety of popular image processing algorithms to discriminate different forest types. Results indicate that certain algorithms are best suited to forest classification. Differences in performance between the algorithms tested appear related to variations in their sensitivities to spectral variations caused by background reflectance, differential illumination, and spatial pattern by species. Results emphasize the complexity between the land-cover regime, remotely sensed data and the algorithms used to process these data.