Top 20 NRS Pubshttps://treesearch.fs.fed.us/pubs/Top 20 NRS Pubsen-usMon, 23 Jul 2018 03:50:39 +0000Effects of Adult Feeding and Overwintering Conditions on Energy Reserves and Flight Performance of Emerald Ash Borer (Coleoptera Buprestidae)https://treesearch.fs.fed.us/pubs/56475Emerald ash borer Agrilus planipennis Fairmaire (Coleoptera Buprestidae) an invasive beetle from Asia spreads through humanmediated movement and active flight. The effects of adult feeding and overwintering conditions on A. planipennis energy reserves (e.g. lipid glycogen and sugars) and flight are poorly understood. We conjectured that the potential energetic demands associated with the production of cryoprotectants might affect dispersal capacity and partially explain slower spread of A. planipennis in Minnesota than in the other states. Two studies sought to measure the effects of adult feeding on lipid content and flight capacity. Adult A. planipennis were fed shamel ash Fraxinus uhdei Wenzig leaves for 020 d after emergence and half were flown on a custom flight mill for 24 h before being frozen for comparative lipid analysis with a control group. The second study compared the effects of adult feeding on energy reserves and flight capacity of A. planipennis that were originally from St. Paul Minnesota but overwintered in infested logs placed in Grand Rapids Minnesota (low winter temperature 34C) or St. Paul Minnesota (26.3C). Live adults consumed foliage at a constant rate but lipid content (percentage of fresh mass) did not change with increases in feeding or flight. Adult glycogen content declined with flight and increased only slightly with feeding. Overwintering location affected survival rates but not energy reserves or flight capacity. These results suggest that the flight capacity of A. planipennis is largely determined before emergence with no differences in energy reserves after cryoprotectant investment.Fri, 20 Jul 2018 09:54:21 +0000Improved biosecurity surveillance of nonnative forest insects a review of current methodshttps://treesearch.fs.fed.us/pubs/56480Biosecurity surveillance has been highlighted as a key activity to discover nonnative species at the initial stage of invasion. It provides an opportunity for rapidly initiating eradication measures and implementing responses to prevent spread and permanent establishment reducing costs and damage. In importing countries three types of biosecurity activities can be carried out border surveillance targets the arrival stage of a nonnative species at pointsofentry for commodities postborder surveillance and containment target the establishment stage but postborder surveillance is carried out on a large spatial scale whereas containment is carried out around infested areas. In recent years several surveillance approaches such as baited traps sentinel trees biosurveillance with sniffer dogs or predatory wasps electronic noses acoustic detection laser vibrometry citizen science genetic identification tools and remote sensing have been developed to complement routine visual inspections and aid in biosecurity capacity. Here we review the existing literature on these tools highlight their strengths and weaknesses and identify the biosecurity surveillance categories and sites where each tool can be used more efficiently. Finally we show how these tools can be integrated in a comprehensive biosecurity program and discuss steps to improve biosecurity.Fri, 20 Jul 2018 13:44:16 +0000Inter and Intrasexual Interactions in Anoplophora glabripennis (Coleoptera Cerambycidae) and the Impact of Different Sex Ratioshttps://treesearch.fs.fed.us/pubs/56482The behaviors of Anoplophora glabripennis (Motschulsky) (Coleoptera Cerambycidae) during inter and intrasexual interactions between both solitary and paired individuals at different sex ratios were observed on Acer platanoides L. (Sapindales Sapindaceae) branches in the laboratory. Intrasexual contact was generally ignored by females but between males resulted in battles from which one male ultimately retreated. When male size differed larger males won battles whereas equally sized males split the wins and battled longer. When males initiated intersexual contact they quickly found and mounted the female. The female apparently determined if and how long the male could copulate with her by controlling access to her genital opening and males would eventually dismount if the female remained unreceptive. After successful copulation males ignored female intruders and fought off male challengers generally without dismounting. Some males dismounted females without attempting to copulate. Individual age and size were not predictive of either female or male choice in a mate. Mating duration was affected by both female receptivity and sex ratios present. Male interruptions of the pair shortened time in copula. Maleskewed sex ratios (1F2M) significantly shortened the time a male would stay with an unreceptive female. Femaleskewed sex ratios (2F1M) did not impact mating duration. Probability of dispersal both from and within the branch was greater for smaller individuals of both sexes and for males when sex ratios were maleskewed. This information demonstrates how reproductive activity might be impacted as population densities decline during efforts at eradication of this species in North America.Fri, 20 Jul 2018 14:35:37 +0000Kirtlands warbler winter habitat changes across the Bahamian Archipelago in response to future climatecondition scenarioshttps://treesearch.fs.fed.us/pubs/56481Changing climate may impact species through several processes including phenologic shifts in seasonal timing of food supplies. These temporal changes can create trophic mismatches for species during major lifecycle events such as migration. For longdistance NeotropicalNearctic migratory songbirds body condition prior to migration is related to quality and quantity of food supply which is a function of precipitation and temperature conditions on the wintering grounds. We assessed how future climatechange scenarios might affect wintering habitat of Setophaga kirtlandii (Kirtlands Warbler) on the Bahamian Archipelago. We used ensembles of generalcirculation models to project precipitation and temperature patterns across the archipelago over the winter period from baseline average until the end of the century. We also used topography layers to define Kirtlands Warbler winter habitat (open lands) and then made landcoverloss projections for open lands using 1 and 2m sealevelrise scenarios. Our results indicate that the Bahamian islands used by Kirtlands Warbler will become warmer and wetter during the winter months except during March when central islands are predicted to go through a drying trend. Moreover our models predict that the greatest habitat loss of coastal open land due to sealevel rise will occur on the northern lowerelevation islands. If we consider both potential changes in habitat quality and quantity from changing climate the northcentral islands which currently contain the majority of the wintering population are likely the critical islands on which to focus climateadaptation strategies. To help land managers spatially plan for habitat alteration continued processing of highresolution imagery is necessary for finer assessments of potential habitat loss changes in habitat quality and redistribution of habitats across this island system in response to changing environmental conditions and sealevel rise.Fri, 20 Jul 2018 13:50:08 +0000Modest Effects of Host on the Cold Hardiness of Emerald Ash Borerhttps://treesearch.fs.fed.us/pubs/56476The emerald ash borer Agrilus planipennis Fairmaire is invading North America and Europe but has not yet reached its ultimate distribution. Geographic differences in host availability and winter temperatures might affect where this species will occur. In central North America black ash (Fraxinus nigra) is more abundant than green ash (F. pennsylvanica) at northern latitudes but much of our current understanding of A. planipennis cold tolerance is based on observations of overwintering larvae from green ash. The effects of black and green ash on the cold hardiness of A. planipennis larvae were measured over three winters. Supercooling point the temperature at which insect bodily fluids spontaneously begin to freeze was marginally greater for larvae from artificiallyinfested black ash than green ash in one trial but not in three others. Host species also did not consistently affect mortality rates after larval exposure to subzero temperatures but larvae from black ash were less cold hardy than larvae from green ash when there were differences. Comparisons of mortality rates among chilled (unfrozen) and frozen larvae indicated that overwintering A. planipennis larvae are primarily freeze avoidant and this cold tolerance strategy is unaffected by host. All of our studies suggest that A. planipennis larvae from black ash are not more cold hardy that larvae from green ash. Where temperatures annually decline below 30 C overwintering morality may substantially affect the population dynamics and future impacts from this invasive alien species.Fri, 20 Jul 2018 10:00:56 +0000Optimization of Agrobacteriummediated genetic transformation of Fraxinus nigra and development of black ash for possible emerald ash borer resistancehttps://treesearch.fs.fed.us/pubs/56462Emerald ash borer (EAB Agrilus planipennis Fairmaire) is the most devastating insect pest of North American ash species including black ash (Fraxinus nigra Marsh.). As a first step in an effort to develop transgenic black ash plants resistant to EAB we successfully established an efficient Agrobacteriummediated transformation system for black ash hypocotyls. Kanamycin and timentin at 40 and 300 mg L1 respectively were most effective to select transformed explants and control excess Agrobacterium growth. Using a plant transformation vector harboring the enhanced green fluorescent protein (eGFP) gene the effects of Agrobacterium strain bacterial density and the concentration of Silwet L77 on transformation efficiency were evaluated. The best result was obtained when Agrobacterium strain EHA105 was used at a density of OD600 1.0. Silwet L77 failed to promote transformation frequency and showed an adverse effect at higher concentrations (gt0.015). Using this optimized transformation system transgenic black ash shoots expressing a synthetic Bacillus thuringiensis toxin gene (cry8D2) were regenerated. Although no morphological abnormality was observed transgenic shoots showed severe growth restriction. Three independent transgenic lines were selected for further assessment. All selected lines contained two copies of the cry8D2 gene and the expression of the transgene was verified in transcript and protein levels. These transgenic shoots can be used for future bioassay to evaluate its efficacy against EAB.Thu, 19 Jul 2018 07:39:10 +0000Potential Impacts of Emerald Ash Borer Biocontrol on Ash Health and Recovery in Southern Michiganhttps://treesearch.fs.fed.us/pubs/56483Emerald ash borer (EAB) is an invasive beetle that kills native North American ash species threatening their persistence. A classical biological control program for EAB was initiated in 2007 with the release of three specialized EAB parasitoids. Monitoring changes in the health and regeneration of ash where EAB biocontrol agents have been released is critical for assessing the success of EAB biocontrol and predicting future changes to the ash component of North American forests. We sampled release and control plots across southern Michigan over a threeyear period to measure ash health and recruitment to begin assessing the longterm impact of EAB biological control on ash populations. We noted a reduced mortality of larger trees between 2012 and 2015 in release plots compared to control plots and increases in ash diameter but our results were otherwise inconsistent. Ash regeneration was generally higher in release plots compared to control plots but highly variable among sites suggesting some protection of ash saplings from EAB by parasitoids. We conclude that EAB biocontrol is likely to have a positive effect on ash populations but that the study duration was not long enough to definitively deduce the longterm success of the biocontrol program in this region.Fri, 20 Jul 2018 14:40:48 +0000Reproduction and potential range expansion of walnut twig beetle across the Juglandaceaehttps://treesearch.fs.fed.us/pubs/56469Biological invasions by insects that vector plant pathogens have altered the composition of natural and urban forests. Thousand cankers disease is a new recent example and is caused by the complex of walnut twig beetle Pityophthorus juglandis and the fungus Geosmithia morbida on susceptible hosts notably some Juglans spp. and Pterocarya spp. Host colonization by P. juglandis may be particularly important for disease development but the beetles host range is not known. In the United States and Italy this insect has expanded its geographic range by colonizing nave hosts. The objective of this study was to characterize limits to and variation within the host range of P. juglandis and infer the extent to which hosts might constrain the geographic distribution of the insect. We examined colonization and reproduction by P. juglandis in nochoice laboratory experiments with 11 Juglans spp. one Pterocarya sp. and two Carya spp. over 2 years and found that all but the Carya spp. were hosts. Reproduction was generally greater on Juglans californica J. hindsii and J. nigra than on J. ailantifolia J. cathayensis J. cinerea J. major J. mandshurica J. microcarpa or J. regia. Escape of an insect vector into populations of evolutionarynave hosts can facilitate rapid range expansion by the pest and massive mortality to hosts. Multicontinental plantings of suitable species may facilitate geographic range expansion of P. juglandis and place other native Juglans spp. at risk.Thu, 19 Jul 2018 13:11:44 +0000Responses of Soil Labile Organic Carbon to a Simulated Hurricane Disturbance in a Tropical Wet Foresthttps://treesearch.fs.fed.us/pubs/56474Hurricanes are an important disturbance in the tropics that can alter forest ecosystem properties and processes. To understand the immediate influence of hurricane disturbance on carbon cycling we examined soil labile organic carbon (LOC) in a Canopy Trimming Experiment (CTE) located in the Luquillo Experimental Forest of Puerto Rico. We trimmed tree canopy and deposited debris (CTDD) on the forest ground of the treatment plots in December 2014 and collected floor mass samples and 010 cm soil samples three weeks before the treatment as well as at scheduled intervals for 120 weeks after the treatment. Within the first week following the CTDD treatment the mean soil microbial biomass carbon (MBC) and soil LOC in the CTDD plots were significantly greater than in the control plots (soil MBC 2.56 gkg versus 1.98 gkg soil LOC 9.16 gkg versus 6.44 gkg respectively) and the mean turnover rates of soil LOC in the CTDD plots were significantly faster than in the control plots. The measured indices fluctuated temporally more in the CTDD plots than in the control plots especially between the 12th and 84th week after the CTDD treatment. The treatment effect on soil LOC and its turnover rate gradually disappeared after the 84th week following the treatment while higher levels of soil MBC in the CTDD plots than in the control plots remained high even at the 120th week. Our data suggest that hurricane disturbance can accelerate the cycling of soil LOC on a short temporal scale of less than two years but might have a longer lasting effect on soil MBC in a tropical wet forest.Wed, 18 Jul 2018 16:36:32 +0000Using social media to predict air pollution during California wildfireshttps://treesearch.fs.fed.us/pubs/56459Wildfires have significant effects on human populations worldwide. Smoke pollution in particular from either prescribed burns or uncontrolled wildfires can have profound health impacts such as reducing birth weight in children and aggravating respiratory and cardiovascular conditions. Scarcity in the measurements of particulate matter responsible for these public health issues makes addressing the problem of smoke dispersion challenging especially when fires occur in remote regions. Previous research has shown that in the case of the 2014 King fire in California crowdsourced data can be useful in estimating particulate pollution from wildfire smoke. In this paper we show that the previous model continues to provide good estimates when extended statewide to cover several wildfires over an entire season in California. Moreover adding the semantic information contained in the social media data to the predictive model significantly increases model accuracy indicating a confluence of social and spatiotemporal data.Wed, 18 Jul 2018 13:14:58 +0000Introductionhttps://treesearch.fs.fed.us/pubs/56449For millennia forests have been a strategic resource for mankind providing building material for houses ships and mining household and industrial fuel hunting grounds and grazing opportunities for cattle. Despite its strategic importance forest management was often not sustainable. Many European countries have a long history of deforestation and overexploitation of forest resources. North America has also seen substantial deforestation since European colonization. The principles of sustainable forest management were formulated around 1700 by Von Carlowitz in Germany (1713). Centuries later the concept of sustainability became popular under the term sustainable development as coined by the Report of the World Commission on Environment and Development Our Common Future also known as the Brundtland report (httpwww.undocuments.netourcommonfuture.pdf).Mon, 16 Jul 2018 14:30:44 +0000United States of Americahttps://treesearch.fs.fed.us/pubs/56477ln the United States of America (USA) forest land is defined with respect to four criteria (1) minimum area of 0.4 ha (2) minimum crown cover of 10 (3) minimum width of 36.6 m and (4) forest use. Total forest land currently exceeds 310 million ha and has generally been increasing since the 1920s despite a near tripling of the human population. Currently more than 30 of the country is characterized as forest land with 58 of it in various categories of private ownership. Unlike in many European countries private forest land owners in the USA have considerable freedom to convert their land from forest to nonforest uses and viceversa in response to varying commodity prices and other factors. This feature of private land ownership at least partially explains substantially varying local forest areas over time.Fri, 20 Jul 2018 10:07:53 +0000Integration of remotesensing and groundbased observations for estimation of emissions and removals of greenhouse gases in forests Methods and guidance from the Global Forest Observations Initiative edition 2.0https://treesearch.fs.fed.us/pubs/56461The Global Forest Observations Initiative (GFOI) was established by GEO in 2011 to assist countries to produce reliable consistent reports on change in forest cover and forest use and associated anthropogenic greenhouse gas emissions and removals.Thu, 19 Jul 2018 07:29:06 +0000Propagating uncertainty through individual tree volume model predictions to largearea volume estimateshttps://treesearch.fs.fed.us/pubs/56464Key message. The effects on largearea volume estimates of uncertainty in individual tree volume model predictions were negligible when using simple random sampling estimators for largearea estimation but nonnegligible when using stratified estimators which reduced the effects of sampling variability. Context. Forest inventory estimates of tree volume for large areas are typically calculated by adding model predictions of volumes for individual trees at the plot level and calculating the per unit area mean over plots. The uncertainty in the model predictions is generally ignored with the result that the precision of the largearea volume estimate is optimistic. Aims. The primary objective was to estimate the effects on largearea volume estimates of volume model prediction uncertainty due to diameter and height measurement error parameter uncertainty and model residual variance. Methods. Monte Carlo simulation approaches were used because of the complexities associated with multiple sources of uncertainty the nonlinear nature of the models and heteroskedasticity. Results. The effects of model prediction uncertainty on largearea volume estimates of growing stock volume were negligible when using simple random sampling estimators. However with stratified estimators that reduce the effects of sampling variability the effects of model prediction uncertainty were not necessarily negligible. The adverse effects of parameter uncertainty and residual variance were greater than the effects of diameter and height measurement errors. Conclusion. The uncertainty of largearea volume estimates that do not account for model prediction uncertainty should be regarded with caution.Thu, 19 Jul 2018 08:22:16 +0000Suitability of Global Forest Change data to report forest cover estimates at national level in Gabonhttps://treesearch.fs.fed.us/pubs/56450For purposes of greenhouse gas emissions (GHG) accounting estimation of deforestation area in tropical countries often relies on satellite remote sensing in the absence of National Forest Inventories (NFI). Gabon has recently launched a National Climate Action Plan with the intent of establishing a National Forest Monitoring System that meets the Intergovernmental Panel on Climate Change (IPCC) 2006 guidelines for the Agriculture Forestry and Other Land Use (AFOLU) sector. The assessment of areas of forest cover and forest cover change is essential to estimate activity data defined as areas of various categories of land use change by the IPCC guidelines. An appropriately designed probability sample can be used to estimate forest cover and net change and their associated uncertainties and express themin the form of confidence intervals at selected probability thresholds as required in the IPCC 2006 guidelines and for reporting to the United Nations Framework Convention on Climate Change (UNFCCC). However walltowall mapping is often required to provide a comprehensive assessment of forest resources and as input to land use plans for management purposes but walltowall approaches are more expensive than a sample based approach based on visual interpretation and require specialized equipment and staff. The recent release of the University ofMaryland (UMD) Global Forest Change (GFC)map products could be an alternative for tropical countries wishing to develop their own walltowall forest map products but without the resources to do so. Therefore the aimof this study is to assess the feasibility of replacing nationalwalltowall forest maps with forest maps obtained from the UMD GFC initiative. Amodel assisted regression (MAR) estimator was applied using the combination of reference data obtained from a probability sample and forest cover and forest cover change maps either (i) produced nationally or (ii) obtained fromthe UMD GFC data. The resulting activity data are potentially more accurate than the SRS estimate and provide an assessment of the precision of the estimate which is not available from map accuracy indices alone. Results obtained for 2000 and 2010 for both the national and UMD GFC datasets confirm the high level of forest cover in Gabon more than 23.5 million ha representing approximately 88.5 of the country. Although the UMD GFC dataset provides a reliablemeans of producing area statistics at national level combined with appropriate sample reference data thus offering an alternative to nationally produced datasets (i) the classification errors associated with the Global dataset have nonnegligible effects on both the estimate and the precision which supports the more general statement that map data should not be used alone to produce area estimates and (ii) the maps obtained fromthe UMD GFC dataset require specific calibration of the tree cover percentage representing a nonnegligible effort requiring specialized staff and equipment. Guidelines on howto use and further improve UMD GFC maps for national reporting are suggested. However this additional effort would still most likely be less than the production of national based maps.Mon, 16 Jul 2018 14:57:20 +0000United States of Americahttps://treesearch.fs.fed.us/pubs/56479The national forest inventory (NFI) of the United States of America (USA) is conducted by the Forest Inventory and Analysis (FIA) programme of the U.S. Forest Service an agency of the U.S. Department of Agriculture. The FIA programme has been in continuous existence since 1928 and is the only organisation that collects compiles archives analyses and publishes state regional and national forest information on all ownerships of forest land in the USA. The history of the programme is documented in numerous publications including LaBau et al. (2007) Gregoire (1992) and Yan Hooser et al. (1992) recent history is documented in McRoberts et al. (2005 2010) and Bechtold and Patterson (2005).Fri, 20 Jul 2018 13:07:14 +0000Wood resources assessment beyond Europehttps://treesearch.fs.fed.us/pubs/56460Forest ecosystems provide wood and many other services that contribute significantly to human wellbeing at local national and global scales. These contributions include the conservation of soil and water resources mitigation of the effects of global climate change conservation of biological diversity improvement of urban living conditions protection of natural and cultural heritage subsistence resources for many rural and indigenous communities generation of employment as well as recreational opportunities (MEA 2005). Due to the importance of forests for humanity the evolution of the worlds forest functions and services are a major concern in international agreements and processes that address environmental and development issues such as the United Nations Framework Convention on Climate Change (UNFCCC) the Convention on Biological Diversity (CBD) the United Nations Forum on Forests (UNFF) or the Sustainable Development Goals (SDGs).Thu, 19 Jul 2018 07:10:25 +0000Estimating and mapping forest structural diversity using airborne laser scanning datahttps://treesearch.fs.fed.us/pubs/56451Among the wide array of terrestrial habitats forest andwooded lands are the richest fromboth biological and genetic points of view because of their inherent structural and compositional complexity and diversity. Although species composition is an important biodiversity feature forest structuremay be evenmore relevant for biodiversity assessments because a diversified structure is likely to have more niches which in turn host more species and contribute to a more efficient use of available resources. Structure plays a major role as a diversity indicator formanagement purposes where maps of forest structural diversity are of great utility when planning conservation strategies. Airborne laser scanning (ALS) data have been demonstrated to be a reliable and valid source of information for describing the threedimensional structure of forests. Using ALS metrics as predictor variables we developed regression models for predicting indices of forest structural diversity for a study area in Molise Italy. The study had two primary objectives (i) to estimate indices of structural diversity for the entire study area and (ii) to construct maps depicting the spatial pattern of the structural diversity indices. Our results demonstrate the utility of simple linear models using ALS data for improving areal estimates of mean structural diversity and the resulting maps capture the patterns of structural diversity in the study area.Mon, 16 Jul 2018 15:05:05 +0000The effects of uncertainty in individual tree volume model predictions on large area estimates of forest volumehttps://treesearch.fs.fed.us/pubs/56478Greenhouse gas inventories for the forestry sector rely on large area eslimates of tree biomass. These estimates are calculated by predicting volumes of individual trees multiplying by a biomass conversion factor adding individual tree biomass estimates at the plot level and then averaging over plots to obtain the large area estimates. However the uncertainty in the model prediction is generally ignored with the result that the precision of the large area estimates is overestimated. The study objetive was to estimate the effectsof modelrelated uncertainties on large area volumes estimates for study areas in the state of Minnesota USA and the state of Santa Catarina Brazil. Monte Carlo simulation approaches were used because of the complexities associated with multiple sources of uncertainty and the nonlinear nature of the models. The effects of uncertainty in model predictions on the large area volumes estimates were small although the results depend heavily on sample size and quality of fit models.Fri, 20 Jul 2018 12:52:07 +0000Using the regression estimator with Landsat data to estimate proportion forest cover and net proportion deforestation in Gabonhttps://treesearch.fs.fed.us/pubs/56468Forest cover maps were produced for the Gabonese Agency for Space Studies and Observations (AGEOS) for 1990 2000 and 2010 for an area of approximately 102000 km2 corresponding to 38 of the total area of Gabon and representative of the range of human pressure on forest resources. The maps were constructed using a combination of a semiautomated classification procedure and manual enhancements to ensure the greatest possible accuracy. A twostage area frame sampling approach was adopted to collect reference data for assessing the accuracy of the forest cover maps and to estimate proportion forest cover and net proportion deforestation. A total of 251 2 2 km segments or primary sample units (PSUs) were visually interpreted by a team of photointerpreters independently from the map production team to produce a reference dataset representing about 1 of the study area. Paired observations were extracted from the forest cover map and the reference data for a random selection of 50 secondary sample units (SSUs) in the form of pixels within each PSU. Overall map accuracieswere greater than 95. PSU and SSU outputs were used to estimate proportion forest cover and net proportion deforestation using both direct expansion and modelassisted regression (MAR) estimators. All proportion forest cover estimates were similar but the variances of the MAR estimates were smaller than variances for the direct expansion estimates by factors as great as 50. In addition SSUlevel estimates had standard errors slightly greater than those of PSUlevel estimates but the differences were small particularly when auxiliary variables were obtained from forest cover maps. Therefore a twostage sampling approach was justified for collecting a reliable forest cover reference dataset for estimating proportion forest cover area and net proportion deforestation. Finally despite large overall map accuracies net proportion deforestation estimates obtained from the maps alone can be misleading as indicated by the finding that the MAR estimates which included adjustment for bias estimates were twice the nonadjusted map estimates for the periods 19902000 and 19902010. The results confirmed the expected generally small level of net deforestation for Gabon. However loss of forest cover appears to have almost stopped in the last 10 years. One explanation could be the creation of national parks and the implementation of forest concession management plans from 2000 onward but this should be further explored.Thu, 19 Jul 2018 13:04:16 +0000