Добірка наукової літератури з теми "Lao tropical forests"

Forest stand height (FSH), or average canopy height, serves as an important indicator for forest monitoring. The information provided about above-ground biomass for greenhouse gas emissions reporting and estimating carbon storage is relevant for reporting for Reducing Emissions from Deforestation and Forest Degradation (REDD+). A novel forest height estimation method utilizing a fusion of backscatter and Interferometric Synthetic Aperture Radar (InSAR) data from JAXA’s Advanced Land Observing Satellite Phased Array type L-band Synthetic Aperture Radar (ALOS PALSAR) is applied to a use case in Savannakhet, Lao. Compared with LiDAR, the estimated height from the fusion method had an RMSE of 4.90 m and an R2 of 0.26. These results are comparable to previous studies using SAR estimation techniques. Despite limitations of data quality and quantity, the Savannakhet, Lao use case demonstrates the applicability of these techniques utilizing L-band SAR data for estimating FSH in tropical forests and can be used as a springboard for use of L-band data from the future NASA-ISRO SAR (NISAR) mission.

Terrestrial mammals are a key component of tropical forest communities as indicators of ecosystem health and providers of important ecosystem services. However, there is little quantitative information about how they change with local, regional and global threats. In this paper, the first standardized pantropical forest terrestrial mammal community study, we examine several aspects of terrestrial mammal species and community diversity (species richness, species diversity, evenness, dominance, functional diversity and community structure) at seven sites around the globe using a single standardized camera trapping methodology approach. The sites—located in Uganda, Tanzania, Indonesia, Lao PDR, Suriname, Brazil and Costa Rica—are surrounded by different landscape configurations, from continuous forests to highly fragmented forests. We obtained more than 51 000 images and detected 105 species of mammals with a total sampling effort of 12 687 camera trap days. We find that mammal communities from highly fragmented sites have lower species richness, species diversity, functional diversity and higher dominance when compared with sites in partially fragmented and continuous forest. We emphasize the importance of standardized camera trapping approaches for obtaining baselines for monitoring forest mammal communities so as to adequately understand the effect of global, regional and local threats and appropriately inform conservation actions.

Abstract. Disturbances, such as extreme weather events, fires, floods, and biotic agents, can have strong impacts on the dynamics and structures of tropical forests. In the future, the intensity of disturbances will likely further increase, which may have more serious consequences for tropical forests than those we have already observed. Thus, quantifying aboveground biomass loss of forest stands due to stem mortality (hereafter biomass loss rate) is important for the estimation of the role of tropical forests in the global carbon cycle. So far, the long-term impacts of altered stem mortality on rates of biomass loss have not been adequately described. This study aims to analyse the consequences of long-term elevated stem mortality rates on forest dynamics and biomass loss rate. We applied an individual-based forest model and investigated the impacts of permanently increased stem mortality rates on the growth dynamics of humid, terra firme forests in French Guiana. Here, we focused on biomass, leaf area index (LAI), forest height, productivity, forest age, quadratic mean stem diameter, and biomass loss rate. Based on the simulation data, we developed a multiple linear regression model to estimate biomass loss rates of forests in different successional states from the various forest attributes. The findings of our simulation study indicated that increased stem mortality altered the succession patterns of forests in favour of fast-growing species, which increased the old-growth forests' gross primary production, though net primary production remained stable. The stem mortality rate had a strong influence on the functional species composition and tree size distribution, which led to lower values in LAI, biomass, and forest height at the ecosystem level. We observed a strong influence of a change in stem mortality on biomass loss rate. Assuming a doubling of stem mortality rate, the biomass loss rate increased from 3.2 % yr−1 to 4.5 % yr−1 at equilibrium. We also obtained a multidimensional relationship that allowed for the estimation of biomass loss rates from forest height and LAI. Via an example, we applied this relationship to remote sensing data on LAI and forest height to map biomass loss rates for French Guiana. We estimated a countrywide mean biomass loss rate of 3.0 % yr−1. The approach described here provides a novel methodology for quantifying biomass loss rates, taking the successional state of tropical forests into account. Quantifying biomass loss rates may help to reduce uncertainties in the analysis of the global carbon cycle.

Leaf Area Index (LAI) has been defined as the total leaf area (one-sided) in relation to the ground. LAI has an impact on tree growth and recruitment through the interception of light, which in turn affects primary productivity. Even though many instruments exist for estimating LAI from ground, they are often laborious and costly to run continuously. Measurements of LAI from the field using traditional sensors (e.g., LAI-2000) require multiple visits to the field under very specific sky conditions, making them unsuitable to operate in inaccessible areas and forests with dense vegetation, as well as areas where persistent sunny conditions are the norm like tropical dry forests. With this context, we proposed a methodology to characterize light diffusion based on NDVI and LAI measurements taken from the field in two successional stages in the tropical dry forest of Santa Rosa National Park in Costa Rica. We estimate a "K" coefficient to characterize light diffusion by the canopy, based on field NDVI measurements derived from optical phenology instruments and MODIS NDVI. From the coefficients determined, we estimated LAI values and compared them with ground measurements of LAI. In both successional stages ground measurements of LAI had no significant difference to the tower-derived LAI and the estimated LAI from MODIS NDVI.

Leaf Area Index (LAI) has been defined as the total leaf area (one-sided) in relation to the ground. LAI has an impact on tree growth and recruitment through the interception of light, which in turn affects primary productivity. Even though many instruments exist for estimating LAI from ground, they are often laborious and costly to run continuously. Measurements of LAI from the field using traditional sensors (e.g., LAI-2000) require multiple visits to the field under very specific sky conditions, making them unsuitable to operate in inaccessible areas and forests with dense vegetation, as well as areas where persistent sunny conditions are the norm like tropical dry forests. With this context, we proposed a methodology to characterize light diffusion based on NDVI and LAI measurements taken from the field in two successional stages in the tropical dry forest of Santa Rosa National Park in Costa Rica. We estimate a "K" coefficient to characterize light diffusion by the canopy, based on field NDVI measurements derived from optical phenology instruments and MODIS NDVI. From the coefficients determined, we estimated LAI values and compared them with ground measurements of LAI. In both successional stages ground measurements of LAI had no significant difference to the tower-derived LAI and the estimated LAI from MODIS NDVI.

SUMMARYAmong the most endangered tropical ecosystems, tropical dry forests are threatened by degradation that includes edge effects arising from perturbations such as the creation and maintenance of roads and other clearings. While much is known about these adverse effects on tree communities in tropical moist forests, similar effects in tropical dry forests are little understood. This paper examines the relationship between roads, road-related exotic plant invasion and tree community change in a tropical dry forest in southern India. Forty pairs of roadside and interior plots across four factorial combinations of road width (wide and narrow) and understorey type (native and exotic) were sampled. Tree death and extant tree community composition were compared using generalized linear models and similarity analyses. Tree death near roads was more than double that away from them, suggesting that roads may increase tree death in these forests. The interactive effect of understorey type (exotic or native) and road width on tree death was significant, with highest tree death near wide roads bordered by exotic understorey. Conversely, tree community composition was influenced by road width and understorey type, but not by proximity to roads. Creation and maintenance of roads for forest management may have serious implications for tree communities in tropical dry forests and should thus be minimized. Exotic plants may also be important contributors to increasing tree death, and further research on their impacts, particularly into underlying mechanisms, is critical to the long-term conservation of tropical dry forest communities.

Understanding how structure and function change across environmental gradients is a fundamental goal of ecology, with important applications in a changing world. In this dissertation, I explore how environmental variations in temperature and precipitation affect three-dimensional canopy structure, and how this, in turn, affects forest function. Characterising how climatic variations affect forest structure and function is particularly important in tropical forests, which are globally important carbon stores that have already shown vulnerability to climate change. The future of tropical forest carbon stocks is highly uncertain, with plant physiological responses representing the largest source of model uncertainties. As such, my dissertation research comprises empirical investigations into how tropical forests will respond to high temperatures and drought. Firstly, I examine tropical forest response to high temperature by conducting a comparison of natural forest sites and a tropical forest mesocosm using eddy-covariance data. I present evidence that high temperature declines in tropical forest photosynthesis are not due to direct temperature effects (i.e., that cause damage to the photosynthetic machinery), but instead are predominantly due to indirect temperature effects that result from concurrent increases in vapour pressure deficit (VPD). While both mechanisms reduce photosynthesis, the impact of increased VPD under future climate may be partly mitigated by enhanced water-use efficiency associated with rising atmospheric CO2 concentrations, suggesting that tropical forests may have opportunities for resilience in the face of global warming. The second part of my dissertation research examines how tropical forest canopy structure responds to seasonal dry periods and anomalous droughts on seasonal and interannual timescales, using data from ground-based LiDAR (Light Detection and Ranging). I show that total leaf area index (LAI) does not represent the seasonality of forest structure, since the upper and lower canopy levels exhibit divergent seasonal responses. The seasonal pattern of upper canopy LAI shows good agreement with the seasonal pattern of enhanced vegetation index (EVI) measured from satellites, suggesting that satellites are not capturing the response of the lower canopy. These results indicate that smaller trees are responding to seasonal water limitations and larger trees to light availability. I found that the response of canopy structure to anomalous (El Niño-induced) drought was similar to seasonal dry periods, but that the trends in LAI and vertical canopy structure were amplified. In particular, I document a delayed loss of LAI from the upper canopy following extreme drought, which supports the idea that while smaller trees may be more responsive to shorter, less severe dry periods, larger trees are more susceptible to prolonged or more severe droughts. Finally, I combine a long-term ground-based LiDAR dataset with tree inventory data in order to identify the mechanisms (i.e., changes in leaf area and/or woody biomass) of structural changes caused by droughts. I present evidence that loss of lower canopy LAI following an El Niño-induced drought was due to the mortality of small trees, not loss of leaf area, while an increase in LAI in the upper canopy predominantly resulted from plastic leaf area changes. If small trees are susceptible to drought-induced mortality and the incidence of droughts increases, this could prevent the recovery of tropical forests from drought-induced disturbances.

La riqueza de orquídeas en Colombia alcanza una cifra de 4.270 especies, sin embargo, nuevos hallazgos sugieren no haber llegado a un punto de inflexión. La condición epífita en el 69% de sus especies y su ubicación en el dosel, desfavorece su colección y registro, más aún, en ecosistemas fragmentados como el Bosque seco Tropical (Bs-T). Este ecosistema en Colombia, ocupó 9 millones de hectáreas y actualmente solo se mantienen 720.000 has, sin embargo, ha sido insuficientemente explorado y la flora epífita presenta grandes vacíos geográficos. La fertilidad del suelo y el relieve llano, facilitó el establecimiento de ciudades, el desarrollo de la agricultura, la ganadería, pero también aceleró la pérdida de especies vegetales. En los últimos 400 años la introducción de ganado bovino en la región del Caribe y Magdalena y 130 años, el cultivo de la caña de azúcar en el Valle del río Cauca, han sido las principales causas de la transformación. En este sentido, las orquídeas del Bs-T es el foco de atención de esta tesis, mejorar el conocimiento de su pasado, explorar su presente y planificar su futuro han sido abordadas empleando diferentes metodologías a escala regional y nacional. Una primera línea amplio el conocimiento de las orquídeas del Valle geográfico del río Cauca, (694.760 hectáreas y 2% de coberturas Bs-T) en un 112% y se completó un catálogo con 71 especies para esta bioregión al sur-occidente de Colombia. Del total, 10 especies son endémicas, una es nueva para la ciencia y 38 no se conocían en estudios previos. Se detectó afinidades florísticas con las tres unidades fisiográficos características, ocho de ellas son exclusivas de la Cordillera occidental, 15 de la Cordillera central, tres de la Llanura aluvial, en tanto que 25 especies son compartidas por las tres unidades fisiográficas. Se detectó un decrecimiento en la riqueza de especies en sentido norte-sur que guarda relación con el uso del suelo. Los resultados de presencia, evidencian la extinción local de 19 especies durante el último siglo, sugiriendo que el cultivo industrial de caña de azúcar, es el máximo responsable de la pérdida de biodiversidad. Una segunda línea se empleó un grupo de siete especies de orquídeas epífitas típicas del Bs-T de la región del Valle del río Cauca y Dagua para detectar los cambios en la distribución espacial y planificar su conservación frente al cambio climático (CC). El modelamiento fue realizado con Maxent con el escenario SRES-A2 de CC para el horizonte temporal (2080-2100). Los resultados muestran un incremento altitudinal para el escenario de CC y un incremento en la idoneidad en áreas de montaña media en detrimento de las áreas basales donde actualmente se encuentran las orquídeas. La concentración de áreas idóneas fue mayor en la cordillera occidental que en la Cordillera central. Variables como la accesibilidad, el tipo de cobertura, la temperatura y la disponibilidad hídrica, explican el 88,6% del modelo. Se proponen el establecimiento de Corredores de Migración Altitudinal -CMA- como alternativa frente a una pérdida de biodiversidad en el Bs-T. Una última línea identifica en cinco bioregiones de Bs-T en Colombia, los cambios espacio- temporales de un grupo focal de 12 especies. Se empleó el algoritmo usado por MaxEnt y el escenario de emisiones SRES 8.5 para dos periodos: (2030) y (2050). Los resultados muestran un desplazamiento altitudinal respecto al presente condicionado por variables como: temperatura, accesibilidad, y la precipitación. Las áreas de montaña media, incrementarán su idoneidad en detrimento de las tierras bajas. Los umbrales de polinizadores (euglossini), disponibilidad de forófitos, distancias a coberturas de Bs-T y áreas protegidas, sugieren mejorar la conectividad entre tierras bajas y zonas de montaña media. Se presentan 69 nichos climáticos como estrategia de conservación frente al cambio climático.
Orchid diversity in Colombia reaches 4,270 species; new discoveries, however, suggest that an asymptote has not yet been reached. The epiphytic condition in 69% of orchid species and their location in the canopy makes it difficult to collect and register them, even more so in fragmented ecosystems such as Tropical Dry Forest. This ecosystem in Colombia occupied 9 million ha, of which at present only 720,000 ha remain. Nevertheless, this ecosystem has been insufficiently explored, and there are large geographic gaps in our knowledge of the epiphytic flora. In the last 400 years, the introduction of cattle in the Caribbean and Magdalena regions, and in the last 130 years, the cultivation of sugar cane in the Cauca Valley, have been the main causes of this transformation and accelerated the loss of plant species. In this sense, the orchids of the Tropical Dry Forest are the focus of attention of this thesis, in order to improve knowledge of their past, explore their present, and plan their future, using different methods at regional and national scales. A first line of research augmented knowledge of the orchids of the geographic Cauca Valley (694,760 ha and 2% of coverage by Tropical Dry forest) by 112% and completed a catalogue with 71 species for this bioregion of southwestern Colombia. Of the total, 9 species are endemic, one is new to science, and 38 were not known in previous studies. A second line of research used a group of seven typical epiphytic species of orchids of Tropical Dry Forest of the Cauca and Dagua river valleys to detect changes in spatial distribution and plan their conservation with respect to climate change. Modeling was carried out with MaxEnt, with the scenario SRES-A2 of climate change for the time horizon 2080-2100. The results show an altitudinal increase for the climate change scenario and an increase in suitability in mid-mountain areas, with a decrease in suitability of basal areas, where orchids are found at present. The concentration of suitable areas was greater in the Western Cordillera than in the Central Cordillera. Variables such as accessibility, type of coverage, temperature, and water availability explain 88.6% of the model. The establishment of Altitudinal Migration Corridors is proposed as an alternative for dealing with biodiversity loss in Tropical Dry forest. A final line of research identifies spatial-temporal losses of a focus group of 12 species in five bioregions of Tropical Dry Forest in Colombia. The algorithm of MaxEnt was used, with a scenario of emissions SRES 8.5 for two periods, 2030 and 2050. The results show an altitudinal displacement relative to the present, conditioned by variables such as temperature, accessibility, and precipitation. Mid-mountain areas will increase their suitability, and lowlands will decrease in suitability. The thresholds for pollinators (Euglossini), availability of tree hosts, and distances to coverage of Tropical Dry Forest and protected areas suggest that connectivity between lowlands and mid-mountain zones should be improved. Sixty-nine climatic niches are presented for Colombia as a conservation strategy for adapting to climate change.

Forest and product certification was initially promoted as a means of enhancing sustainable management of forests in the tropics. However after almost two decades, there is still very little evidence of certified timber products originating from tropical countries. A number of approaches have been suggested to enhance the growth of forest certification in the tropics. These approaches such as that of the Forest Stewardship Council, Global Forest Trade Network of the World Wide Fund for Nature (WWF), Sustainable Forest Initiative and various private sector initiatives have all failed to facilitate forest certification. Therefore to enhance the development of forest certification in Ghana, the research work amongst others, draws on experiences in certification from other sectors such as cocoa, fisheries, tourism and oil palm to develop a model for promoting forest certification in Ghana. The research work uses elements identified in the literature review in developing a questionnaire for the survey of timber firms in Ghana. The research work identified stakeholder consultations, legal framework, resource rights, and the regulation of the domestic market as key elements for promoting forest certification in Ghana. The research recommends a phased approach to promoting forest certification with the first phase being verification of legality that adopts the European Union Forest Law Enforcement, Governance and Trade (FLEGT) and the Voluntary Partnership Agreement (VPA) initiative. The study identifies this approach not only as a means of reducing cost to the private sector in pursuing forest certification but a means of drawing on support measures to enhance the regulation of the domestic market; a key component for promoting forest certification. The report argues that it is only through a well regulated domestic market can tropical timber producing countries achieve sustainable forest management and hence forest certification. The domestic market is therefore seen as a strong means of promoting certification since it will be internalised in the producing countries. None of the research on certification has so far identified the domestic market as a key factor to promoting forest certification and the research work argues that the slow pace of certification has been the lack of demand for certified products on the domestic market. Developing the domestic market is therefore seen as a key policy instrument for promoting the uptake of forest certification in Ghana and the tropics in general.

This thesis analyzed the dynamics of tree radial growth at different time-scales in relation to climate and drought in two tropical dry forests (TDFs) from Colombia (Tuluá) and Bolivia (INPA). The specific objectives were: (i) To assess intra-annual patterns of radial growth (radial- increment dynamics and xylogenesis) in ten coexisting tree species from Tuluá and INPA and determine their relationship with climate and leaf phenology. (ii) To analyze the effects of climate and drought on long-term radial growth at different time-scales using dendrochronology in seven coexisting deciduous tree species from INPA. (iii) To evaluate the long-term radial growth responses to changes in climate water balance and determine their relationship with sapwood density in seven coexisting deciduous tree species from INPA. At intra-annual scales it was found that: (i) cambium reactivation and xylem growth of tree species occurred during the wet season, reflecting the influence of high precipitation and a positive water balance on the development of new xylem cells. (ii) In the semi-deciduous tree species from Tuluá the xylem growth period overlapped with the wet season, whereas, in the deciduous tree species from INPA, the growth period started at the mid wet season, when the tree crowns were fully developed. (iii) Temperature, as a determinant factor in the hourly fluctuations of both the vapor pressure deficit (VPD) and the evapotranspiration rate, could exert a huge influence on tree radial growth dynamics during the growing season. In Tuluá, the growing season was particularly associated with low temperatures and hence low VPD, while in INPA the growing season was related to high temperatures and VPD. Nevertheless, the high temperatures registered throughout the day at both TDFs negatively affected radial increment at hourly scales. Tree species could face the adverse dry conditions by restricting growth to periods of the day when temperatures are low. (iv) Stem shrinkage and swelling occurred at hourly to daily scales in all tree species, and most INPA tree species registered strong reversible shrinkage at monthly scales. Particularly, the climate controls on radial-increment dynamics varied between daily and monthly scales. At daily scales, there was a positive effect of high precipitation and positive water balance and a negative effect of VPD on the increment phase, while at monthly scales the precipitation was the main variable affecting radial increment positively. At inter-annual scales it was found that: (i) The tree radial growth showed a positive relationship with precipitation and climate water balance and a negative association with temperature, indicating that the tree species studied share high common growth variability in response to local climate. Nevertheless, the strongest response of growth to climate was species-specific, indicating that there was a differential sensitivity among tree species to these climate variables. (ii) The radial growth of all tree species responded positively to water balance during the wet season, but such responses differed among species as a function of their stem sapwood density. Specifically, sapwood density was negatively related to growth variability explained by water balance. Tree species with low-density wood and high production of sapwood were the most sensitive to water balance, whereas species with the opposite characteristics were the least sensitive ones. (iii) Tree species tolerated short-term droughts while they were particularly sensitive to long-lasting droughts. This indicates that tree species from the INPA site are predominantly sensitive in terms of growth reduction to long-lasting droughts. The most temperature-sensitive tree species, also showed the highest growth sensitivity to long-lasting droughts. In contrast, growth of the tree species with the lowest sensitivity to water balance, did not respond to long-term drought variability.
Esta tesis evaluó la dinámica del crecimiento radial a diferentes escalas temporales y determinó su relación con el clima y la sequía en dos bosques secos tropicales de Colombia (Tuluá) y Bolivia (INPA). A escalas intra-anuales se encontró que: (i) la reactivación del cambium y el crecimiento del xilema ocurre durante la época húmeda del año en ambos bosques. Esto refleja la influencia de las altas precipitaciones y los valores positivos del balance hídrico atmosférico en el desarrollo de las nuevas células del xilema. (ii) El período de crecimiento en Tuluá estuvo asociado a temperaturas bajas y, por ende, a un déficit de presión del vapor (DPV) bajo, mientras que en INPA la estación de crecimiento estuvo asociada a valores altos de temperatura y DPV. Sin embargo, en ambos sitios de estudio, las temperaturas altas registradas a lo largo del día afectaron negativamente el incremento radial a escalas horarias. Las especies pueden hacer frente a estas condiciones adversas, por ejemplo, restringiendo el crecimiento a períodos del día que registren temperaturas bajas, ya que la pérdida de agua asociada a la evapotranspiración también sería baja. A escalas inter-anuales se determinó que: (i) el crecimiento radial de todas las especies de INPA presentó una asociación positiva con la precipitación y el balance hídrico atmosférico y una relación negativa con la temperatura. Esto indica que todas las especies comparten una señal común de la variabilidad del crecimiento en respuesta al clima local. No obstante, la fuerza de la respuesta fue especie-específica. Esto indica que existe una sensibilidad diferencial entre las especies al clima. (ii) El crecimiento radial de todas las especies de INPA respondió positivamente al balance hídrico atmosférico durante la estación húmeda, pero esa respuesta fue diferente entre las especies en función de la densidad de la albura. La densidad de la albura fue negativamente relacionada a la variabilidad del crecimiento explicada por el balance hídrico. (iv) Las especies de INPA fueron resilientes a las sequías de corto plazo (estación seca anual), mientras que el crecimiento fue particularmente sensible a las sequías de larga duración (sequías multi-anuales), excepto en las especies con alta densidad de la albura.

Comment le droit international peut-il règlementer des phénomènes complexes ? Cette question se pose avec une acuité particulière en ce qui concerne la déforestation tropicale. En effet, les difficultés techniques et les intérêts divergents des États, découlant de l’interaction des multiples services assurés par les forêts, ont empêché l’adoption d’une convention internationale en ce domaine. Néanmoins, les négociations menées au sein du régime international du climat ont créé un mécanisme dit de « réduction des émissions résultant du déboisement et de la dégradation des forêts et le rôle de la conservation et de la gestion durable des forêts et du renforcement des stocks de carbone forestiers dans les pays en développement » (REDD+). Défini par un ensemble de décisions de la Conférence des parties à la convention-cadre des Nations-Unies sur les changements climatiques, il a déjà permis d’initier, sur le territoire des pays en développement, une amélioration substantielle du contrôle des ressources forestières et des réformes règlementaires et institutionnelles de grande ampleur. Notre étude se propose d’évaluer les spécificités du système normatif mis en place sur la REDD+. Elle a pour objet, en dépassant l’apparente faiblesse formelle des instruments juridiques sur lesquels il repose, de mettre en évidence sa portée normative. Elle révèle l’aptitude du droit international à règlementer des phénomènes complexes en donnant naissance à des systèmes juridiques adaptatifs. Elle démontre que la spécificité de tels systèmes normatifs réside dans la satisfaction de deux exigences opposées : la flexibilité et la sécurité juridique
How International law can regulate complex phenomenon? This question appears particularly relevant if we consider tropical deforestation. Technical issues and the opposite interests of States, stemming from interlinked services provided by forest, had prevented International community to adopt a convention on forests. Nevertheless, climate regime has recently created a so-called mechanism on « reducing emissions from deforestation and forest degradation in developing countries and the role of conservation and sustainable management of forests and enhancement of forest carbon stocks in developing countries » (REDD+). The normative framework laid down in decisions of the Conference of the parties has stimulated control improvement on forest resources and wide-ranging reform in developing countries. The study will evaluate the specificities of this normative system by going further its apparent normative weakness. It will expose how International law manage to regulate complex phenomenon by producing adaptive legal system. The study will demonstrate that the specific feature of this system lies in its ability to conciliate two opposite needs: flexibility and legal security

There has been a rapid change in forest and land cover globally, especially in tropical forests due to heavy deforestation. The highest rate of deforestation is found predominantly in the developing world. Tropical deforestation is a process of transforming forests into cleared land for other uses. Tropical deforestation is the second largest source of greenhouse gas emissions, responsible for about 17 - 30% of global emissions of CO₂ to the atmosphere, causing global warming. Precise and up to date information on the distribution and rate of forest cover change, especially in tropical regions, is required urgently for government policies aiming to control and manage forests and land development. Information on deforestation in tropical regions has been unavailable or inconsistent, including in the Lao PDR, due to socio-economic deficits, political interests and geographical constraints. Remote sensing technology has played a crucial role in providing the information required for reliable mapping and monitoring of forest cover changes at local, regional and global levels, but its application in tropical regions has been lagging. The overall goal of this research was to demonstrate and evaluate remote sensing methods for assessing and monitoring forest cover changes in tropical environments, particularly in the context of the Lao People’s Democratic Republic (PDR). The first aim of the research was to understand phenology of tropical forests and related vegetation types, which has been little studied. Improved understanding of the phenology of tropical forests and other land covers involved in forest clearance and land use change is an important step towards the use of remote sensing to identify and track changes in forest cover. Long-term averages of land surface temperature (LST) and enhanced vegetation index (EVI) 16-day time series of MODIS over the seven-year period from 2006 to 2012 were calculated and their monthly transitions compared for forests, and for land covers that commonly replace forests. The findings showed the complex interrelationship of LST and EVI and their monthly transitions for the different land covers: they each showed distinctly different intra-annual LST and EVI variations. Secondly, the research evaluated whether the combined use of these indices (LST and EVI) can classify these land covers. It was found that there was high overall accuracy of separation of land covers by long-term means of these indices (86%). This knowledge can be potentially useful for further broadscale mapping of land cover and detection of deforestation in tropical forests. For the third objective, the use of remote sensing time series data for detecting spatial and temporal changes in forest cover in tropical environments was tested. The disturbance index (DI) model was applied to detect spatial changes in different forest cover types, whilst the Breaks For Additive Season and Trend (BFAST) approach was used to examine temporal changes in these land covers. Results showed that the DI was capable of detecting vegetation changes during a seven-year period with high overall accuracy (82%); however, it showed low accuracy in detecting forest clearance (42%). The BFAST analysis detected abrupt temporal changes in vegetation in the tropical forests, especially in large conversions of mixed wooded/cleared area into plantation (from 2004 to 2007). From these two approaches, it was found that MODIS time series data may be suitable for continental and national monitoring of land cover, although it may not provide the level of geographic detail and accuracy required for local assessments. As a result of these findings, further analysis of forest cover changes at a finer resolution was required to improve monitoring approaches. Therefore, the fourth aim was to detect and map vegetation cover changes at a higher spatial resolution over a period of ten years between 2003 and 2012. Landsat ETM+ imagery from 2003 and 2012 was used in principal component analysis (PCA). This technique detected areas of vegetation cover change (both vegetation increase and loss) with high overall accuracy (87%). The results of these four studies provided new information on where and when recent forest cover changes have occurred in southern Lao PDR. The final step was to analyse the reasons underlying these changes. Thus, the final research task was to investigate potential factors associated with forest cover change in the study area, by using logistic regression analysis. The results of the analysis suggested that particular socio-economic and physical factors have a significant association with forest cover change. Forest clearance was associated strongly with elevation, distance to main roads and shifting cultivation practices. Meanwhile, vegetation increase was more likely to correlate with rubber plantations. Native forest and shifting cultivation lands were vulnerable to being converted into rubber plantations. This final research component contributes to a better understanding of ongoing land cover change processes to inform land use management. This is key information for policy and decision makers, and may be used to minimize deforestation and deal with potential risks associated with land cover changes.
Thesis (Ph.D.) (Research by Publication) -- University of Adelaide, School of Biological Sciences, 2016.

Agroforests are model systems for ecological conservation in tropical agricultural landscapes because they integrate biodiversity conservation and rural livelihoods. Whether agroforests are long-term solutions for conserving biodiversity in agricultural landscapes may depend sapling regeneration of native forest trees in agroforests. In this dissertation, I ask two main questions: are native forest trees regenerating in agroforests and if so, what are the ecological and social drivers? I tested the influence of potential seed sources from both the landscape and parent trees found in the agroforest. I also examined how a set of social factors affected native forest tree regeneration. The social drivers I tested include tree management and use, land tenure and state-restricted rights to harvest native timber. I found that a number of native pioneer species are regenerating at relatively high frequencies and abundances. I also found that many secondary native forest tree species are also regenerating although their sapling are found less frequently and at lower abundances. Most primary forest tree species present as adults are not regenerating and lacked sapling in the agroforests. The influence of the ecological factors was limited. The main drivers of native forest tree regeneration on farms are the understorey management and the rural extension services that assisted farms obtain state-restricted rights.

Southeast Asia is not a natural biogeographical unit: it extends well north out of the tropics in Myanmar, while the eastern boundary bisects the island of New Guinea. It is also divided in two by one of the sharpest zoogeographical boundaries in the world, Wallace’s line (Figure 7.1; Whitmore 1987). There is, however, one important unifying feature that distinguishes it from most other regions of the tropics: Southeast Asia is a region of forest climates. Only on the highest mountains in Papua and northern Myanmar is the climate too cold for forest and, with the possible exception of some small rain-shadow areas, it is nowhere too dry. Elsewhere the only permanent non-forest vegetation in the region before the human impacts of the last few millennia was on coastal cliffs and beaches, seasonally flooded river plains, active volcanoes, and perhaps some small inland areas on soils too poor to support forest. Today, however, as a result of human impacts, forest occupies less than half of the region, with various anthropogenic vegetation types occupying the rest. The recognition of Southeast Asia, as defined here, as a separate political and geographic entity is very recent, so it is not surprising that there has been no previous account of the vegetation of the whole region. Van Steenis (1957) gave a general account of the vegetation of Indonesia, while Whitmore (1984) concentrated on the tropical evergreen forests of the region, with only a brief description of the vegetation of drier climates. Champion (1936) described the principal forest types of Myanmar, while Vidal (1997) covered the vegetation of Thailand, Cambodia, and Lao PDR. Numerous other publications describe smaller areas or specific vegetation types. To a first approximation, the potential natural vegetation of the region (Plate 1) up to about 20°N is controlled by two main environmental gradients: a horizontal gradient of water availability and a vertical, altitudinal gradient. Water availability is determined largely by the amount and distribution of rainfall, with the length of the dry season the most important factor, although the water storage capacity of the soil becomes increasingly significant at the drier end of the gradient.

East and South-East Asia is a vast and diverse region (Fig. 6.1). The northern boundary can be taken as approximately 45 degrees latitude, from the Gobi desert on the west across Manchuria to the northern shores of Hokkaido, the main island of northern Japan. The southern boundary is over 6,000 kilometres away: the chain of islands from Java to New Guinea, approximately 10 degrees south of the Equator. From west to east across South-East Asia, from the western tip of Sumatra at 95 degrees longitude to the eastern end of New Guinea at 150 degrees longitude, is also some 6,000 kilometres. Transitions to farming within this huge area are discussed in this chapter in the context of four major sub-regions: China; the Korean peninsula and Japan; mainland South-East Asia (Vietnam, Laos, Cambodia, Thailand, the Malay peninsula); and island South-East Asia (principally Taiwan, the Philippines, Sumatra, Java, Borneo, Sulawesi, and New Guinea). The chapter also discusses the development of agricultural systems across the Pacific islands to the east, both in island Melanesia (the Bismarck Archipelago and the Solomon Islands east of New Guinea) and in what Pacific archaeologists are terming ‘Remote Oceania’, the islands dotted across the central Pacific as far as Hawaii 6,000 kilometres east of Taiwan and Easter Island some 9,000 kilometres east of New Guinea—a region as big as East Asia and South-East Asia put together. The phytogeographic zones of China reflect the gradual transition from boreal to temperate to tropical conditions, as temperatures and rainfall increase moving southwards (Shi et al., 1993; Fig. 6.2 upper map): coniferous forest in the far north; mixed coniferous and deciduous forest in north-east China (Manchuria) extending into Korea; temperate deciduous and broadleaved forest in the middle and lower valley of the Huanghe (or Yellow) River and the Huai River to the south; sub-tropical evergreen broad-leaved forest in the middle and lower valley of the Yangzi (Yangtze) River; and tropical monsoonal rainforest on the southern coasts, which then extends southwards across mainland and island South-East Asia. Climate and vegetation also differ with altitude and distance from the coast.

In 1999 the Earth’s atmosphere was gearing up for a special event. Towards the end of July, the 500 mb flow in the extra-tropical SH started to look more and more like a flow pattern observed some 22 years earlier in May 1977. Two trajectories in the N-dimensional phase space, N as defined in Chapter 6, were coming closer together. Figure 7.1 shows the two states at the moment of closest encounter, with the appropriate climatology subtracted. These two states are, for a domain of this size, the most similar looking patterns in recorded history. But are these good analogues? They do look alike, nearly every anomaly center has its counterpart, but they are certainly not close enough to be indistinguishable within observational error, the anomaly correlation being only 0.81. The rms difference between the two states in Figure 7.1 is 71.6 gpm, far above observational error (<10 gpm). The close encounter did not make it to the newspapers and, more telling, not even to a meteorological journal. The idea of situations in geophysical flow that are analogues to each other has always had tremendous appeal, at least in meteorology. Even lay people may comment that the weather today or this season reminds them of the weather in some year past. The implications of true analogues would be enormous. If two states many years apart were nearly identical in all variables on the whole domain (of presumed relevance) , including boundary conditions, then their subsequent behavior should be similar for some time to come. In fact one could make forecasts that way, if only it was easy to find analogues from a “large enough” data set. The analogue method was fairly widely used for weather forecasting at one time (Schuurmans 1973) but currently is rarely used for forecasts per sé (for all the reasons explained in Section 7.1). Rather analogues are used to specify one field given another, a process called “specification” or downscaling, or to learn about predictability (Lorenz 1969). In Section 7.1 we review the idea and limitations of naturally occurring analogues, and explain why/when it is (un)likely to find analogues.

El Centro Climático del Caribe del USDA, en colaboración con GreenWood Inc., realizó un foro en el Instituto Internacional de Dasonomía Tropical del Servicio Forestal el 10 de abril del 2018 donde reunieron a más de 60 personas. El objetivo de este foro fue abrir un diálogo sobre la recuperación de madera, su procesamiento y la comercialización de productos maderables en Puerto Rico para el aprovechamiento de troncos y ramas de árboles caídos por los huracanes Irma y María. El foro estuvo dirigido a aserradores, artesanos, ebanistas, arquitectos y personas que trabajan con madera o con la venta de productos maderables. Debido al valor económico y cultural de las especies maderables tropicales, se pueden crear actividades económicas a partir de los desechos vegetales que se generan luego de los huracanes. Millones de ramas y árboles caídos se pueden procesar para producir composta, mulch, madera para carbón y biocombustibles, o materia prima para artesanos y para construcción. También hay valor económico en el manejo de materiales leñosos, la venta de herramientas y equipos para mover y procesar materiales leñosos, y en la venta de productos de madera de valor agregado. Además, muchos productos de madera almacenan carbono indefinidamente y mitigan los aumentos de CO₂ en la atmósfera.

Este análisis demuestra que la gran mayoría de los países con bosques tropicales que pretenden beneficiarse de los mercados internacionales de carbono forestal aún no han definido en la ley y en la práctica los derechos de los Pueblos Indígenas, comunidades locales y Pueblos Afrodescendientes sobre el carbono en sus tierras y territorios consuetudinarios.

Estamos ante una encrucijada global de proporciones nunca vistas. El planeta se calienta más rápido de lo esperado y enfrentamos condiciones climáticas cada vez más extremas, lo que pone en riesgo la sostenibilidad de la vida humana en el mediano y largo plazo. El nivel de los océanos está aumentando, los arrecifes de coral están muriendo, las especies se están extinguiendo, los glaciares se están derritiendo y las condiciones climáticas extremas se hacen cada vez más frecuentes con intensas olas de calor, inundaciones, huracanes, incendios y/o sequías. Para hacer frente a esta compleja situación, todos, personas e instituciones en los ámbitos nacional, regional y global, tenemos que hacer nuestra parte para evitar llegar a un punto de no retorno. Aunque Colombia solo genera el 0,6 % de los gases de efecto invernadero (GEI), es uno de los veinte países más amenazados por la crisis climática. Nuestro país alberga el 50 % de los páramos del mundo y es catalogado como una potencia en agua, biodiversidad y ambiente, aloja alrededor del 10 % de la fauna y flora del mundo, teniendo por ello un rol central en los esfuerzos globales que se realizan para mitigar los efectos del cambio climático. También es reconocido por ser el segundo país con más alta presencia en biodiversidad en la tierra, goza de dos océanos, cinco vertientes hidrográficas, ríos, lagunas y ciénagas, siendo de esta manera el agua un recurso fundamental para el desarrollo de las generaciones futuras. El país cuenta con grandes extensiones de páramos, los cuales son la fuente del 70 % de agua dulce en nuestro país y comparte al sur de nuestras fronteras con la Amazonía, considerada la selva tropical más extensa del planeta y el pulmón del mundo. Una porción representativa de ese 10 % del total de la biodiversidad mundial que tiene nuestro país, se encuentra dentro del Sistema Nacional de Áreas Protegidas (SINAP), del que hace parte el Sistema de Parques Nacionales Naturales y las Reservas Forestales (más de 17 millones de hectáreas), una fuente importante de bienes y servicios ecosistémicos, entre los cuales, el suministro del recurso hídrico incluye más del 62 % de los nacimientos de los acuíferos nacionales y abastece a casi un 80 % de la población colombiana. Así mismo, protege lagunas y ciénagas que contienen el 20 % de los recursos hídricos que abastecen la generación de energía eléctrica del país. En estas áreas protegidas se conservan muestras representativas de los ecosistemas naturales marinos y continentales, los cuales, además de albergar un gran número de especies de fauna y flora, contribuyen a la regulación del clima y protegen las cuencas hidrográficas. Es así como por su especial importancia ecológica, los Parques Nacionales Naturales tienen la función de conservar, proteger y salvaguardar sus ecosistemas de especial valor por medio del Estado y de los particulares. Esta gran riqueza ambiental del país está siendo amenazada por el uso indebido de los recursos naturales, lo que genera un acelerado deterioro de los ecosistemas, alterando su funcionalidad y poniendo en riesgo la biodiversidad. Esta problemática se ha convertido en un reto de primer orden para el Estado colombiano, sus autoridades ambientales y la sociedad en general. El Sector Defensa no ha sido ajeno a esta realidad, por lo que en el marco definido por la ley, la Presidencia de la República y el Ministerio de Ambiente y Desarrollo Sostenible, ha reconocido el potencial desestabilizador de las afectaciones causadas por las diversas actividades ilícitas de los Grupos Armados Organizados (GAO), los Grupos Delincuenciales Organizados (GDO) y ciudadanos que hacen un uso indebido de los recursos naturales. Fenómenos como la siembra de cultivos ilícitos, la extracción ilícita de minerales, la tala indiscriminada, la ganadería extensiva, el acaparamiento de tierras, la pesca ilegal, la contaminación, el vertimiento de sustancias peligrosas y el tráfico ilegal de flora y fauna, han debilitado los ecosistemas nacionales. Estas actividades ilegales afectan los recursos hídricos del país, los suelos, los páramos y la atmósfera, produciendo efectos negativos que generan deforestación, pérdida de hábitats, extinción de especies, la destrucción de fuentes de agua, el deterioro de las tierras de cultivos e impactos negativos en las reservas forestales y las áreas que integran el Sistema Nacional de Áreas Protegidas (SINAP). La degradación ambiental que hemos visto no solo es utilizada por las organizaciones criminales para obtener recursos que les permiten sostener su accionar delictivo en diversas zonas del país, más grave aún, se constituye en un atentado directo contra el porvenir de las generaciones futuras. Es por ello que el Sector Defensa ha reconocido el agua, la biodiversidad y el medio ambiente como activos estratégicos de interés nacional, con un carácter principal y prevalente, buscando apoyar con sus capacidades a las autoridades ambientales del país, con el fin de realizar acciones cada vez más eficaces contra las organizaciones criminales responsables del deterioro ambiental. Es en ese contexto surge la idea de este libro, que busca presentar la problemática que se enfrenta y visibilizar las acciones realizadas por el Sector Defensa en coordinación con las autoridades ambientales, con el fin de apoyar la defensa de estos activos estratégicos, así como prevenir los daños futuros a los mismos, en aras de trabajar en la protección de los recursos naturales, bajo una visión multidimensional de la seguridad. El Ministerio de Defensa (MDN) ha sido consciente de los desafíos climáticos a los que se enfrenta, no solo el Sector, sino el territorio nacional, en cuanto a los impactos cada vez mayores derivados de las condiciones meteorológicas extremas y la explotación de los recursos. Por ello, el Sector ha trabajado para alinearse con la Política Nacional de Cambio Climático, los compromisos del país ante la Contribución Nacionalmente Determinada (NDC), el cumplimiento del CONPES 4021 de diciembre de 2020 para el Control de la Deforestación y la Gestión Sostenible de Bosques, para así aportar con acciones de adaptación, mitigación y gestión del riesgo ante el cambio climático y variabilidad climática mediante del Plan de Gestión de Cambio Climático del Sector Defensa (PIGCCSD). Este libro reúne los principales resultados del Sector Defensa en materia de protección del medio ambiente y resalta la articulación de las políticas, así como de la operativización de las mismas por parte de las Fuerzas Militares y la Policía Nacional, por la protección de los recursos naturales de la Nación, una responsabilidad que ha quedado claramente plasmada en la “Estrategia Artemisa”, que es un esfuerzo permanente, sostenido, conjunto, coordinado, e interinstitucional que permitirá proteger y defender el agua, la biodiversidad y el medio ambiente como activos estratégicos de la Nación, a partir de la lucha contra la deforestación, sus causas directas o subyacentes y contrarrestar los efectos del cambio climático, como también la lucha contra la explotación ilícita de minerales, contra los cultivos ilícitos que afectan el medio ambiente y el conjunto de actividades de control y vigilancia que apoya nuestra Fuerza Pública para la defensa de los recursos naturales. Trabajando de forma articulada con la Fiscalía, el Ministerio de Medio Ambiente y Desarrollo Sostenible, el Instituto de Hidrología, Meteorología y Estudios Ambientales (Ideam), y la Unidad de Parques Nacionales Naturales, en diversas zonas del país, la Estrategia Artemisa ha permitido brindar apoyo a las autoridades ambientales y administrativas, para preservar y defender el agua, la biodiversidad y el medio ambiente en las áreas de reserva forestal, áreas protegidas y 59 Parques Nacionales Naturales. Mediante la Directiva Permanente 008 del 22 de marzo de 2022, el MDN institucionalizó e impartió lineamientos e instrucciones al Comando General de las Fueras Militares, la Dirección General de la Policía Nacional y la Unidad de Gestión General del MDN, con el propósito de implementar medidas, desplegar operaciones, actividades de apoyo y gestión ambiental, para la implementación de la Estrategia Artemisa. De esta forma y bajo un enfoque sostenido, conjunto, coordinado, interinstitucional y multilateral, se trabajará para incluir dentro de la doctrina militar y policial las acciones relacionadas con la protección del agua, la diversidad y el medio ambiente, al tiempo que se concentrarán los esfuerzos de inteligencia en la identificación del modus operandi de las organizaciones criminales que afectan el medio ambiente, desarrollando operaciones contra los GAO y los GDO que atentan contra el medio ambiente. Desde el 2019 a la fecha se han realizado diecisiete (17) operaciones sobre las áreas de los Parques Nacionales Naturales, especialmente en las regiones de la Amazonía y la Orinoquía, como son los Parques Nacionales Naturales (PNN) Serranía de Chiribiquete, PNN La Paya, PNN Tinigua, PNN Picachos, PNN Sierra de La Macarena, la Zona de Reserva Forestal de la Amazonía y la Reserva Natural Nukak. Se han dispuesto, para esta campaña, 22.300 hombres de la Fuerza Pública, que, desde sus respectivas unidades militares y policiales resguardan las áreas protegidas del territorio nacional. Estas unidades incluyen: 10 batallones de alta montaña (páramos), una brigada contra el narcotráfico, una brigada contra la minería ilegal, unidades de guardacostas, infantería de marina y efectivos de la Policía Nacional. El Sector Defensa es consciente de que a futuro será fundamental continuar fortaleciendo las capacidades de la Fuerza Pública para, en el marco de sus competencias, continuar apoyando a las autoridades ambientales, entes territoriales y a la comunidad en la defensa y preservación del agua, la biodiversidad y el medio ambiente como activos estratégicos de la Nación. Será fundamental profundizar la disrupción del delito de la explotación ilícita de minerales, mediante el desmantelamiento de las economías ilícitas que se lucran de ella y de la afectación de la cadena criminal. En igual medida, será vital apoyar la recuperación de los ecosistemas más afectados por las actividades ilegales, por medio de actividades de restauración de áreas, del trabajo articulado con las comunidades, la construcción y mantenimiento de viveros forestales y el fortalecimiento a las investigaciones científicas lideradas desde la Armada Nacional y la Dirección General Marítima para la protección de los océanos, el recurso hídrico y sus ecosistemas. De esta forma será posible continuar trabajando en la reducción de los riesgos que se ciernen sobre los ecosistemas del país y disminuir los índices de deforestación, y tras la búsqueda de soluciones que contribuyan a la reducción y mitigación de los GEI. Esta estrategia que ha puesto en marcha el Sector Defensa y que es recogido en esta obra, presenta los aportes sectoriales del trabajo interinstitucional que se han venido realizando en los últimos años, siendo un ejemplo de la forma en la que se pueden sumar esfuerzos para contribuir a la superación de la encrucijada global que nos afecta a todos y que debe ser enfrentada con un esfuerzo común.