Laboratory and greenhouse experiments were carried out with controlled burning and with seedling growth correlated to soil chemical changes. The surface of soil blocks from three sites of the Coastal Western Hemlock Zone were burned at two intensities and planted separately with seeds of Douglas-fir, western hemlock, and western redcedar. Growth data were recorded periodically and dry weights of the seedling crops were obtained to determine treatment differences. The burning procedure showed the insulating and cooling effects of the vaporizing soil moisture. The burning slightly increased germination of Douglas-fir and western hemlock, generally promoted fungal population, and initiated different chemical changes in the soil on each site. Dry matter production, for all species combined, varied with treatment for each site in the following decreasing order: Swordfern site - severely burned, moderately burned, unburned control; Moss site - unburned control, moderately burned, severely burned; Salal site - moderately burned, unburned control, severely burned. Comparisons of dry matter production on control blocks with that in nature indicated that the removal of blocks from the natural environment had significantly changed the original conditions. In consequence, new artificial sites were created. Consistent evidence of the rhizosphere effect was produced on soil pH by seedlings, especially by Douglas-fir. Dormancy was successfully broken in all plants and there was evidence of different responses in photo-periodism with each species. The highest dry matter production was directly related to increased soil pH, to increased partial cation saturation, and to increased concentration of available phosphorus but to a decreased cation exchange capacity. Cation exchange capacity was inversely related to the availability of nutrients. Decrease of cation exchange capacity proved to be a beneficial effect of fire. In this experiment, where the ash was not supplied as usual in a slash burn, the increased base saturation resulted from the decreased cation exchange capacity. As compared with field samples in August 1959, total nitrogen was lower in all blocks in June 1960. Nitrogen increased in the following year in all variants of the Swordfern site and somewhat in unburned control blocks of the Moss and Salal sites. The Swordfern site benefited from burning by accelerated mineralization, which substituted for the deprived seepage. Fire caused the least damage to this habitat. The Moss site suffered heavily by burning, which reduced humus, the main source of nutrition. The unburned blocks were benefited by fast decomposition of humus in the greenhouse. The Salal site's thick raw humus benefited from moderate burn, which removed part of the humus and acted as a fertilizer on the remainder. Severe burning was most harmful on this site by the destruction of the large part of humus. Rich soils, usually with seepage water, are less damaged by fire than poor soils with strong drainage. It is mainly because in rich soils organic matter is at least partly incorporated into the mineral horizon and acts readily after fire especially for nitrogen supply. / Science, Faculty of / Botany, Department of / Graduate

Through the use of standards the fire-control problem can be divided into its many phases, and specifications set for its solution. Fire-control standards fall into two classes, (1) the overall fire-control objective, and (2) standards to be met in attaining that objective. The former, or primary standards, serve to keep the various phases of fire-control at the most economically justifiable level. The latter, or secondary standards, ensure that all fire-control efforts conform with the primary standards. A full schedule of fire-control standards is presented. A system for assessing presuppression and suppression, first presented in 1932, was revised and elaborated for application as a current secondary standard. The principal feature of this system is that certain specifications must be met by the many phases of presuppression and prevention efforts before a numerical rating indicating adequacy is obtained. A different scale of rating should be set up for each fire-control unit, depending on the purposes of forest management and the nature of the fire hazard. Fire-control standards were analyzed from a theoretical point of view and a new primary standard, called the actuarial standard, was developed. Data from three Ranger Districts on Vancouver Island were studied through the actuarial assessment of past fire-control costs and damage, past fire danger, and expected trends. It was found that the actuarial standard was the only one of the three major standards that provided an adequate analysis of the fire-control problem on a given area and produced realistic results. A new secondary standard, called the local incentive standard is also presented. This standard relies on the value of enthusiasm and personal incentive in obtaining good results from fire-control employees. Dealing with burned area, this standard establishes the allowable annual burn by decreasing the past average burned area by 10 per cent each year. / Forestry, Faculty of / Graduate

Fire is a tool to reduce fuel and restore ecosystems but poses a risk of peat combustion that temporally restricts managers. Studies indicate that fires may be prescribed with a water table lower than the peat surface, but are based on locations with different peat properties or assumed heat inputs. The goal of this research is to quantify peat surface heating during a passing fire and the heat required to ignite peat under lowered water tables. This study used temperature probes at two heights to quantify peat surface heating during a prescribed fire and a manipulative experiment to quantify the effects of water table recession on peat properties important for predicting ignition. The soil surface experienced 87% of the flaming heat in sawgrass dominated areas. The heat required to ignite the peat surface was significantly correlated with the water table depth. This provides managers greater opportunity for prescribing fire. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection

This study investigated the potential regulatory effects of various coping strategies on Posttraumatic Stress Disorder (PTSD). It first divided PTSD symptoms and selected coping strategies into cognitive, social/motivational, and emotional types. The study then conceptualized each of the preceding types of coping strategies as being controlled stress responses and the PTSD symptoms as being semiautomatic stress responses. It lastly proposed that coping strategies be further divided into activating controlled stress response and deactivating controlled stress response. Controlled stress responses are coping strategies that are consciously initiated and implemented. Semiautomatic stress responses are PTSD symptoms that spontaneously emerge without conscious intent. Activating controlled stress responses consisted of the following coping strategies: seeking understanding, avoidant actions, and expressing feelings. Deactivating controlled stress responses encompassed: positive cognitive restructuring, emotion-focused support, and physical release of emotions. Semiautomatic stress responses entailed: reexperiencing, numbing, and arousal symptoms. It was proposed that cognitive, social/motivational, and emotional activating controlled stress responses would increase corresponding cognitive, social/motivational, and emotional semiautomatic stress responses. In the same vein, it was expected that cognitive, social/motivational, and emotional deactivating controlled stress responses would decrease respective semiautomatic stress responses. To illustrate, it was predicted that with regard to the cognitive regulatory system, its activating cognitive controlled stress response (seeking understanding) would exacerbate the frequency of associated cognitive semiautomatic stress responses (reexperiencing PTSD symptoms) whereas its deactivating cognitive controlled stress response (positive cognitive restructuring) would ameliorate it. Path analyses were conducted on correlation matrices whose elements represented two coping strategies (e.g., an activating controlled stress response: seeking understanding, and a deactivating controlled stress response: positive cognitive restructuring) and one PTSD symptom cluster of the same nature (e.g., the semiautomatic stress response: reexperiencing). Data were obtained from a sample of sixty-four children and adolescents ages 8-18. The coping strategies were assessed via ratings on items included in the How I Cope Under Pressure (HICUPS) instrument and the PTSD clusters through the use of the Diagnostic Interview for Children and Adolescents (DICA). Only one hypothesis was partially supported. It was found that the social/motivational activating controlled stress response (avoidant actions) indeed increased social/motivational semiautomatic stress responses (numbing symptoms). / Ph. D.

Recent advancements in the general child disaster literature underscore the important role of coping in children's postdisaster adjustment. Religious coping in children, a potentially important category of coping strategies, has received little attention until recent years. Moreover, its role in the context of post fire adjustment has not been studied. The present study examined the psychometric soundness of the Religious Coping Activities Scale (RCAS; Pargament et al., 1990) in children and adolescents and explored its utility in predicting children's religious coping over time: moreover, the study evaluated its role in predicting PTSD symptomatology over an extended period of time. This investigation included 140 children and adolescents (ages 8-18). Factor analyses of the RCAS revealed a 6-factor solution very similar to the factor structure in the original study. This finding suggests that the RCAS is a promising instrument to measure children's religious coping efforts. Hypotheses concerning the prediction of children's religious coping were only partially supported. Regression analyses indicated mixed findings in terms of the contributions of selected variables to the prediction of children's Spiritually Based Coping and Religious Discontent. Overall, the regression model predicted Religious Discontent better than Spiritually Based Coping. A mixed-effects regression model and hierarchical regression analyses were both employed to examine the role of children's religious coping in predicting short-term and long-term PTSD symptomatology following the residential fires. Results from the mixed-effects regression indicated that loss, time since the fire, child's age, race, and race by age interaction significantly predicted children's PTSD symptoms over time. However, time specific regression analyses revealed different predictive power of the variables across the three assessment waves. Specifically, analyses with Time 1 data revealed the same findings as did the mixed-effects model, except that time since the fire was not a significant predictor in this analysis. General coping strategies appeared to be the only salient predictors for PTSD at Time 2. Finally, Religious Discontent appeared to be negatively related to PTSD at a later time. / Ph. D.

For the purpose of fire analysis and fire safety engineering, the development of empirical correlations for major species yields in compartment fires has become an important priority due to the inability to calculate these quantities from first principles. Studies of simplified upper layer environments have shown that major species production rates can be correlated with the equivalence ratio in what is known as the Global Equivalence Ratio concept (GER). Due to the simplification in these past experiments, it was not known if the GER concept was valid for compartment fires. Therefore, there was a need to determine if correlations existed between major species yields and the equivalence ratio for actual compartment fires. Since the flow of toxic gases from a room poses a hazard to building occupants, it was also important to determine if correlations for CO yield outside of a compartment on fire exist, particularly when external burning occurs. A 2.2 m³ test compartment was used to investigate the burning of four fuels (hexane, PMMA, spruce and flexible polyurethane foam) in compartment fires. The test compartment was specially designed with a two-ventilation path system which allowed the direct measurement of the plume equivalence ratio (the ratio of the fuel volatilization rate to the air entrainment rate normalized by the stoichiometric fuel-to-air ratio). Empirical correlations between the upper layer yield of major species and the plume equivalence ratio were shown to exist The results reveal that the production of CO is primarily dependent on the compartment flow dynamics (i.e., the equivalence ratio) and upper layer temperature. A chemical kinetics study indicated that increased compartment temperature affects upper layer species yields in two ways 1) the generation of species in the plume is changed and 2} oxidation of post-flame gases in the layer is affected. The correlations developed in the compartment fifes were qualitatively similar to those developed by Beyler for simplified upper layer environments. However, quantitative differences existed and are explained by the temperature effect. The species yields downstream of hexane compartment flues were investigated and compared to upper layer yields. Results showed that downstream CO yields can be correlated to the plume equivalence ratio when taking into account the occurrence of external burning. When sustained external buning occurred for equivalence ratios greater than 1.7, downstream CO yields were reduced to 10 to 25 percent of the upper layer value. Results are very encouraging in indicating that an ignition criterion based on lean flammability limits is useful in predicting the flammability of upper layer gases in compartment fires. An ignition index value of 1.3 indicated the occurrence of sustained external burning and, thus, a reduction of CO, for the hexane fires studied. / Ph. D.

Thesis (Ph.D.)--Boston University / PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you. / This study is a quantitative analysis of the effect of fire and wind-throw on a spruce-fir-northern hardwoods forest on Peaks Island, Casco Bay, Maine. Six years after the burn, data for the effect of fire on approximately 170 acres of this forest type, were collected and categorized. The qualitative characteristics of the herb and shrub layers were noted and the soil analyzed. A random sample of the tree density was obtained by using 10 x 10 meter quadrats. In this sampling three size classes were recognized, seedling, sapling, and 1.0-4.0 inch d.b.h. For each size class the following distributions were determined: percentage frequency, percentage density, percentage basal area, density per acre, basal area per acre; and cumulative figures for the relative density, relative basal area, and relative frequency of each species over 1 inch d.b.h. A similar study was carried out on 8.8 acres of a wind-throw area, and on 144 acres of spruce-fir-northern hardwoods forest. In the latter, additional size classes up to 24.0 inches d.b.h. were added. Determining frequencies in randomly distributed quadrats resolved in a positive direction the question of whether fire and wind-throw significantly affect the plant successional trend. Since the tree species in each of the three areas were found to be nearly identical, the Chi-square criterion was employed to decide whether the density distribution was independent of the area. Two significant factors resulted: (1) Of the twenty-one species in the spruce-fir-northern hardwoods forest, thirteen were represented among the eighteen species of the wind-throw area. The distribution of these thirteen species differed significantly in the two areas. (2) Thirteen of the species of the spruce- fir- northern hardwoods forest, were represented in the burn which contained altogether fifteen species. Again, the density distribution differed significantly for the two areas. The hypothesis that the frequency distribution was independent of the area was rejected in both tests since the value of the Chi-square calculated, for the densities in each size class, was significantly different from what could be expected by chance. This substantiated the conclusion that the three unique ecological environments accounted for the quantitative distribution of their species. [TRUNCATED] / 2999-01-01

Thesis (MSc (Conservation Ecology and Entomology)--University of Stellenbosch, 2006. / The Restionaceae is a dominant family in the Fynbos Biome, an area in which fire plays a role as an important disturbance, yet little is known about their population dynamics. Two species of the Restionaceae (Thamnochortus insignis and T. erectus) are economically important as thatching reed and differ in their life-histories. This study aims to determine the effects of variation in life history (sprouter vs. non-sprouter) on the population structure and dynamics of T. erectus (“wyfies riet”, sprouter) and T. insignis (“mannetjies riet”), a non-sprouting species. A matrix-modelling approach based on field data collected by Ball (1995) is used to determine population growth rates, stable stage distributions and stage sensitivity and elasticity for the two species with no disturbance present. The sprouter (T. erectus) shows a positive population growth rate (λ >1) and greater persistence within all stages. The non-sprouting species (T. insignis) shows a negative population growth rate (λ <1) between disturbances as well as greater seed production, germination and growth between stages. Based on the population dynamics of these two species, further research was done to understand the effect of disturbance (harvesting and fire) on these species. A matrix modelling approach was used to determine which disturbance frequency maximises population output and success. Harvesting as well as fire results in a decline in T. insignis populations. A five year frequency for harvesting results in the greatest output of adult plants with the lowest effect on the population, and a fire frequency of 50 to 65 years is recommended. Testing indicates that the model underestimates the number of adults in the population and thus the model is conservative. T. erectus populations grow despite fire or harvesting; thus any reasonable harvesting (3-5 year frequency) and fire (10+ years between fire) regime would ensure population persistence. As data were limited it was not possible to test the results although T. erectus appears resilient to disturbance and therefore a predetermined regime is not as important as in T. insignis. Recommendations to farmers are made based on these results.

Long term fire exclusion has been attempted in Catchment IX (CIX) at Cathedral Peak. Baseline vegetation of CIX was sampled in 1952, with follow-up surveys in 1973, 1986 and 2010. These took place at key times in terms of changes in fire history within the catchment. Complete fire exclusion was achieved between 1973 and 1986, but eight accidental fires burnt part of CIX thereafter. The woody component was resurveyed in 2010 after the latest of thirteen unintended fires had swept through CIX in 2007. This fire burnt about 90% of the catchment. The vegetation of the area not burnt was a distinct community and size structure indicating it had not been burnt by other accidental fires. Partial exclusion of fire over 58 years resulted in vegetation transforming from grassland to a grassland-fynbos-scrub forest mosaic. Erica evansii and Leucosidea sericea, a reseeder and resprouter respectively, were the two dominant species in CIX. These displayed expected responses to a single fire, resulting in dominance shifting from E. evansii (92% mortality) to L. sericea (1.6% mortality). The decrease in E. evansii individuals resulted in a relative increase in community contribution of species not affected by fire. Leucosidea sericea’s post-fire dominance in burnt plots was not apparent in fire-protected areas. A successional trend of colonisation of woody species, predominantly E. evansii and L. sericea, into grassland was observed. Despite occasional fires since 1986 vegetation did not revert to grassland. The emergent woody community was not homogenous. This was attributed to a combination of an irregular pattern of accidental burns and environmental variability within the catchment. The mosaic of distinct grassland, woodland, ecotonal and scrub forest communities are predicted to remain as such.

by Yau Mei-sze. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1996. / Includes bibliographical references (leaves 130-141). / Abstract --- p.i / Acknowledgements --- p.iii / List of Tables --- p.iv / List of Figures --- p.v / Chapter CHAPTER 1 --- INTRODUCTION / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Fire as an ecological factor in Hong Kong --- p.3 / Chapter 1.3 --- Conceptual framework of the study --- p.6 / Chapter 1.4 --- Objectives of the study --- p.10 / Chapter 1.5 --- Significance of the study --- p.12 / Chapter 1.6 --- Organization of the thesis --- p.12 / Chapter CHAPTER 2 --- STUDY AREA / Chapter 2.1 --- Location --- p.14 / Chapter 2.2 --- Climate --- p.16 / Chapter 2.3 --- Geology --- p.18 / Chapter 2.4 --- Soil --- p.19 / Chapter 2.5 --- Vegetation --- p.20 / Chapter CHAPTER 3 --- EFFECTS OF HILL FIRE ON SOIL CHEMICAL PROPERTIES / Chapter 3.1 --- Introduction --- p.21 / Chapter 3.2 --- Methodology --- p.26 / Chapter 3.2.1 --- Sampling --- p.26 / Chapter 3.2.2 --- Soil reaction --- p.27 / Chapter 3.2.3 --- Total Kjeldahl nitrogen (TKN) --- p.27 / Chapter 3.2.4 --- Mineral nitrogen (ammonium and nitrate nitrogen) --- p.27 / Chapter 3.2.5 --- Total phosphorus --- p.28 / Chapter 3.2.6 --- Available phosphorus --- p.28 / Chapter 3.2.7 --- "Exchangeable K, Na, Ca and Mg" --- p.28 / Chapter 3.2.8 --- Exchangeable A1 and H --- p.29 / Chapter 3.2.9 --- Organic carbon --- p.30 / Chapter 3.2.10 --- Carbon : nitrogen ratio --- p.30 / Chapter 3.3 --- Statistical analysis --- p.30 / Chapter 3.4 --- Results --- p.31 / Chapter 3.4.1 --- Effects of fire on soil chemical properties --- p.31 / Chapter 3.4.1.1 --- Soil acidity --- p.31 / Chapter 3.4.1.2 --- Nutrient cations --- p.32 / Chapter 3.4.1.3 --- Total Kjeldahl nitrogen and mineral N --- p.33 / Chapter 3.4.1.4 --- Soil organic matter and C:N ratio --- p.33 / Chapter 3.4.1.5 --- Total and available phosphorus --- p.33 / Chapter 3.4.2 --- Seasonal changes of soil chemical properties after fire --- p.34 / Chapter 3.4.2.1 --- Soil pH and exchangeable acidity --- p.34 / Chapter 3.4.2.2 --- Nutrient cations --- p.35 / Chapter 3.4.2.3 --- Total Kjeldahl nitrogen and mineral N --- p.36 / Chapter 3.4.2.4 --- Soil organic matter --- p.37 / Chapter 3.4.2.5 --- Total and available phosphorus --- p.38 / Chapter 3.5 --- Discussion --- p.38 / Chapter 3.5.1 --- Effects of fire on soil chemical properties --- p.38 / Chapter 3.5.1.1 --- Immediate effects of fire on soil acidity --- p.38 / Chapter 3.5.1.2 --- "Immediate effects of fire on organic matter, N and P" --- p.40 / Chapter 3.5.1.3 --- Immediate effects of fire on cation nutrients --- p.41 / Chapter 3.5.2 --- Seasonal changes of soil chemical properties after fire --- p.42 / Chapter 3.5.2.1 --- Seasonal changes of soil acidity after fire --- p.42 / Chapter 3.5.2.2 --- Seasonal changes of nutrients after fire --- p.43 / Chapter 3.5.3 --- Overall fertility of the fire-affected soil --- p.44 / Chapter 3.6 --- Conclusion --- p.46 / Chapter CHAPTER 4 --- NITROGEN MINERALIZATION AFTER FIRE / Chapter 4.1 --- Introduction --- p.48 / Chapter 4.2 --- Methodology --- p.52 / Chapter 4.2.1 --- In situ incubation --- p.52 / Chapter 4.2.2 --- "Determination of N mineralization, leaching and uptake" --- p.53 / Chapter 4.3 --- Statistical analysis --- p.55 / Chapter 4.4 --- Results --- p.56 / Chapter 4.4.1 --- Seasonal variations of nh4-N and no3-N --- p.56 / Chapter 4.4.2 --- "Net ammonification, leaching and uptake" --- p.57 / Chapter 4.4.3 --- "Net nitrification, leaching and uptake" --- p.58 / Chapter 4.5 --- Discussion --- p.59 / Chapter 4.5.1 --- Post-fire ammonification --- p.59 / Chapter 4.5.2 --- Post-fire nitrification --- p.62 / Chapter 4.5.3 --- Net nitrogen mineralization of the burnt soil --- p.65 / Chapter 4.6 --- Conclusion --- p.68 / Chapter CHAPTER 5 --- EFFECTS OF LIME AND PHOSPHORUS ON THE MINERALIZATION OF NEW BURNT SOIL / Chapter 5.1 --- Introduction --- p.70 / Chapter 5.2 --- Methodology --- p.73 / Chapter 5.2.1 --- Sampling of soil --- p.73 / Chapter 5.2.2 --- Lime treatment --- p.73 / Chapter 5.2.3 --- Phosphorus treatment --- p.74 / Chapter 5.2.4 --- Combined lime and phosphate treatment --- p.74 / Chapter 5.3 --- Statistical analysis --- p.75 / Chapter 5.4 --- Results --- p.75 / Chapter 5.4.1 --- Chemical properties of the unamended soil --- p.75 / Chapter 5.4.2 --- Lime treatment --- p.76 / Chapter 5.4.2.1 --- Effect of lime on nh4-N production --- p.76 / Chapter 5.4.2.2 --- Effect of lime on no3-N production --- p.78 / Chapter 5.4.2.3 --- Effect of lime on PO4 production --- p.78 / Chapter 5.4.2.4 --- Effect of lime on exchangeable A1 --- p.78 / Chapter 5.4.3 --- Phosphorus treatment --- p.79 / Chapter 5.4.3.1 --- Effect of phosphorus on NH4-N production --- p.79 / Chapter 5.4.3.2 --- Effect of phosphorus on NO3-N production --- p.80 / Chapter 5.4.3.3 --- Effect of phosphorus on PO4 production --- p.80 / Chapter 5.4.4 --- Combined lime x P amendment and mineralization of N and P --- p.81 / Chapter 5.4.4.1 --- Effect of lime x P on nh4-N production --- p.81 / Chapter 5.4.4.2 --- Effect of lime x P on NO3-N production --- p.83 / Chapter 5.4.4.3 --- Effect of lime x P on po4 production --- p.83 / Chapter 5.5 --- Discussion --- p.83 / Chapter 5.5.1 --- Effect of soil acidity on ammonification --- p.83 / Chapter 5.5.2 --- Effect of soil acidity on nitrification --- p.88 / Chapter 5.5.3 --- Effect of lime on the mineralization of P --- p.89 / Chapter 5.5.4 --- Effect of combined lime x P on the mineralization of N and P --- p.89 / Chapter 5.6 --- Conclusion --- p.90 / Chapter CHAPTER 6 --- VEGETATION REGENERATION AND NUTRIENT COMPOSITION AFTER FIRE / Chapter 6.1 --- Introduction --- p.92 / Chapter 6.2 --- Methodology --- p.96 / Chapter 6.2.1 --- Vegetation regeneration analysis --- p.96 / Chapter 6.2.2 --- Chemical analysis --- p.96 / Chapter 6.3 --- Results --- p.97 / Chapter 6.3.1 --- Vegetation regeneration --- p.97 / Chapter 6.3.2 --- Nutrient composition of regenerated species --- p.100 / Chapter 6.3.2.1 --- Total Kjeldahl nitrogen --- p.100 / Chapter 6.3.2.2 --- Total phosphorus --- p.101 / Chapter 6.3.2.3 --- Potassium --- p.102 / Chapter 6.3.2.4 --- Calcium --- p.103 / Chapter 6.3.2.5 --- Magnesium --- p.104 / Chapter 6.3.2.6 --- Sodium --- p.105 / Chapter 6.4 --- Discussion --- p.106 / Chapter 6.4.1 --- Vegetation regeneration after fire --- p.106 / Chapter 6.4.2 --- Nutrient composition of regenerated species --- p.108 / Chapter 6.4.3 --- Recovery and erosion control --- p.112 / Chapter 6.5 --- Conclusion --- p.112 / Chapter CHAPTER 7 --- CONCLUSION / Chapter 7.1 --- Summary of findings --- p.114 / Chapter 7.2 --- Implications of the study --- p.118 / Chapter 7.2.1 --- Is hill fire hazardous or beneficial to the local environment? --- p.118 / Chapter 7.2.2 --- Mechanisms to conserve nutrients in a fire-prone environment --- p.121 / Chapter 7.2.3 --- Natural regeneration or reforestation? --- p.122 / Chapter 7.3 --- Limitations of the study --- p.123 / Chapter 7.4 --- Suggestion for future study --- p.126 / REFERENCES --- p.130