acase@tulane.edu

The Choice Modelling technique is an emerging technique which appears to have strengths relative to other non-market valuation techniques. The latter group are important in the assessment of the tradeoffs involved in environmental and resource use tradeoffs. However, the use of these techniques is often criticised where ethical and moral frameworks are involved, where it is unclear how difficult choices are being framed against each other, or where it is unclear how values change according to the scope of the amenity under consideration The primary focus of the thesis is on the development of the Choice Modelling technique, which provides a richer information set to researchers than other techniques such as Contingent valuation method. However, the richness of this data is offset to some degree by the complexity of application, where careful attention is needed for design, application and analytical stages. In this thesis, a series of four Choice Modelling experiments are reported, as well as two small Contingent Valuation experiments. The Choice Modelling experiments were centred on the estimation of values that Australians might hold for rainforest conservation in Vanuatu. In order to frame and scope the tradeoffs of interest within the broad pool of substitute goods (such as rainforest conservation opportunities in other countries), the Choice Modelling technique appeared more suitable than the single tradeoff preservation of the Contingent Valuation method. The results of Choice Modelling experiments involved sets of parameters indicating that the probability of choice depended on a number of attributes used to make up the conservation profiles together with the influence of unobserved attributes. As a willingness-to-pay variable was included within the attributes making up choice profiles, estimates of value were available by predicting how changes in particular attributes could be offset by changes in the willingness-to-pay variable. The major conclusions of the research presented in the thesis were that the involvement with ethical and moral frameworks does not invalidate the use of non-market valuation techniques, and that the Choice Modelling technique has strengths in relation to scooping and framing issues. In particular, the research demonstrates that the information generated from an experiment can be used in an iterative approach to develop more accurate models of choice. As well, the research shows that the amenity of interest, rainforest conservation in Vanuatu, can have positive values for Australian residents relative to other conservation opportunities.

A variety of aquatic habitats with different levels of potential predators are available to larval amphibians in Central Amazon rainforest. The anuran community at Reserva Florestal Adolfo Ducke, 25 km east of Manaus, Amazonas, Brasil, was studied to determine which species have eggs and/or larvae in water and how those larvae are distributed in time and space. The temporal and spatial distribution of potential predators as well as abiotic characteristics of these waterbodies were determined simultaneously to test for correlations with the distribution of tadpoles. The distribution of tadpoles was strongly related to fish predation pressure. Several tadpole species were found only in waterbodies with high fish abundance and thus have the ability to survive with fish. Most of these tadpoles were found to be unpalatable in controlled experiments. Unpalatability is the major adaptation allowing the coexistence of tadpoles and fish and is thus a major factor affecting tadpole community composition in this system. Controlled experiments showed that fish do not eat anuran eggs while the tadpoles of Leptodacrylus knudseni and Osteocephalus taurinus ate all types of eggs offered. The percentage of anurans with aquatic oviposition was positively related to fish abundance and negatively related to the occurrence of species of tadpole that ate eggs in experiments. These findings suggest that the present patterns of anuran distribution represent an evolutionary response to predation on the eggs and larvae. Contrary to the models of Heyer et al. (1975) and Wilbur (1984), desiccation and predation-pressure were not the major factors affecting species richness within waterbodies of the RFAD rainforest. In support of the model of Heyer et al. (1975), anuran species richness was correlated with the size of the waterbody. This could be because the size of the waterbody is related to increased complexity and availability of microhabitats. The range of volumes of waterbodies was also found to directly affect species richness of the RFAD community. While predation appeared to have a limited effect on species richness of individual ponds, predation-pressure was found to have a major influence on species composition. Anuran eggs and larvae survived with specific predators by possessing particular survival-traits (e.g. unpalatability and oviposition strategies). However, survival-traits were not effective against all predators in all habitats. The distribution of different predators among ponds provides a patchy environment on a local scale (i.e. within ponds). When combined with the variety of survival-traits exhibited by the anuran species, this spatial patchiness in predation contributes towards species richness within the anuran community of the RFAD rainforest.

Human transformation of the Earth’s land surface has far-reaching and important consequences for the functioning of hydrological and hydrochemical processes in watersheds. In nowadays land-use change from forest to pasture is a major issue in particular in the tropics. A sustainable management of deforested areas requires an in-depth understanding of the water and nutrient cycle. On this basis we compared the involved hydrological pathways for rainfall to reach streams and the nutrient budgets of a tropical rainforest and a pasture. In addition we studied the links of hydrochemical differences to differences of the relative importance of flowpaths. This study was conducted in the southwestern part of the Brazilian Amazon basin. An intensive hydrological and hydrochemical sampling and monitoring network was set up. The results indicate that the hydrology was modified in many ways due to land-use change. The most important alteration was the increased importance of the fast flowpath overland flow. Solute exports were in particular linked to the increased volume of overland flow that resulted from the land-use change. An additional reason for the increased nutrient exports from the pasture are the high concentrations of these nutrients in pasture overland flow probably as a due to cattle excrements. Tight nutrient cycles with minimal nutrient losses could not be maintained after the land-use change. This study provides the first attempt to quantify the respective nutrient losses. / Die Zerstörung von natürlicher Vegetation kann weit reichende Folgen auf den Wasser- und Nährstoffhaushalt von Ökosystemen haben. Der Landnutzungswandel vom Wald zur Weide ist heute in den Tropen ein wichtiges Thema. Eine nachhaltige Nutzung abgeholzter Gebiete setzt ein fundiertes Wissen des Wasser- und Nährstoffhaushaltes voraus. Darauf aufbauend wurden in dieser Studie das Abflussverhalten und die Nährstoffbilanzen von einem tropischem Regenwald und einer Weide verglichen. Außerdem wurde untersucht inwieweit die Nährstoffbilanzen vom Abflussverhalten abhängen. Die Untersuchungsgebiete liegen im südwestlichen brasilianischen Amazonasgebiet. Ein umfangreiches System zur Aufnahme von hydrologischen Daten und zum Sammeln von Wasserproben wurde aufgebaut. Die Ergebnisse haben gezeigt, dass sich das Abflussverhalten durch die Landnutzung geändert hat. Die wichtigste Änderung vom Wald zur Weide war der gesteigerte Anteil des schnellen Wasserabflusses auf der Geländeoberfläche. Hieraus resultierten gesteigerte Nährstoffausträge aus der Weide gegenüber dem Wald. Ein weiterer Grund für die gesteigerten Nährstoffausträge sind die hohen Konzentrationen dieser Stoffe im Oberflächenabfluss der Weide, die vermutlich mit den Ausscheidungen des Viehs zusammenhängen. Es hat sich also gezeigt, dass der quasi-geschlossene Nährstoffkreislauf nach der Landnutzungsänderung nicht aufrecht erhalten werden konnte. Diese Arbeit liefert den ersten Versuch diese Nährstoffverluste zur quantifizieren.

<p>Amazonia contains the largest remaining tracts of undisturbed tropical forest on earth, and is thus critical to international nature conservation and carbon sequestration efforts. Amazonian forests are notoriously difficult to study, however, due to their species richness and inaccessibility. This has limited efforts to produce the accurate, high-resolution biodiversity maps needed for conservation and development. The aims of the research described here were to identify efficient solutions to the problems of tropical forest inventory; to use these methods to identify floristic patterns and their causes in western Amazonia; and propose new means to map floristic patterns in these forests.</p><p> Using tree inventories in the vicinity of Iquitos, Peru, I and a colleague systematically evaluated methods for rapid tropical forest inventory. Of these, inventory of particular taxonomic groups, or taxonomic scope inventory, was the most efficient, and was able to capture a majority of the pattern observed by traditional inventory techniques with one-fifth to one-twentieth the number of stems and species. Based on the success of this approach, I and colleagues specifically evaluated two plant groups, the Pteridophytes (ferns and fern allies) and the Melastomataceae (a family of shrubs and small trees), for use in rapid inventory. Floristic patterns based on inventories from either group were significantly associated with those based on the tree flora, and inventories of Pteridophytes in particular were in most cases able to capture the majority of floristic patterns identified by tree inventories. These findings indicate that Pteridophyte and Melastomataceae inventories are useful tools for rapid tropical forest inventory.</p><p> Using Pteridophyte and Melastomataceae inventories from 138 sites in northwestern Amazonia, combined with satellite data and soil sampling, I and colleagues studied the causes of vegetation patterns in western Amazonian forests. On the basis of these data, we identified a floristic discontinuity of at least 300km in northern Peru, corresponding to a 15-fold difference in soil cation concentrations and an erosion-generated geological boundary. On the basis of this finding, we assembled continent-scale satellite image mosaics, and used these to search for additional discontinuities in western Amazonia. These mosaics indicate a floristic and geological discontinuity of at least 1500km western Brasil, driven by similar erosional processes identified in our study area. We suggest that this represents a chemical and ecological boundary between western and central Amazonia.</p><p> Using a second network of 52 pteridophyte and soil inventories in northwestern Amazonia, we further studied the role of geology in generating floristic pattern. Consistent with earlier findings, we found that two widespread geological formations in western Amazonia differ eight-fold difference in soil cation concentrations and in a majority of their species. Difference in elevation, used as a surrogate for geological formation, furthermore explained up to one-third of the variation in plant species composition between these formations. Significant correlations between elevation, and cation concentrations and soil texture, confirmed that differences in species composition between these formations are driven by differences in soil properties. On the basis of these findings, we were able to use SRTM elevation data to accurately model species composition throughout our study area.</p><p> I argue that Amazonian forests are partitioned into large-area units on the basis of geological formations and their edaphic properties. This finding has implications for both the ecology and evolution of these forests, and suggests that conservation strategies be implemented on a region-by-region basis. Fortunately, the methods described here provide a means for generating accurate and detailed maps of floristic patterns in these vast and remote forests.</p> / Dissertation

The objectives of my research were twofold: 1) to evaluate new technologies (camera traps and a new type of GPS collar) for studying large mammals in tropical forests, and 2) to study the ecology of the lowland tapir (Tapirus terrestris) in the Peruvian Amazon. Camera traps proved to be an efficient tool for mammal inventories in tropical forests. They recorded 24 out of 28 terrestrial medium and large sized mammal species with a survey effort of 2340 camera days. Camera traps were also able to reveal important information on habitat use, activity patterns and the use of mineral licks for five Amazonian ungulate species. There was a high spatial overlap between all the species with the grey brocket deer being the only species that was restricted to terra firme forest. White-lipped peccaries, tapirs and red brocket deer frequently used mineral licks, whereas collared peccaries and grey brocket deer were hardly ever observed at licks. A new type of GPS collar (TrackTag) tested in this study performed well under the dense canopy of a tropical forest. Position success rates of 87% for stationary collars and 48% for collars placed on tapirs were comparable to data obtained with GPS collars in temperate forests. The mean location error for stationary collars inside the forest was 28.9 m and the 95% error was 76.8 m. GPS collars placed on six tapirs for seven to 182 days showed home range sizes of 102 to 386 hectares. Tapirs were mainly nocturnal and areas used for foraging during the night differed from resting sites used during the day. Tapirs could walk up to 10 km to visit a mineral lick. Visits were irregular at intervals of a few days up to 36 days. The analysis of 135 tapir dung samples showed that tapirs ingest seeds of over 120 plant species. Seeds were found throughout the year but monthly species diversity was related to fruit availability. The size distribution of ingested seeds was related to availability. Most seeds were less then 10 mm wide, but seeds up to 25 mm were found. Both camera traps and TrackTag GPS collars greatly increased the possibilities for studying large rainforest mammals. The two technologies collect complementary information and each one is suited for a different set of questions.

Tree squirrels play an important role in the maintenance of forest ecosystems by functioning as seed and fungal spore dispersers, forest regenerators, and prey for forest predators. The highest species richness for tree squirrels occurs in tropical forests and these species are also the least studied. We conducted distance sampling to estimate population density, measured habitat variables to investigate forest characteristics that influence habitat selection and feeding site selection at three different scales, and conducted observations to obtain knowledge about activity pattern and behavior of Neotropical pygmy squirrels and Amazon red squirrels in the Peruvian Amazon. Density of Neotropical pygmy squirrels was 0.10 and 0.14 individuals/ha for 2009 and 2010. Activity peaked in early morning, squirrels were found mainly in the canopy but never on the ground, and frequency of behaviors differed by time and story level. Neotropical pygmy squirrels used mainly high and low restinga and areas that had more large trees. Squirrels also used species of trees disproportionately to availability. Neotropical pygmy squirrels seem to be associated with features related to mature forests. Amazon red squirrels use mainly high and low restinga and selected Astrocaryum and Attalea palm trees that were taller and larger as foraging sites compared to random locations. Amazon red squirrels used all vertical strata of the forest and the main behaviors observed were travel and forage. Behaviors were similar among time periods but differed in frequency by vertical strata. Although Amazon red squirrels used vegetation communities differently than their availability and selected for tree characteristics, they did not select for site characteristics and this is different from other tree squirrel species. We also conducted surveys during a wet and a dry year to investigate and estimate diversity of diurnal mammals. We assessed the vertical strata of the forest to determine if diversity index varied by story level, and estimated alpha, beta, and gamma diversity. Overall mammal diversity did not differ between wet and dry years. Diversity index differed by story level between years, but was the highest in the canopy for both years. Alpha diversity was higher in the dry year, and gamma and beta diversity were higher in the wet year. Frequency of sightings of species was influenced by time of day and varied by story level. Protection of continuous, mature forests with large canopies has important conservation implications as these areas most likely protect the greatest diversity of mammals while also providing shelter and food for other taxa.

The processes used to negotiate novel forms of environmental governance being deployed in the North and Central Coast of British Columbia, known as the Great Bear Rainforest, provide useful insights into the kinds of efforts that may be required to effectively address contemporary environmental problems. Through various and complex political processes – constituted by many actors – a novel set of agreements, known as the Great Bear Rainforest Agreements, arguably emerged to resolve a conflict over the management of BC’s forests, a long standing and contentious issue in the province. This thesis first examines the wider limitations of institutions of governance to effectively address environmental problems and efforts to respond to these problems, particularly by environmentalists. Second, it tells the story of the Great Bear Rainforest Agreements, and examines their wider implications for participants of the negotiations and more generally. Overall this thesis argues that the Great Bear Rainforest negotiations can provide instructive lessons to institutions of governance by demonstrating how deliberative processes can help ease some of the structural tensions that condition environmental conflicts in Canada. Second, First Nations in the region played a crucial role in the Great Bear Rainforest negotiations, and the outcomes of this role are likely to have significant implications for future resource conflicts in the province. Third, the role of environmentalists in decision making in British Columbia is evolving. / Graduate

No description available.

This thesis investigates the variability in management practices on coffee and banana farms in an attempt to identify practices that reduce the environmental impact of export crop production. Different banana production systems are studied to determine their level of environmental impact. Insect sampling and bird surveys are used to assess the level of ecological quality on banana farms and their surrounding environments. The first two studies are based on interview methods and focus more on the social aspects of the production system. Paper I identifies how farmers utilize labor and herbicides in weed control practices, and found that small-scale coffee farmers overuse herbicides when their relative use of herbicides to labor to control weed densities is compared to their large-scale counterparts and small-scale organic producers. Paper II attempts to identify variability in management practices for the production of export bananas, but instead finds that there is only one type of export banana production system. However, there are lessons to be learned from organic and banana-coffee intercropping systems of production. Papers III-V use the information gathered in the interview studies of Paper II to give context to the results from analysis of ecological indicators collected from banana farms. Paper III is a comparison of insect community composition on high-input, low-input and organic banana farms. Paper IV is an analysis of aquatic macroinvertebrate in surface water sites upstream and downstream of banana farm canal entry points. Finally, Paper V is a comparison of ecological effects of management practices between Rainforest Alliance certified farms and non-RainforestAlliancecertified farms. Results showed that low-input banana production is not as good as organic production with regards to ecological impact, but it can still make a difference when compared to high-input banana production. Rainforest Alliance certified farms, however, are not low-input systems and the changes that they make in production practices are not enough to influence the quality of the ecological system. These results are encouraging for low-input production systems, but show that standards for Rainforest Alliance certification need to be tougher in order to make an impact on ecological indicators. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 3: Submitted. Paper 4: Submitted. Paper 5: Manuscript.