Understanding how commercial forests can be managed to benefit wildlife has important conservation implications, as silvicultural landscapes occur globally and have high economic value. In this study, I compared two habitat types in southeastern Louisiana, even-aged loblolly pine ( Pinus taeda) and bottomland hardwood forests, both used for breeding by Swainson's Warbler (Limnothlypis swainsonii; SWWA). I investigated habitat quality and habitat selection patterns of SWWA to (1) assess the conservation value of pine plantations for understory-nesting birds, (2) identify ecological factors important in habitat selection at multiple scales, and (3) contribute needed information on the natural history and status of a species of conservation concern The density of breeding pairs, timing of nesting, clutch size, hatching rates, and reproductive success of SWWA did not differ significantly between habitats. These results, coupled with similar patterns of habitat use at the nest site, suggest that the habitats are ecologically analogous for breeding. Similarities in morphology and behavior also suggest that ecotypic variation does not account for differences in ecological success or patterns of habitat selection in the two forest types Predictions about habitat selection mechanisms were tested based on the foraging behaviors and nesting requirements of SWWA at specific scales. I found support for four hypotheses (Foraging Substrate, Potential Nest Site, Nest Decoy, and Nest Concealment), demonstrating that SWWA use different cues at the habitat, territory, nest patch, and nest site scales, but consistently across habitat types. Vegetation characteristics contributing to the nesting and foraging needs of this species served as mechanisms for habitat selection These results support the conclusion that SWWA has expanded its breeding range into an anthropogenic habitat that meets its basic nesting requirements, despite structural and floristic differences between the two forest types. The implication of these findings is that the conservation value of the enormous area of commercial pine plantations in the southeastern United States can be significantly augmented by appropriate management choices / acase@tulane.edu

The woody vegetation in 317 plots totaling 3.17 hectares was sampled in the forest of the Calakmul Biosphere Reserve, Campeche, Mexico. All stems greater than 2.5 cm diameter at breast height were measured; diameter and vernacular name (Maya or Spanish), along with scientific name, if known in the field, estimated height, slope, presence of ruins, and soil type were recorded. A total of 16,113 stems were measured, representing 138 taxa in 44 families; 105 taxa were identified to species level, 24 to genus, and 5 to family. Vines were only counted as a life form, due to the difficulty of securing specimens for determination. Three uncommon taxa were not identified, described only by Maya common name. Using Maya soil classification terminology, data were used to describe major plant communities on the most important soil types, and to develop an Indicator Species Analysis. Six possible Indicator Species were analyzed by an autobinomial regression, using a Gibbs sampler based on the Markov Chain Monte Carlo method, to test the statistical significance of the Indicator Values. The coefficients for three species were positive and statistically significant; the coefficients for two species were negative and statistically significant; and the coefficient for one species was not statistically significant Brosimum alicastrum (Moraceae) (n.v. ramon) was the dominant tree (measured in square decimeters per hectare) overall (all plots on all soils considered together), and was also the dominant tree on yaxhom (upland) soil, near ruins, on ruins, and on kakab, an anthropogenic soil created by many centuries of human activity on the site. Indicator species analysis showed B. alicastrum to be a strong indicator for the presence of ruins and anthropogenic soil, taking into account neighbor effects. Talisia olivaeformis and Manilkara zapota also show a significant positive association with ruins and the areas around ruins. T. olivaeformis is an important fruit tree in the Yucatan Peninsula today, and was undoubtedly so in antiquity. M. zapota yields fruit, latex, and a very hard, durable wood. The autobinomial regression technique confirmed the statistical significance of the indicator values. Haematozylum campechianum (Leguminosae) was the dominant tree on akalche soil, which is found in lowland seasonal swamps (bajos) The findings, including plant community demographics, statistical and graphic techniques, and historical and archaeological evidence, provide confirmation for the thesis that Brosimum alicastrum is a strong and reliable indicator of sites of former human habitation. These findings also support the hypothesis that B. alicastrum was managed and selected by the Lowland Maya as a staple food. The importance of B. alicastrum as a reliable food source in ancient times, especially before the introduction of Zea mays into the Maya lowlands, probably led to the intensive cultivation, management, and artificial selection of the species. The ramon on the site in modern times likely represents a population which has co-evolved in response to large-scale changes in the landscape and ecology of the forest of southern Campeche and nearby areas. Therefore, the abundance of B. alicastrum on ruin sites can be most parsimoniously explained as a kabab effect, rather than a ruin effect / acase@tulane.edu

Habitat fragmentation impacts on bird communities are relatively well studied in the temperate zone, where brood parasites and non-forest predators are the main causes of declining avian biodiversity. However, life history traits of tropical species suggest different and more diverse effects of habitat fragmentation on tropical bird communities. This dissertation used historical data and quantitative comparisons of fragmented and control sites to infer causes and patterns of tropical avian community response to fragmentation in Central America. Particular ecological guilds, namely forest understory insectivores, mixed-species flock participants, and birds that nest on or near the ground declined or disappeared from La Selva Biological Station, Costa Rica since the 1950s as the site became increasingly isolated from other forest. Spot-maps of twenty-two insectivorous bird species at La Selva in the 1970s indicate that insectivore populations were probably never large enough to be viable, emphasizing the need for larger reserves given the low density of many tropical forest species. Comparisons of four forest sites (24.6-1200 ha) to an non-fragmented control site in southeastern Nicaragua show significant reduction in biodiversity, corresponding decline in total bird abundance, and changes in community composition, even in the larger sites. Lack of change in the Nicaraguan control site suggests landscape changes rather than climate change is the most parsimonious explanation for community changes in the fragments. Finally, comparison of community changes in two large isolated forest reserves, La Selva and Barro Colorado Island, Panama, demonstrate similar patterns of losses of insectivores and low nesting species. However, landscape level and climatic differences between the two sites also affect the ability of some species to persist in remaining forest. Overall, this dissertation suggests that deterministic factors, especially ecological characteristics, put particular species at risk to landscape changes. No single mechanism appears to explain all the patterns, but small population size, poor dispersal ability, and increase in nest depredation are implicated by this study. Further investigation is needed to assess the relative importance of these and other mechanisms. Moreover, trophic cascades involving other taxa are predicted as a result of the lack of ecological replacement of disappearing specialized forest insectivores / acase@tulane.edu

The Middle Rio Grande River (MRGR) is the main source of fresh water for the state of New Mexico. Located in an arid area with scarce local water resources, this has led to extensive diversions of river water to supply the high demand from municipalities and irrigated agricultural activities. The extensive water diversions over the last few decades have affected the composition of the native riparian vegetation by decreasing the area of cottonwood and coyote willow and increasing the spread of invasive species such as Tamarisk and Russian Olives, harmful to the river system, due to their high transpiration rates, which affect the river aquatic system. The need to study the river hydrological processes and their relation with its health is important to preserve the river ecosystem. To be able to do that a detailed vegetation map was produced using a Utah State University airborne remote sensing system for 286 km of river reach. Also a groundwater model was built in ArcGIS environment which has the ability to estimate soil water potential in the root zone and above the modeled water table. The Modified Penman- Monteith empirical equation was used in the ArcGIS environment to estimate riparian vegetation ET, taking advantage of the detailed vegetation map and spatial soil water potential layers. Vegetation water use per linear river reach was estimated to help decision makers to better manage and release the amount of water that keeps a sound river ecosystem and to support agricultural activities.

Working with and designing with other, non-human, biological species is one of the deepest challenges facing architecture today and human development in general. Rather than to preserve, or cater to outside species "How to Design with the Animal" demonstrates that Architecture can actively participate in the life around it. By directing, responding and intervening in the sensorial (audible, olfactory, or haptic) ranges of individual species, architecture and infrastructure can become redefined as animal players in a much larger system. As a sensorial device architecture would become part attractor, part program container and part animal/architecture interface. Animals and ecosystems would then begin to influence the siting and design of individual buildings and they in turn would attract individual species while also being subject to larger migratory, or environmental patterns. And, more than providing a space for program, a new posthumanist architecture could offer the visitor with the experience of participating in a conversation with another animal.

There was a long-term decline in northern bobwhite (Colinus virginianus, NBW) abundance since the 1920s, based on the Christmas Bird Count (CBC) data, but with substantial spatial and temporal variations across its range. There were four recognizable periods in the spatial and temporal dynamics of NBW abundance between 1920 and 1990. Severe weather conditions and habitat loss due to land use change appeared to be the most important factors influencing the long-term trends and spatial patterns in NBW abundance. A spatial database of agricultural land use was developed based on the Census of Agriculture to evaluate the spatial patterns of land use variables over NBW range from 1920 to 1997. The results showed dramatic changes in land use over the period and the influence of socio-economic events, natural disasters and federal agricultural policies on the dynamics of land use pattern, and potential implications to NBW abundance were identified. Replacement of less intensive agriculture with intensive monoculture production and mechanization coincided with World War I, and the post-war collapse in agriculture and the economy, partly associated with the Dust Bowl, enhanced this trend. Monoculture production and clean farming practices were further intensified during World War II and the years following the war. These land use changes had overall negative effects on NBW habitat. Analysis of the changes in spatial pattern of NBW abundance in the Great Plains region during the severe drought of the 1950s showed a significant decline in NBW abundance during the drought and a contraction of the NBW range at its western edge. The post-drought recovery exhibited spatial patterns significantly different from the predrought ones. These findings suggested that severe drought caused short-term changes in regional distribution of NBW and range contraction, as well as long-lasting, largescale changes in spatial distribution of NBW abundance. This study provides scientific basis for landscape planning and management. Evaluating the spatial pattern and temporal dynamics of certain wildlife species at large scales over long-term periods, and identifying potential causal factors are key strategies for implementing innovative and sustainable approaches to planning and policy. Such strategies will have a significant impact on future landscape and wildlife species.

Thesis (Ph.D.)--Indiana University, Dept of Public and Environmental Affairs and the Dept. of Political Science, 2009. / Title from PDF t.p. (viewed on Feb. 8, 2010). Source: Dissertation Abstracts International, Volume: 70-05, Section: A, page: 1775. Adviser: Elinor Ostrom.

The objective of this study was to evaluate the effects of mesquite overstory removal and modifications of soil properties due to mulching treatments on herbaceous production. The three overstory treatments were complete removal of mesquite overstory with no removal of regrowth, complete removal of mesquite overstory with removal of regrowth and an untreated control. The mulching treatments included applications of chip mulch, commercial compost, lopped-and-scattered mesquite branchwood and a control. Both overstory treatments resulted in an increase of over 20% in total annual herbaceous production. The overstory treatment of complete removal of mesquite overstory with no removal of regrowth had the greatest impact on fall production of native herbaceous species during years of relatively high precipitation, at times increasing production by almost 2-fold. Mulching treatments had no effect on herbaceous production; however, soil pH and plant available phosphorus was affected by some of the mulching treatments.

The use of active and passive remote sensing systems for relating forest spatial patterns to fire history was tested over one of the Arizona Sky Islands. Using Landsat Thematic Mapper (TM), Shuttle Imaging Radar (SIR-C), and data fusion I examined the relationship between landscape metrics and a range of fire history characteristics. Each data type (TM, SIR-C, and fused) was processed in the following manner: each band, channel, or derived feature was simplified to a thematic layer and landscape statistics were calculated for plots with known fire history. These landscape metrics were then correlated with fire history characteristics, including number of fire-free years in a given time period, mean fire-free interval, and time since fire. Results from all three case studies showed significant relationships between fire history and forest spatial patterns. Data fusion performed as well or better than Landsat TM alone, and better than SIR-C alone. These comparisons were based on number and strength of significant correlations each method achieved. The landscape metric that was most consistent and obtained the greatest number of significant correlations was Shannon's Diversity Index. Results also agreed with field-based research that has linked higher fire frequency to increased landscape diversity and patchiness. An additional finding was that the fused data seem to detect fire-related spatial patterns over a range of scales.

Computer models used to predict the pattern and rate of spread of fire in grasslands as well as other vegetation types rely on various inputs for their calculations. Because of the direct effect they have on the quantity of fuel available to carry a fire and the effects of moisture on the potential for fuel available to carry a fire and the effects of moisture on the potential for fuel to begin burning and to sustain a fire, fuel loading measurements, which are similar to production measurements in grasslands, and estimates of fuel moisture are two important variables to be considered when modeling fire behavior. The objective of this project is to determine if there is a relationship between measured environmental variables and the fuel moisture values at the same sample points which can be modeled with GIS data and neural networks. This study was carried out using a combination of field sampled data and common GIS data layers. The results demonstrate the potential for neural network analysis in this type of environmental problem.