We investigated whether group-selection provides habitat of similar quality for early-successional shrubland-nesting birds as does clearcutting. There was no difference in avian reproductive success between clearcuts and groupcuts, indicating that clearcuts and groupcuts provide habitat of similar quality for early-successional shrubland-nesting birds. We studied Chestnut-sided Warblers (Dendroica pensylvanica) nesting in 29 patches of regenerating northern hardwoods forest 0.15–0.69 ha in area to determine whether the ecology of this species is affected by patch size or shape. Chestnut-sided Warbler density was higher, and pairs initiated nesting later in smaller patches, yet patch size was unrelated to fledging success or nest predation rates and patch area. Territory density, nest initiation dates, fledging success and nest predation rates were unrelated to patch shape. We compared nest predation rates between groupcut and clearcut borders (0–5 m from edges) and forest interior areas (45–50 m from edges) using artificial shrub nests baited with Zebra Finch (Taeniopygia guttata) eggs. The probability of a nest being depredated was higher in edge areas than forest interior areas (P = 0.02) and was independent of nest concealment, nest height, or whether the nest was adjacent to a clearcut or a groupcut (P = 0.18). We compared survival rates of used natural nests baited with House Sparrow (Passer domesticus) eggs with survival rates of active bird nests at the same sites. Survival rates of artificial nests (27.7%) were significantly lower than nest survival rates of natural nests (58.6%). We suggest that lack of parental defense is a contributing factor responsible for higher predation rates on artificial nests, and is likely to be a potential confounding factor in future nest predation experiments using artificial nests. We studied patterns of plumage variation in the Chestnut-sided Warbler to determine if plumage brightness was related to reproductive performance. There were no relationships between plumage brightness and reproductive success of either male or female Chestnut-sided Warblers. Adult males and females were brighter than subadult males and females, however, adult and subadult males and females fledged as many young as adult males and females. Thus, delayed plumage maturation in the Chestnut-sided Warbler is not associated with decreased reproductive output in subadult birds. We suggest that the duller plumage of subadult Chestnut-sided Warblers is more likely a reliable indicator of subordinate status, and that delayed plumage maturation serves in this species to reduce aggression from adult birds.

Many areas of New Guinea remain poorly sampled, hindering conservation planning efforts. Endemic species significantly contribute to explaining a peak in non-flying mammal diversity at mid-elevations, even after removal of boundary effects. When corrected for area, effects of diet and body size become relevant. Diversity of non-eutherians declines with elevation similar to rodents. Folivores drop in diversity with elevation more markedly than carnivores. Smaller-bodied mammals drop in diversity more markedly than larger-bodied ones. Field surveys at Mt. Stolle produced 3 new species records for Sandaun Province of Papua New Guinea, and 5 new species records for the Telefomin area. I collected data on radio-collared painted ringtails, including: body measurements, home range sizes, survival rates, waking hours spent eating, walking and resting, hours of activity and activity levels. Male painted ringtails are larger than females; males are more active and heavier males return later. Males walk more than females, and heavier males walk more. The male survival rate is one-sixth that of females. Male home ranges overlap with those of two or more females. Painted ringtails are almost entirely folivorous, consuming at least 75 tree species. Bark is consumed from at least five species, two of which were sought significantly beyond their abundance at the site. Selectivity in foliage consumed is present at both the species and family levels of trees, and proximity of diet trees to dreys plays a role in selection. The top 10 species most frequently consumed by males and females do not differ, but the top 10 families do differ. The painted ringtail diet is more folivorous and the tree species composition is significantly different than that of the larger sympatric coppery ringtail and mountain cuscus. Bark consumed by painted ringtails contained calcium, potassium and magnesium levels significantly higher than that found in control trees (conspecifics and other species). Significantly more adult male painted ringtails (14 of 21) were captured at bark trees than adult females (three of 17) or juvenile males (one of six); juvenile females were equally captured at and away from these trees (six of 12).

By studying crown structure, leaf area index (LAI), and light interception during the first 3.5 years of development, I assessed the patterns of above-ground space partitioning and stand dynamics in monocultures and mixtures of three tree species (Cedrela odorata, Cordia alliodora, and Hyeronima alchorneoides). Plantations were established in the tropical rain forest of Costa Rica. To understand species differences during the period of free growth, I measured leaf distribution, crown shape, and biomass allocation strategies of each species at age one year. To compare stands dynamics among monocultures and mixtures I obtained the size, crown shape, and relative position of plants at regular time intervals between age 1.5 and 3.5 years. Stand-level measurements of LAI, and canopy light transmission complemented these individual-tree measurements. Before the onset of competition, there was a statistically significant multivariate difference in crown architecture among the three species. The mean dry biomass (grams/tree)was 990.0 in Cedrela, 665.3 in Cordia, and 1281.4 in Hyeronima. Proportionally Cedrela allocated more biomass into roots than the other two species. Biomass allocation within crowns was correlated with specific above-ground architecture. Differences in stand composition caused major modification in several morphological traits. On average, the performance of Cordia and Hyeronima individuals growing in mixtures exceeded that observed in monocultures. Cedrela showed an opposite trend with larger trees in monocultures than in mixtures showing the effect of suppression in mixtures. At age 2.0 years monocultures had almost reached their maximum LAI values. Approximate LAI values were 4.5 for Hyeronima and 2.0 for the other two monocultures. LAI of the mixtures increased from 2.0 at age 1.5 years to 4.0 at age 3.5. At the end of this study a two-stratum canopy had developed in mixed-species stands with the shade-intolerant Cordia above both the gap-dependent Hyeronima and the suppressed Cerela. Thus, Cordia and Hyeronima showed compatible height growth and crown structural characteristics in mixtures. The growth patterns of mixed stands suggests that both inter-specific competition with neighboring trees and infections by shoot-boring larvae of a lepidopteran species are responsible for the suppression of Cedrela.

The federal-listed bog turtle (Clemmys muhlenbergii) is the smallest and rarest freshwater turtle species in North America. I studied bog turtles in New England from 1994–1997, examining habitat use and seasonal movements, breeding ecology, demographic characteristics and population viability. I made 1,553 captures, marked 75 adults and radiotracked 50 bog turtles. Home range sizes (0.06–2.79 ha) were similar to other studies; there were no detectable differences between sexes, although males and females used different habitats among seasons. Size of female at sexual maturity (plastral length = 74 mm) was based on reproduction instead of secondary sex characteristics. Clutch size ranged from 2–6 eggs (x¯ = 3.5), with individual variation among years. Incubation (74–103 days) was longer for Massachusetts sites compared to southern nests, and both hatchlings and adults were smaller in body size compared to southern populations. I modeled a stable population with estimated survival rates of 0.32 for hatchlings, 0.97 for adult females, size and age at sexual maturity of PL = 74 mm and 12 y, respectively, and a derived juvenile survival rate of 0.83 (assuming λ = 1.00). The cooler climate and shorter breeding season may place additional constraints on northern populations of bog turtles. These environmental factors may result in slower growth rates, delayed sexual maturation, smaller adult body sizes, iteroparity, and lower nest temperatures resulting in longer incubations of fewer and smaller hatchlings than those in the south. While biologists cannot manage for climate, we can implement protection of this threatened species by identifying and protecting important habitats for hibernation and nesting, preventing hydrologic changes to the system, maintaining open canopy cover, and reducing direct human and animal impacts on adults through monitoring and active management strategies. I suggest the best strategies for bog turtle conservation involve identification and protection of habitats occupied by reproducing populations rather than captive breeding and translocation.

Increases in numbers of Herring (L. argentatus) and Great Black-backed (L. marinus) gulls, and concurrent decreases in numbers of other beach-nesting birds, led to the proposed use of avicides to control gulls on Monomoy NWR, Chatham, Massachusetts. The purpose of this study was to obtain biological information on Monomoy's gull populations, and to use this information to develop and evaluate gull control strategies. Landfill use differed between species. Herring Gulls used more, and traveled farther to, landfills than did Great Black-backed Gulls. Herring Gulls used fewer landfills during the non-breeding than breeding season. Numbers of Herring Gulls in landfills were significantly related to human populations served by those landfills (r$\sp2$ = 0.63, P = 0.0003), Great Black-backed Gull numbers were not. Although both species consumed refuse and natural foods, more Herring than Great Black-backed gull stomachs contained refuse $(X\sp2$ = 7.88, P $<$ 0.005 in 1988; $X\sp2$ = 13.93, P $<$ 0.0002 in 1989). Refuse was a minor dietary component for both species' chicks. The passage of large gulls over nest sites had little impact on Monomoy's Common Tern (Sterna hirundo) and Laughing Gull (L. atricilla) colonies. Few fly-overs (49, 0.04%) at altitudes of 20 m or less resulted in mobbings or disturbances. Terns mobbed large gulls more often than did Laughing Gulls (G = 16.61, P $<$ 0.005), but numbers of birds per mobbing did not differ between species (t = 0.95, P $>$ 0.05). Both species habituated to fly-overs and ignored most large gulls. We developed a deterministic simulation model to identify the effects of different types and levels of control on gull population dynamics. Effectiveness of gull control varied with technique, but no method completely eliminated Herring or Great Black-backed gulls. Model construction and interpretation of outputs are described.

On Georges Bank, skates (F. Rajidae) appear to be replacing depleted populations of economically-important demersal fishes like Atlantic cod (Gadus morhua) and yellowtail flounder (Pleuronectes ferrugineus). Because skates share some food resources with these teleosts, National Marine Fisheries Service biologists are concerned that food resources historically available to demersal fishes are now being consumed by the abundant skates, which could indirectly and negatively impact the growth of demersal species. The main objectives of this study were to estimate the consumptive impact of little skate (Raja erinacea) and winter skate (Raja ocellata) on their invertebrate prey, and to test whether these skates may indirectly impact the growth of yellowtail flounder on Georges Bank. The diet of little skate was comprised mainly of amphipods and decapods on Georges Bank. Both proportions of the two taxa and selection of prey varied depending on season, site, and body length of skates. Seasonal overlap was highest (0.42-0.92) between little skate $<$39 cm and all lengths of yellowtail flounder, indicating little skate could affect yellowtail flounder indirectly through resource competition. The consumptive impact of little skate and winter skate on their benthic prey was determined by estimating the percentage of benthic production consumed by these skate species. Annual consumption ranged from 0.085 kg fish$\sp{-1}$ yr$\sp{-1}$ for little skate 10-19 cm in length to 0.860 kg fish$\sp{-1}$ yr$\sp{-1}$ for skates 50-59 cm, and from 1.186 kg fish$\sp{-1}$ yr$\sp{-1}$ for winter skate 40-49 cm to 5.528 kg fish$\sp{-1}$ yr$\sp{-1}$ for 90-99 cm skates. The percentage of benthic production consumed by little skate and winter skate from 1969 to 1990 ranged from 5% to 15% and 11% to 43%. This indicated only a small to moderate proportion of benthic biomass is consumed by these species. Linear regression and Spearman correlation analyses indicated growth of age 1+ to age 4+ yellowtail flounder was significantly and inversely correlated to its own density, indicating growth of this species is density-dependent. Growth was either not, or positively, correlated to the abundance of skates, groundfishes, and other flounders, suggesting interspecific competition is not an important regulatory mechanism of growth. Therefore, skates appear not to have a measurable impact on the growth dynamics of yellowtail flounder.

<p> In cities, microclimates are created by local mixtures of vegetation, constructed materials, vertical structure, and moisture, with significant consequences for human health, air quality, and resource use. Vegetation can moderate microclimates through evapotranspiration, however this function is dependent on local conditions so its effect may vary over space and time. This dissertation used hyperspectral and thermal remote sensing imagery to derive key observations of urban physical and biophysical properties and model urban microclimates across the megacity of Los Angeles. In Chapter 1, I used Multiple Endmember Spectral Mixture Analysis (MESMA) to map sub-pixel fractions of different vegetation types, as well as other types of urban cover, at 4 m and 18 m resolution over Santa Barbara, California (Wetherley et al., 2017). Fractional estimates correlated with validation fractions at both scales (mean R² = 0.84 at 4 m and R² = 0.76 at 18 m), with accuracy affected by image spatial resolution, endmember spatial resolution, and class spectral (dis)similarity. Accuracy was improved by using endmembers measured at multiple spatial resolutions, likely because they incorporated additional spectral variability that occurred across spatial scales. In Chapter 2, I applied this methodology to derive sub-pixel cover for the greater Los Angeles metropolitan area (4,466 km²) (Wetherley et al., 2018). Further improvement in quantifying sub-pixel vegetation types was achieved by modifying the MESMA shade parameter. Land surface temperature (LST), derived from thermal imagery, was used to model temperature change along vegetation fractional gradients, with slopes of LST change showing significant differences between trees and turfgrass (p &lt; 0.001). Expected per-pixel LST was derived from these gradients based on sub-pixel composition, and when compared to measured LST was found to deviate with a standard deviation of 3.5 &deg;C across the scene. These deviations were negatively related to irrigation and income, while building density was observed to affect tree LST more than it affected turfgrass LST. In Chapter 3, I used the map of Los Angeles landcover, along with data from LiDAR, GIS, and WRF climate variables, to parameterize an urban climate model (Surface Urban Energy and Water Balance Scheme: SUEWS) for 2,123 neighborhoods (each 1 km²) across Los Angeles. Modeled latent fluxes were correlated with remote sensing LST (R² = 0.39) collected over a period of 5 hours, with an overall diurnal pattern modified by irrigation timing. Spatial variability across the study area was related to local landcover, with albedo and vegetation fraction strongly influencing latent and sensible fluxes. A strong regional climatic gradient was observed to affect latent fluxes based on coastal proximity. Overall, this dissertation quantifies the key drivers of urban vegetation function in a large city, and further demonstrates the potential of hyperspectral and thermal imagery for observing city scale surface and microclimate variability.</p><p>

We used the nuclear polyhedrosis virus (LdNPV) of the gypsy moth, Lymantria dispar (Lepidoptera: Lymantriidae), to test a basic assumption of most models of disease dynamics; that the rate of horizontal transmission is directly proportional to the product of the densities of healthy larvae and virus. We made measurements of virus transmission, using small-scale experiments in bags on red oak (Quercus rubra) and black oak (Q. velutina) and observed a decline in the transmission constant as the densities of both healthy larvae and pathogen increased. We hypothesized two possibilities for the non-linearity observed in this system: (1) pathogen inhibition via the effects of induced foliage chemistry and (2) the effect of spatial heterogeneity of LdNPV (pathogen clumping effects). Previous work has linked larval damage on oak foliage to subsequently higher levels of tannins in damaged leaves; and laboratory bioassays have linked higher levels of tannins to a decrease in mortality caused by LdNPV. We damaged LdNPV-contaminated oak foliage using larvae, then bioassayed foliage with test larvae and measured tannins in damaged leaves. None of the experiments showed significant effects of foliage damage on mortality of test larvae or tannin content of damaged leaves, and we concluded that induced foliage responses cannot explain non-linearity of transmission in our previous work, or transmission dynamics in the field. To evaluate the role of pathogen clumping in transmission dynamics, we redefined parameters of the host-parasitoid model of Nicholson and Bailey (1935) for use in the gypsy moth-LdNPV system: a relationship between the assumptions of this model and the continuous time Anderson-May model was described. Using a version of this discrete-time model incorporating spatial heterogeneity, we observed transmission dynamics similar to those in field experiments. To evaluate safety issues in use of genetically altered baculoviruses as insecticides, we field-tested LdNPV that had been genetically-engineered for non- persistence. The EV was released in a forest setting, and did not persist or spread past the first year of release. Concerns regarding movement of baculoviruses were also addressed in experiments exploring the action of rainfall on the translocation of LdNPV.

O presente trabalho foi desenvolvido em áreas florestais naturais e implantadas de Florestas Estacionais Semideciduais remanescentes do planalto paulista com o objetivo de estudar a periodic idade de crescimento, fenologia e atividade cambial. A pesquisa visa determinar a idade e o crescimento de 23 espécies arbóreas tropicais e subtropicais, contribuindo, desta forma, com a aquisição de conhecimentos científicos básicos sobre a biologia e a ecologia do crescimento das mesmas. A compreensão da dinâmica das populações florestais e o comportamento de crescimento das suas espécies foram obtidos a partir do acompanhamento mensal da periodicidade de crescimento através da implantação de faixas dendrométricas permanentes nos troncos das árvores e observações dos estágios fenológicos (folhas, brotamento, floração e frutificação), avaliados mensalmente durante o período de janeiro de 2000 a outubro de 2001 em relação às variações climáticas. A determinação da idade e taxa de crescimento das árvores foram obtidas através da contagem e mensuração da largura dos anéis de crescimento a partir de "baguetas" coletadas com auxílio da sonda de Pressler, na altura do DAP. Os resultados deste trabalho permitiram concluir que as variações das taxas de crescimento em circunferência do tronco das árvores estão estreitamente relacionadas à precipitação e a disponibilidade de água no solo na estação chuvosa e a ocorrência de um período de seca com redução e/ou cessação da atividade cambial. Da mesma forma, os estágios fenológicos estão relacionados com fatores abióticos como o clima e, em especial, às variações de precipitação entre as estações seca e úmida. As informações sobre a influência de fatores ambientais na taxa de crescimento das espécies arbóreas permitirão a adoção de medidas científicas que visem a preservação da biodiversidade desses ecossistemas frágeis e constantemente ameaçados. / This paper was developed in natural and implanted forest areas of remaining Semidecidual Stately Forests in Sao Paulo plains, with the aim of stud ying the periodicity of growth, the phenology and its changing activity. The research seeks determining the age and growth of 23 tropical and semitropical arboreal species, thus contributing with the gathering of basic scientific knowledge on the biology and the ecology of their growth. The understanding on the forests’ populations’ dynamics and the behavior of their growth were obtained with a monthly observation through the inserting of permanent dendometric strips into the trees trunks and through the phonological stages analysis (leaves, sprouting, blooming and fruiting), evaluated from January 2000 to October 2001 because of the weather variations. The age and growth rate determination was obtained counting and measuring the growth rings starting with wood samples collected with the help of a Pressler probe, at the DAP height. The results of this paper led to the conclusion that the variations on the perimeter of the trunk growth rate are closely related to the rainfall and water availability in the soil under the rainy season and the occurrence of a drought period with reduction and/or changing activity cessation. Likewise, the phenological stages are related to abiotic factors like weather and, especially, to rainfall variations between the dry and humid seasons. The information on the influence of environmental factors on the growth rate of arboreal species will facilitate the adoption of scientific measures seeking the preservation of the biodiversity of these ecosystems so fragile and constantly under threat

O presente trabalho foi desenvolvido em áreas florestais naturais e implantadas de Florestas Estacionais Semideciduais remanescentes do planalto paulista com o objetivo de estudar a periodic idade de crescimento, fenologia e atividade cambial. A pesquisa visa determinar a idade e o crescimento de 23 espécies arbóreas tropicais e subtropicais, contribuindo, desta forma, com a aquisição de conhecimentos científicos básicos sobre a biologia e a ecologia do crescimento das mesmas. A compreensão da dinâmica das populações florestais e o comportamento de crescimento das suas espécies foram obtidos a partir do acompanhamento mensal da periodicidade de crescimento através da implantação de faixas dendrométricas permanentes nos troncos das árvores e observações dos estágios fenológicos (folhas, brotamento, floração e frutificação), avaliados mensalmente durante o período de janeiro de 2000 a outubro de 2001 em relação às variações climáticas. A determinação da idade e taxa de crescimento das árvores foram obtidas através da contagem e mensuração da largura dos anéis de crescimento a partir de “baguetas” coletadas com auxílio da sonda de Pressler, na altura do DAP. Os resultados deste trabalho permitiram concluir que as variações das taxas de crescimento em circunferência do tronco das árvores estão estreitamente relacionadas à precipitação e a disponibilidade de água no solo na estação chuvosa e a ocorrência de um período de seca com redução e/ou cessação da atividade cambial. Da mesma forma, os estágios fenológicos estão relacionados com fatores abióticos como o clima e, em especial, às variações de precipitação entre as estações seca e úmida. As informações sobre a influência de fatores ambientais na taxa de crescimento das espécies arbóreas permitirão a adoção de medidas científicas que visem a preservação da biodiversidade desses ecossistemas frágeis e constantemente ameaçados. / This paper was developed in natural and implanted forest areas of remaining Semidecidual Stately Forests in Sao Paulo plains, with the aim of stud ying the periodicity of growth, the phenology and its changing activity. The research seeks determining the age and growth of 23 tropical and semitropical arboreal species, thus contributing with the gathering of basic scientific knowledge on the biology and the ecology of their growth. The understanding on the forests’ populations’ dynamics and the behavior of their growth were obtained with a monthly observation through the inserting of permanent dendometric strips into the trees trunks and through the phonological stages analysis (leaves, sprouting, blooming and fruiting), evaluated from January 2000 to October 2001 because of the weather variations. The age and growth rate determination was obtained counting and measuring the growth rings starting with wood samples collected with the help of a Pressler probe, at the DAP height. The results of this paper led to the conclusion that the variations on the perimeter of the trunk growth rate are closely related to the rainfall and water availability in the soil under the rainy season and the occurrence of a drought period with reduction and/or changing activity cessation. Likewise, the phenological stages are related to abiotic factors like weather and, especially, to rainfall variations between the dry and humid seasons. The information on the influence of environmental factors on the growth rate of arboreal species will facilitate the adoption of scientific measures seeking the preservation of the biodiversity of these ecosystems so fragile and constantly under threat