Henslow’s sparrow (Ammodramus henslowii) winters in recently burned sites in pine savannas of the Southeastern United States. Previous studies have suggested that factors such as seed abundance and litter depth are important to wintering Henslow’s sparrows. My study asked how habitat variables including vegetation structure, seed abundance, and arthropod abundance predict Henslow’s sparrow site occupancy at Mississippi Sandhill Crane National Wildlife Refuge. In this study, Henslow’s sparrow more often occupied sites burned one growing season earlier than sites burned two growing seasons earlier, and did not occupy sites burned three or more growing seasons earlier. Data indicated that mass of graminoid seeds borne on stalks in November and minimum total seed mass were higher in occupied sites vs. unoccupied sites while litter density was lower. This suggests that Henslow’s sparrow selects habitats that may maximize foraging efficiency and probability of survival based on information about litter density and seed availability.

Considerando a importância da ciclagem de nutrientes como indicador na manutenção da produtividade do ecossistema, o presente estudo teve como objetivo avaliar a dinâmica sazonal de produção e taxa de decomposição de serapilheira em um fragmento de Cerrado sensu stricto. Para avaliação de aporte de serapilheira foram utilizados 50 coletores circulares com 112,8 cm de diâmetro, distribuídos sistematicamente. As coletas de serapilheira foram realizadas mensalmente de junho de 2016 a maio 2017 e o material coletado foi acondicionado em sacos plásticos, posteriormente levados para o laboratório onde foi realizada a separação nas frações folhas, galhos e material reprodutivo. Posteriormente, o material foi embalado em sacos de papel e levado à estufa à temperatura de 70 oC, para a determinação do peso seco. A decomposição da serapilheira foi avaliada utilizando-se o método de litter bags, com distribuição aleatória de 288 litter bags que continham 20 gramas de folhas e 24 litter bags que continham 20 gramas de galhos. A produção anual de serapilheira foi quantificada em 6.042,50 kg.ha-1.a-1, em que a fração foliar foi predominante apresentando uma produção de 4.644,40 kg.ha-1.a-1, seguida da fração galhos (1.084,10 kg.ha-1.a-1) e material reprodutivo (329,90 kg.ha-1.a-1). A produção de serapilheira obteve maior produção no mês de julho com 1.464,00 kg.ha-1 e menor produção no mês de dezembro (138,70 kg.ha-1). Foi observada correlação negativa significativa entre a produção de serapilheira e suas frações com a precipitação pluviométrica e umidade relativa do ar. A decomposição da massa foliar atingiu 49% e a de galhos 50%, durante o período de nove meses, em que a constante de decomposição (k) para massa foliar e para galhos foi de 0,0030 g g-1dia-1. Por esta constante, a estimativa para o desaparecimento de massa total foi estimada em 1.000 dias (29 meses). É possível concluir que a produção de serapilheira apresentou sazonalidade bem marcada, com maior produção durante a época seca e menor na época chuvosa, com forte influência de precipitação e umidade relativa do ar na deposição das folhas. A decomposição se mostrou lenta tanto para folhas como para galhos obtendo assim o valor da constante de decomposição 0,0030 g g-1dia-1 para ambos. / Considering the importance of nutrient cycling as an indicator in the maintenance of the productivity of the ecosystem, the present study aimed to assess the seasonal dynamics of production and decomposition rate of litter in a fragment of Cerrado sensu stricto. For evaluation of supply of burlap were used 50 circular collectors with 112.8 cm diameter, distributed systematically. Litter collections were performed monthly June 2016-may 2017 and the collected material was packed in plastic bags, then taken to the laboratory where the separation was carried out in fractions leaves, twigs and reproductive material. After that, the material was packed in paper bags and washed the greenhouse at the 70 C, for the determination of the dry weight. The decomposition of leaf litter was evaluated using the method of litter bags, with random distribution of 288 litter bags containing 20 grams of leaves and 24 litter bags containing 20 grams of branches. The annual production of litterfall was quantified in 6.042,50 kg. ha-1. yr- 1, in which the leaf was prevalent fraction presented a production of 4.644,40 kg. ha-1. yr-1, then the fractions branches (1.084,10 kg. ha-1. yr-1) and reproductive material (329,90 kg. ha-1. yr-1). The litterfall obtained higher production in July with 1.464,00 kg. ha-1 and lower production in the month of December (138,70 kg. ha-1). A significant negative correlation was observed between litterfall and its fractions with the precipitation and relative humidity. The decomposition of foliar mass reached 49% and 50% of twigs during the nine-month period, in which the decomposition constant (k) for leaf mass and for branches was 0.0030 g g-1-1day.For this constant, the estimate for the disappearance of total mass has been estimated to be 1.000 days (29 months). It can be concluded that the litterfall presented seasonality well marked, with higher output during the dry season and lower in the rainy season with strong influence of precipitation and relative humidity in the deposition of the leaves. The breakdown proved slow for both leaves as for branches to get the value of the constant of decomposition 0.0030 g g-1-1 day for both.

This research considers human impacts on three components of biodiversity (composition, spatial structure and function). Given the relict character and unusual biogeochemical balance of tropical montane cloud forests in Mexico, logging poses a pressing threat to their survival. Specifically, this thesis explores the effect of selective logging and above-ground secondary succession on the biogeochemical cycling and soil macroinvertebrate community in a cloud forest in Oaxaca, Mexico. The research investigates: (1) whether the above-ground chain of successional changes in tree dominance, litterfall, litter diversity and soil microenvironmental conditions are coupled with a below-ground succession of soil nutrient availability and macroinvertebrate communities, (2) the role of spatial structuring of environmental conditions and litter resources as determinates of the nutrient availability and macroinvertebrate taxa abundance, (3) the implications of successional changes for decomposition and (4) whether the local influence of single trees explains the spatial structure of macroinvertebrate communities in late successional forests. The work was carried out in three chronosequences (c.15, 45, 75 and 100 year-old stages) of high altitude (1500-2000m) tropical montane cloud forest, two recently logged sites and two pristine sites. the macroinvertebrates in the litter and mineral soil were hand sorted from monoliths. Parametric statistics and canonical correspondance analysis were used to determine mean successional trends, and Spatial Analysis by Distance Indices and geostatistical methods were used in combination to determine spatial patterns. Two decompositional experiments were performed to explore the relationship between decompositional rate, litter quality and macroinvertebrate community higher taxa composition in different successional stages and under the canopy of different tree species. The research showed that: 1. The macroinvertebrate community composition in both recently logged sites and pristine forests were distinct compared to secondary successional stages. A decrease in soil temperature and nutrient availablity but increase in litter diversity and soil organic matter recorded through succession were accompanied by an increase in the number of macroinvertebrate taxa in the soil. For exampl, Collembola were most abundant in recently logged sites and earthworms (Megascolecidae) were almost excluvely found in pristine forests. 2. The oldest secondary forest (100 year-old) showed the highest frequency of aggregation in the abundance of individual macroinvertebrate taxa, and the highest and most uniform value of Shannon's diversity. This suggests that high levels of diversity in litter resources and soil chemistry in late succession are associated with complex spatial structuring of highly diverse macroinvertebrate communities. 3. The leaves of a late successional species (Persea americana)decomposed at a slightly slower rate than an early successional species (Pinus chiapensis) in all successional stages, yet the number and Shannon's diversity of macroinvertebrate taxa that invaded decomposing P.Americana leaves was consistently higher. The preference of macroinvertebrate taxa for the late-successional leaves was ultimately explained by differences in leaf quality during decomposition. P.americana leaves had higher concentrations of cations throughout decomposition and their concentration of lignin and nitrogen became higher. 4. In the 100-year-old forest, the effect of seasonal variation on soil microenvironmental conditions and litter availability was different under the canopy of different tree species. Furthermore, the chemical evolution of the same leaf type (e.g. Oreopanax xalapensis) was differentwhen decomposing under different canopies. The highly diverse and spatially complex macroinvertebrate community found in late succession (and experimental litter) was largely explained by the interactive effects of seasonal variation, tree species, litter quality and availability of the decomposing leaf type. The results provide the first analysis of the relationship between soil biodiversity and the tight biogeochemical cycling in this relict ecosystem type. Overall the results indicate that mature cloud forests sustain a diverse and spatially heterogenous macroinvertebrate community. The compositional and spatial components of soil biodiversity are compromised by logging and full recovery may take mopre than 100 years.

Includes bibliographical references

Graduation date: 2003

Introduction: According to the CDC (2008), tobacco-related deaths out number deaths from alcohol use, motor vehicle injuries, suicides, murders, human immunodeficiency virus (HIV), and illegal drug use. One out of every five deaths in the United States can be attributed to tobacco, culminating in a staggering 443,000 deaths in the US every year. Smoking is also the leading preventable cause of death in America (CDC, 2008). In 2006, the Surgeon General’s Report speaks to not only the detrimental effects of smoking, but also the harmful effects second hand smoke can have on an individual’s health. Furthermore, the Centers for Disease Control’s Office of Smoking and Health reported that 49,400 deaths every year in the US are the result of second hand smoke exposure, of which 46,000 will have died from heart disease attributable to second hand smoke in the environment in which they live, work, play, and learn (CDC, 2008). While the negative health outcomes with tobacco use have inundated mainstream media and literature, tobacco use has another large and devastating effect on communities around the world. That effect is the result of Tobacco Product Litter (TPL). Beyond the unsightliness of TPL, several other unwanted complications to society result from the disregarded refuse, such as harm to the environment and damages incurred by other businesses not associated at all with tobacco products. Rationale for Intervention: First and foremost the Tobacco-Free GSU Initiative was intended to promote the health of the Georgia State University community consisting of students, faculty, and staff. The American College Health Association (2009) recommends 100% tobacco-free campuses, indoors and outdoors. Studies have shown that non-smokers and smokers attending college are in favor of campus policies that control the use of tobacco on campus (Rigotti, Regan, Moran, et al., 2003; Thompson B, Coronado GD, Chen L, et al., 2006). Sawdey et al. (2011) cites the need for the implementation of smoke-free policies by campuses in order to utilize the opportunity to create an atmosphere conducive to tobacco cessation. Considering that one third of young Americans attend a college or university (Rigotti et al., 2003), exposing one third of the youth population of the United States to a tobacco-free environment could potentially change the socially acceptable norms of using tobacco, whist simultaneously creating an environment free of TPL. Intervention Strategy Analysis: Tobacco-Free GSU utilized a methodology similar to the strategies Glassman, Reindel and Whewell outlined in their 2011 study Strategies for Implementing a Tobacco-Free Campus. The Glassman et al. (2011) strategy included: Creating a Committee, Utilizing a Student Debate, Publicity, Drafting of a Potential Policy, Targeting the College or University Board of Trustees, Addressing Barriers to Becoming Tobacco-Free, Student Involvement, Administrative and Staff Support, Resources, and Enforcement Conclusion: In order to facilitate the best possible outcome, this author recommends those seeking to create a tobacco-free campus utilize the strategies outlined throughout this document, whilst creating strategies specific to their location, population, and situation.

Introduction: According to the CDC (2008), tobacco-related deaths out number deaths from alcohol use, motor vehicle injuries, suicides, murders, human immunodeficiency virus (HIV), and illegal drug use. One out of every five deaths in the United States can be attributed to tobacco, culminating in a staggering 443,000 deaths in the US every year. Smoking is also the leading preventable cause of death in America (CDC, 2008). In 2006, the Surgeon General’s Report speaks to not only the detrimental effects of smoking, but also the harmful effects second hand smoke can have on an individual’s health. Furthermore, the Centers for Disease Control’s Office of Smoking and Health reported that 49,400 deaths every year in the US are the result of second hand smoke exposure, of which 46,000 will have died from heart disease attributable to second hand smoke in the environment in which they live, work, play, and learn (CDC, 2008). While the negative health outcomes with tobacco use have inundated mainstream media and literature, tobacco use has another large and devastating effect on communities around the world. That effect is the result of Tobacco Product Litter (TPL). Beyond the unsightliness of TPL, several other unwanted complications to society result from the disregarded refuse, such as harm to the environment and damages incurred by other businesses not associated at all with tobacco products. Rationale for Intervention: First and foremost the Tobacco-Free GSU Initiative was intended to promote the health of the Georgia State University community consisting of students, faculty, and staff. The American College Health Association (2009) recommends 100% tobacco-free campuses, indoors and outdoors. Studies have shown that non-smokers and smokers attending college are in favor of campus policies that control the use of tobacco on campus (Rigotti, Regan, Moran, et al., 2003; Thompson B, Coronado GD, Chen L, et al., 2006). Sawdey et al. (2011) cites the need for the implementation of smoke-free policies by campuses in order to utilize the opportunity to create an atmosphere conducive to tobacco cessation. Considering that one third of young Americans attend a college or university (Rigotti et al., 2003), exposing one third of the youth population of the United States to a tobacco-free environment could potentially change the socially acceptable norms of using tobacco, whist simultaneously creating an environment free of TPL. Intervention Strategy Analysis: Tobacco-Free GSU utilized a methodology similar to the strategies Glassman, Reindel and Whewell outlined in their 2011 study Strategies for Implementing a Tobacco-Free Campus. The Glassman et al. (2011) strategy included: Creating a Committee, Utilizing a Student Debate, Publicity, Drafting of a Potential Policy, Targeting the College or University Board of Trustees, Addressing Barriers to Becoming Tobacco-Free, Student Involvement, Administrative and Staff Support, Resources, and Enforcement Conclusion: In order to facilitate the best possible outcome, we recommend those seeking to create a tobacco-free campus utilize the strategies outlined throughout this document, whilst creating strategies specific to their location, population, and situation.

We collected the data for decomposition of spruce litter to determine the limit values of mass loss and to find both chemical and climate factors that influence limit values. Our data contained 28 sequences of spruce which mainly in Sweden and a small part in other places. We choose mean annual temperature (MAT) and mean annual precipitation (MAP) as climate factors and water solubles, lignin, N, P, K, Ca, Mg and Mn as chemical factors. Then we got the estimated limit values by performing a nonlinear model with mass loss and time spots, and found out the influential factors by using another linear mixed model. At the end we knew that linear mixed model is a proper and efficient approach for determining the factors, P and MAP are the significant factors and Species is a good random effect to explain the variance within groups.

Thesis (Ph. D.)--University of Washington, 2002. / Vita. Includes bibliographical references (leaves 148-163).

Headwaters, which are the most common stream order in the landscape, are mostly dependent on energy produced in the terrestrial system, largely consisting of leaf litter from riparian vegetation. The aim of this study was to investigate the decomposition in headwaters of leaf litter from three native (alder, birch, spruce) and one non-native (lodgepole pine) species and how decomposition responds to changes in the environment. Further, microbial and shredder influences on leaf-litter decomposition and aquatic decomposer ability to adapt to non-native species was investigated. By using field-data from this study, calculations were made to assess if microbes and shredders are resource limited. Litterbags were placed in 20 headwater streams in northern Sweden that varied in water chemistry, stream physical characteristics and riparian vegetation. The results revealed that species litter decomposition of different plant species was affected differently by changes in environmental variables. Alder and birch decomposition were positively associated, whereas lodgepole pine deviated from the other species in decomposition and its relationship with important environmental variables, indicating that the ability of the boreal aquatic systems to decompose litter differs between introduced and native species. When including macroinvertebrates, shredder fragmentation generally increased decomposition, but was not significant for all sites. Resource availability for microbes and shredders was controlled by litter input, and no risk of resource limitations was evident during the study period. These findings highlight a complexity of the decomposition process that needs to be considered when predicting changes due to human activities.