Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 27 for “"Terrestrial ecosystem"”.
-
Modeling of N2O emission from unmanaged terrestrial ecosystem soils
… (ISAM), to model the global N2O emissions from terrestrial ecosystem soils. The model is calibrated and evaluated with field measurements of N2O from different sites with different biome types, climate conditions, and soil properties. The model is able to capture the temporal trends and …
-
Investigating the Influence of Interannual Precipitation Variability on Terrestrial Ecosystem Productivity
… precipitation variability on above-ground terrestrial ecosystem productivity in the Hulunbuir ecosystem, using time series analysis, regression analysis, and machine learning models. The study's primary goal was to enhance our understanding of the effects of precipitation variability on …
-
Quantifying terrestrial ecosystem carbon dynamics with mechanistically-based biogeochemistry models and in situ and remotely sensed data
<p>Terrestrial ecosystem plays a critical role in the global carbon cycle and climate system. Therefore, it is important to accurately quantify the carbon dynamics of terrestrial ecosystem under future climatic change condition. This dissertation evaluates the regional carbon dynamics by using …
-
Patterns of energy flow in populations of the dominant insect consumers on Marion Island
… primary consumers or decomposers in the terrestrial ecosystem of sub-Antarctic Marion Island. Patterns of energy flow in individuals ("life strategies") and populations (population energetics) of the five species were studied against the evolutionary templet of their respective …
-
Quantifying mercury surface fluxes by combining atmospheric observations and models
… the ocean contributes about a half. The global terrestrial ecosystem is found to be neither a net source nor a net sink of Hg⁰ (gaseous elemental mercury). The optimized Asian anthropogenic emissions (0.7-1.8 Gg yr-¹) are very likely higher than bottom-up estimates, implying missing sources, …
-
Influence of climate and the expansion of C4 grasses on sequence-scale cyclicity and landscape development during the late Miocene to Pleistocene of West Texas.
… records a period of global climate change and terrestrial ecosystem evolution; however, little is known about whether these changes influenced sedimentary and soil forming processes. The late Miocene to Pleistocene Fort Hancock and Camp Rice Formations from two adjacent isolated basins, …
-
Modeling the combined environmental effects on net land carbon flux in the present and future scenarios
… dioxide (CO2) in the global carbon cycle. The terrestrial ecosystem globally absorbs about 30% of the anthropogenic CO2 emissions as a sink. Land therefore consists of two counteracting CO2 fluxes, a source from LULCC and a sink from the terrestrial ecosystem. This net land carbon flux (e.g., …
-
An Organic Energy Budget for the New York State Barge Canal
… order man-made waterway in western New York. The ecosystem approach, in which all input and output of energy as organic matter are measured, is used to describe the energy flow in an 1130-meter segment of the canal. The annual input of energy to the system is 38.1 x 109 kcal/m2. Over 99% of this …
-
Towards a paradigm shift in the modeling of soil organic carbon decomposition for earth system models
<p>Soils are the largest terrestrial carbon pools and contain approximately 2200 Pg of carbon. Thus, the dynamics of soil carbon plays an important role in the global carbon cycle and climate system. Earth System Models are used to project future interactions between terrestrial ecosystem carbon …
-
Uncertainty quantification and calibration of physical models
<p>An ecosystem model is a representation of a real complex ecological system, and is usually described by sophisticated mathematical models. Terrestrial Ecosystem Model (TEM) is one of the ecosystem models, that describes the dynamics of car- bon, nitrogen, water and other vegetation related …
-
The economic impact of global climate and tropospheric oxone on world agricultural production
… world economy and crop yield results from the Terrestrial Ecosystem Model (TEM), a biogeochemical model of terrestrial vegetation. I disaggregated the original EPPA model to capture the dynamic behaviors of crops, livestock and forestry within the agriculture sector. Further calibration was …
-
Characterization of dissolved fluvial carbon from landscape characteristics across High Arctic headwater streams
… is an important conduit of carbon from the terrestrial ecosystem to the Arctic Ocean, where fluvial carbon is a product of both the source and pathway of the stream network through a watershed. Small headwater streams in the High Arctic are understudied and account for a significant amount …
-
Impacts of greenhouse gas mitigation policies on agricultural land
… S. Marine Biological Laboratory (MBL) apply the Terrestrial Ecosystem Model (TEM) to simulate land productivities. Based on the predictions of land characteristics affecting land-use decisions, I develop an econometric model to predict the land use affected by climate, GHGs, and tropospheric …
-
Root Dynamics, Management Effects and Carbon Sequestration on Invaded and Native Semi-Arid Grasslands
Root dynamics are a major component of terrestrial ecosystem processes but they have not been broadly studied, due to the difficulty of quantifying root production and mortality. The use of minirhizotrons facilitates belowground research, but sample intervals are controversial since long intervals …
-
Soil microbial function in a time of global change: effect of dairy antibiotics on soil microbial communities and ecosystem function
… potential to disturb microbial communities and ecosystem functions they regulate is under appreciated. Antibiotics are commonly used in the livestock sector, accounting for 80% of antibiotic use domestically. This dissertation addresses three facets of this problem. Chapter 2 is a nation-wide …
-
Environmental Controls on Foliar Respiration in Arctic Plants
… phenomena and its inclusion in regional terrestrial ecosystem carbon models. Also, foliar carbon fluxes in woody shrub species are significantly higher than non-shrub species across experiments, a finding that demands attention given the general trend of increasing shrub cover associated …
-
Activity of methanogenic archaea under simulated Mars analog conditions
… the potential of life to exist in possible extraterrestrial habitats on our neighboring planet. In this thesis methanogenic archaea originating from two extreme environments on Earth were investigated to test their ability to be active under simulated Mars analog conditions. These extreme …
-
Exotic Species Invasion and Biodiversity in Bangladesh Forest Ecosystems
… drivers are two major issues in tropical forest ecosystems. This dissertation deals with these two issues in a tropical forest ecosystem in Bangladesh. Considering the first issue, it comprises two manuscripts: a systematic review and a field survey in Bangladesh forest ecosystem. The review was …
-
EFFECTS OF TIME, SEED SOURCE, AND PLANT COMPOSITION ON MACROINVERTEBRATES IN RESTORED PRAIRIE
… primary productivity and nutrient cycling in ecosystems. They are also important links between producer and higher trophic levels. Despite their important role in terrestrial ecosystem function, invertebrates are frequently overlooked in ecological restorations. Thus, the objective of this …
Page 1 of 2