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Full-Text Articles in Life Sciences

An Evaluation Of Soils On Sólheimajökull Glacier Foreland: Using Invertebrates And Decomposition As Bio-Indicators Of Soil Quality, Carolyn Weisman Oct 2019

An Evaluation Of Soils On Sólheimajökull Glacier Foreland: Using Invertebrates And Decomposition As Bio-Indicators Of Soil Quality, Carolyn Weisman

Independent Study Project (ISP) Collection

Anthropogenic climate change has led to the retreat of glaciers globally. As glaciers melt, they expose the underlying land- termed the glacier foreland. These forelands provide a natural laboratory for studying ecological succession after a massive disturbance, which is in this case glaciation. In this study, soil invertebrates and decomposition are used as bio-indicators of the soil quality in the foreland of Sólheimajökull Outlet Glacier. Soil cores were collected from five sites (A-E) located 300m apart moving away from the glacier terminus. The abundance of each observed invertebrate taxa and the dissolved oxygen (DO) levels were taken for 30 soil …


The Stability Of Temperate Lakes Under The Changing Climate, Aleksey Paltsev Sep 2019

The Stability Of Temperate Lakes Under The Changing Climate, Aleksey Paltsev

Electronic Thesis and Dissertation Repository

There is a collective prediction among ecologists that climate change will enhance phytoplankton biomass in temperate lakes. Yet there is noteworthy variation in the structure and regulating functions of lakes to make this statement challengeable and, perhaps, inaccurate. To generate a common understanding on the trophic transition of lakes, I examined the interactive effects of climate change and landscape properties on phytoplankton biomass in 12,644 lakes located in relatively intact forested landscapes. Chlorophyll-a (Chl-a) concentration was used as a proxy for phytoplankton biomass. Chl-a concentration was obtained via analyzing Landsat satellite imagery data over a 28-year period (1984-2011) and using …


Enhanced Acidification Of Global Coral Reefs Driven By Regional Biogeochemical Feedbacks, Tyler Cyronak, Kai G. Schulz, Isaac R. Santos, Bradley D. Eyre Sep 2019

Enhanced Acidification Of Global Coral Reefs Driven By Regional Biogeochemical Feedbacks, Tyler Cyronak, Kai G. Schulz, Isaac R. Santos, Bradley D. Eyre

Tyler Cyronak

Physical uptake of anthropogenic CO2 is the dominant driver of ocean acidification (OA) in the open ocean. Due to expected decreases in calcification and increased dissolution of CaCO3 framework, coral reefs are thought to be highly susceptible to OA. However, biogeochemical processes can influence the pCO2 and pH of coastal ecosystems on diel and seasonal time scales, potentially modifying the long‐term effects of increasing atmospheric CO2. By compiling data from the literature and removing the effects of short‐term variability, we show that the average pCO2 of coral reefs throughout the globe has increased ~3.5‐fold …


Marine Invertebrates: Communities At Risk, Jennifer A. Mather Aug 2019

Marine Invertebrates: Communities At Risk, Jennifer A. Mather

Jennifer Mather, PhD

Our definition of the word ‘animal’ centers on vertebrates, yet 99% of the animals on the planet are invertebrates, about which we know little. In addition, although the Census of Marine Life (COML.org) has recently conducted an extensive audit of marine ecosystems, we still do not understand much about the animals of the seas. Surveys of the best-known ecosystems, in which invertebrate populations often play a key role, show that the invertebrate populations are affected by human impact. Coral animals are the foundation of coral reef systems, which are estimated to contain 30% of the species in the ocean. Physical …


Climate Change Impacts On Winter Wheat Yield In Northern China, Xiu Geng, Fang Wang, Wei Ren, Zhixin Hao Jun 2019

Climate Change Impacts On Winter Wheat Yield In Northern China, Xiu Geng, Fang Wang, Wei Ren, Zhixin Hao

Plant and Soil Sciences Faculty Publications

Exploring the impacts of climate change on agriculture is one of important topics with respect to climate change. We quantitatively examined the impacts of climate change on winter wheat yield in Northern China using the Cobb–Douglas production function. Utilizing time-series data of agricultural production and meteorological observations from 1981 to 2016, the impacts of climatic factors on wheat production were assessed. It was found that the contribution of climatic factors to winter wheat yield per unit area (WYPA) was 0.762–1.921% in absolute terms. Growing season average temperature (GSAT) had a negative impact on WYPA for the period of 1981–2016. A …


Assessment Of Agricultural Drought Considering The Hydrological Cycle And Crop Phenology In The Korean Peninsula, Chul-Hee Lim, Seung Hee Kim, Jong Ahn Chun, Menas Kafatos, Woo-Kyun Lee May 2019

Assessment Of Agricultural Drought Considering The Hydrological Cycle And Crop Phenology In The Korean Peninsula, Chul-Hee Lim, Seung Hee Kim, Jong Ahn Chun, Menas Kafatos, Woo-Kyun Lee

Mathematics, Physics, and Computer Science Faculty Articles and Research

Hydrological changes attributable to global warming increase the severity and frequency of droughts, which in turn affect agriculture. Hence, we proposed the Standardized Agricultural Drought Index (SADI), which is a new drought index specialized for agriculture and crops, and evaluated current and expected droughts in the Korean Peninsula. The SADI applies crop phenology to the hydrological cycle, which is a basic element that assesses drought. The SADI of rice and maize was calculated using representative hydrological variables (precipitation, evapotranspiration, and runoff) of the crop growing season. In order to evaluate the effectiveness of SADI, the three-month Standardized Precipitation Index, which …


Fallen Pillars: The Past, Present, And Future Population Dynamics Of A Rare, Specialist Coral–Algal Symbiosis, Andrea Chan, Cynthia L. Lewis, Karen L. Neely, Iliana B. Baums May 2019

Fallen Pillars: The Past, Present, And Future Population Dynamics Of A Rare, Specialist Coral–Algal Symbiosis, Andrea Chan, Cynthia L. Lewis, Karen L. Neely, Iliana B. Baums

Marine & Environmental Sciences Faculty Articles

With ongoing changes in climate, rare and ecologically specialized species are at increased risk of extinction. In sessile foundation fauna that reproduce asexually via fragmentation of existing colonies, the number of colonies does not reflect the number of genets and thus can obscure genotypic diversity. Colonies that are the product of fragmentation are not visually distinguishable from colonies that stem from sexual recruits. For this reason, molecular markers are necessary to assess genotypic variation and population structure in clonal organisms such as reef-building corals and their endosymbiotic dinoflagellates. For the rare Caribbean pillar coral, Dendrogyra cylindrus, and its endosymbiotic …


Blacklegged Tick (Ixodes Scapularis) Distribution In Maine, Usa, As Related To Climate Change, White-Tailed Deer, And The Landscape, Susan P. Elias May 2019

Blacklegged Tick (Ixodes Scapularis) Distribution In Maine, Usa, As Related To Climate Change, White-Tailed Deer, And The Landscape, Susan P. Elias

Electronic Theses and Dissertations

Lyme disease is caused by the bacterial spirochete Borrelia burgdorferi, which is transmitted through the bite of an infected blacklegged (deer) tick (Ixodes scapularis). Geographic invasion of I. scapularis in North America has been attributed to causes including 20th century reforestation and suburbanization, burgeoning populations of the white-tailed deer (Odocoileus virginianus) which is the primary reproductive host of I. scapularis, tick-associated non-native plant invasions, and climate change. Maine, USA, is a high Lyme disease incidence state, with a history of increasing I. scapularis abundance and northward range expansion. This thesis addresses the question: “To …


A Comparative Analysis Of Governance And Leadership In Agricultural Development Policy Networks, Jessica Rudnick, Meredith Niles, Mark Lubell, Laura Cramer May 2019

A Comparative Analysis Of Governance And Leadership In Agricultural Development Policy Networks, Jessica Rudnick, Meredith Niles, Mark Lubell, Laura Cramer

College of Agriculture and Life Sciences Faculty Publications

Agricultural development initiatives feature many public and private organizations working together across sectors and scales to pursue the goals of food security and climate resilience. Policy networks are considered a crucial ingredient for the learning and cooperation needed to effectively implement agricultural development projects and increase community resiliency, yet very little comparative empirical data has been collected to assess where and how these networks operate. We contribute to filling this gap by characterizing the governance and leadership patterns within agricultural development policy networks that connect organizations working on climate resilience and food security activities in 14 smallholder farming communities across …


Indirect Legacy Effects Of An Extreme Climatic Event On A Marine Megafaunal Community, Robert Nowicki, Michael Heithaus, Jordan Thompson, Derek Burkholder, Kirk Gastrich, Aaron Wirsing Apr 2019

Indirect Legacy Effects Of An Extreme Climatic Event On A Marine Megafaunal Community, Robert Nowicki, Michael Heithaus, Jordan Thompson, Derek Burkholder, Kirk Gastrich, Aaron Wirsing

Marine & Environmental Sciences Faculty Articles

While extreme climatic events (ECEs) are predicted to become more frequent, reliably predicting their impacts on consumers remains challenging, particularly for large consumers in marine environments. Many studies that do evaluate ECE effects focus primarily on direct effects, though indirect effects can be equally or more important. Here, we investigate the indirect impacts of the 2011 “Ningaloo Niño” marine heatwave ECE on a diverse megafaunal community in Shark Bay, Western Australia. We use an 18‐year community‐level data set before (1998–2010) and after (2012–2015) the heatwave to assess the effects of seagrass loss on the abundance of seven consumer groups: sharks, …


Effects Of Increased Precipitation On The Life History Of Spring- And Autumn-Germinated Plants Of The Cold Desert Annual Erodium Oxyrhynchum (Geraniaceae), Yanfeng Chen, Xiang Shi, Lingwei Zhang, Jerry M. Baskin, Carol C. Baskin, Huiliang Liu, Daoyuan Zhang Apr 2019

Effects Of Increased Precipitation On The Life History Of Spring- And Autumn-Germinated Plants Of The Cold Desert Annual Erodium Oxyrhynchum (Geraniaceae), Yanfeng Chen, Xiang Shi, Lingwei Zhang, Jerry M. Baskin, Carol C. Baskin, Huiliang Liu, Daoyuan Zhang

Biology Faculty Publications

Future increased precipitation in cold desert ecosystems may impact annual/ephemeral plant species that germinate in both spring and autumn. Our primary aim was to compare the life history characteristics of plants from spring-germinating (SG) and autumn-germinating (AG) seeds of Erodium oxyrhynchum. Plants in field plots with simulated increases in precipitation of 0, 30 and 50 % in spring and summer were monitored to determine seedling survival, phenology, plant size, seed production and biomass accumulation and allocation. Germination characteristics were determined in the laboratory for seeds produced by plants in all increased precipitation treatments. Increased precipitation in spring significantly improved survival …


Iceland's Migratory Birds In Changing Environmental Conditions: An Interactive Synthesis, Frances J. Duncan Apr 2019

Iceland's Migratory Birds In Changing Environmental Conditions: An Interactive Synthesis, Frances J. Duncan

Independent Study Project (ISP) Collection

Human-driven changes to environmental conditions alter the habitats, behaviors, and migration patterns of migratory species. Changes in temperature, vegetation, and precipitation are just some of the factors contributing to shifts in phenology, demography, and distribution of migratory birds. These changes are driven by anthropogenic climate change and amplified by human land-use change, and are especially intense at high latitudes. This project creatively communicates the effects of environmental changes on three species of migratory birds in Iceland—the northern wheatear, the Greenland white-fronted goose, and the black-tailed godwit—using principles of storytelling and game design. The resulting interactive product is a game that …


Food And Earth Systems: Priorities For Climate Change Adaptation And Mitigation For Agriculture And Food Systems, Ana Maria Loboguerrero, Bruce M. Campbell, Peter J.M. Cooper, James W. Hansen, Todd Rosenstock, Eva Wollenberg Mar 2019

Food And Earth Systems: Priorities For Climate Change Adaptation And Mitigation For Agriculture And Food Systems, Ana Maria Loboguerrero, Bruce M. Campbell, Peter J.M. Cooper, James W. Hansen, Todd Rosenstock, Eva Wollenberg

Rubenstein School of Environment and Natural Resources Faculty Publications

Human activities and their relation with land, through agriculture and forestry, are significantly impacting Earth system functioning. Specifically, agriculture has increasingly become a key sector for adaptation and mitigation initiatives that address climate change and help ensure food security for a growing global population. Climate change and agricultural outcomes influence our ability to reach targets for at least seven of the 17 Sustainable Development Goals. By 2015, 103 nations had committed themselves to reduce greenhouse gas emissions from agriculture, while 102 countries had prioritized agriculture in their adaptation agenda. Adaptation and mitigation actions within agriculture still receive insufficient support across …


Does Household Capital Mediate The Uptake Of Agricultural Land, Crop, And Livestock Adaptations? Evidence From The Indo-Gangetic Plains (India), Sameer H. Shah, Courtney Hammond Wagner, Udita Sanga, Hogeun Park, Lia Helena Monteiro De Lima Demange, Carolina Gueiros, Meredith T. Niles Jan 2019

Does Household Capital Mediate The Uptake Of Agricultural Land, Crop, And Livestock Adaptations? Evidence From The Indo-Gangetic Plains (India), Sameer H. Shah, Courtney Hammond Wagner, Udita Sanga, Hogeun Park, Lia Helena Monteiro De Lima Demange, Carolina Gueiros, Meredith T. Niles

College of Agriculture and Life Sciences Faculty Publications

Farmers in the Indo-Gangetic Plains produce much of the wheat and rice grown in India. However, food production and millions of farm-based livelihoods in this region will continue to be adversely affected by hydro-climatic change and variation, reduced land productivity, and declining groundwater levels. Thus, agricultural adaptations are essential for protecting and improving upon intersecting goals of food security, poverty alleviation, and wellbeing. Household “capital” (e.g., natural, human, financial, physical, and social) is commonly cited as an indicator of livelihood adaptability and innovation. We develop a series of mediated structural equation models to empirically evaluate the validity of capital as …


Creative Citizen Science Illuminates Complex Ecological Responses To Climate Change, Abraham J. Miller-Rushing, Amanda S. Gallinat, Richard B. Primack Jan 2019

Creative Citizen Science Illuminates Complex Ecological Responses To Climate Change, Abraham J. Miller-Rushing, Amanda S. Gallinat, Richard B. Primack

Biology Faculty Publications

Climate change is causing the timing of key behaviors (i.e., phenology) to shift differently across trophic levels and among some interacting organisms (e.g., plants and pollinators, predators and prey), suggesting that interactions among species are being disrupted (1, 2). Studying the phenology of interactions, however, is difficult, which has limited researchers’ ability to zero in on changes in specific interactions or on the consequences of mismatches. In PNAS, Hassall et al. (3) use a combination of citizen science techniques to investigate the effects of climate change on dozens of specific interactions. They focus on a Batesian mimicry complex involving stinging …


Deciduous Shrub Encroachment Effects On Tundra Soil Properties, Daniela Aguirre Jan 2019

Deciduous Shrub Encroachment Effects On Tundra Soil Properties, Daniela Aguirre

Open Access Theses & Dissertations

Deciduous shrub abundance is increasing in tundra ecosystems as an effect of rising temperatures which may change tundra physical properties and, in turn, microbial communities and biogeochemical processes. Two mechanisms through which shrub presence may affect tundra ecosystems were examined in this study; the physical presence of the shrubs and effects of increasing shrub litter inputs. In a sub-arctic alpine tundra ecosystem, dominated by the deciduous shrub Betula glandulosa, both shrub presence (shrub present and removed) and litter quantity (no litter/litter removed, ambient litter, and twice ambient litter) were manipulated; multiple ecosystem properties where measured within the treatment plots over …