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Full-Text Articles in Ecology and Evolutionary Biology

Don't Delay: The Effects Of Tide Gates And Road-Stream Crossing Culverts On River Herring (Alosa Spp.) Spawning Migrations, Derrick J. Alcott Dec 2020

Don't Delay: The Effects Of Tide Gates And Road-Stream Crossing Culverts On River Herring (Alosa Spp.) Spawning Migrations, Derrick J. Alcott

Doctoral Dissertations

River herring (Alosa spp.) are anadromous fish that spawn in freshwater rivers and lakes in North America from Florida to Nova Scotia, CA. They have been listed as a species of conservation concern due to dramatic stock declines observed in the 1970’s. Stocks have failed to show significant signs of recovery despite over a decade of harvest restrictions throughout their range. Bycatch in commercial fisheries and reduced access to spawning habitat due to anthropogenic barriers to migration, such as dams and tide gates, have been identified as major causes of the decline in herring populations. Physical barriers to …


Improving Understanding Of Forest Communities And Biodiversity With Multi-Dimensional Landscape Gradients, Ben J. Padilla Dec 2020

Improving Understanding Of Forest Communities And Biodiversity With Multi-Dimensional Landscape Gradients, Ben J. Padilla

Doctoral Dissertations

This dissertation was motivated by a desire to understand the effects of habitat degradation and urbanization on a single species in a single study system in western Massachusetts, the red-backed salamander (Plethodon cinereus), but along the way unexpected conceptual and methodological hurdles caused the work to grow into a multi-species, multi-region, and multi-scale endeavor. As I designed my dissertation research and began considering approaches to quantifying heterogeneity and human influence in my study landscape, I recognized inconsistencies in methods used to define and quantify landscape metrics, particularly in urban systems. To investigate further, I conducted a critical review …


Root Phosphomonoesterase As A Vital Component Of Increasing Phosphorus Availability In Tropical Forests, Kristine Grace Manno Cabugao Dec 2020

Root Phosphomonoesterase As A Vital Component Of Increasing Phosphorus Availability In Tropical Forests, Kristine Grace Manno Cabugao

Doctoral Dissertations

Tropical forests, relative to other terrestrial ecosystems, exchange the largest amount of carbon with the atmosphere and also constitute a significant carbon sink. However, nutrient limitation, particularly of phosphorus (P), could limit growth of tropical forests and their function with the global carbon cycle. Thus, understanding root mechanisms to acquire P is necessary to representing the P cycle and corresponding interactions with plant growth. A large portion of total soil P in tropical forests occurs in organic forms, only accessible through root and microbial production of phosphatase enzymes. These phosphatase enzymes mineralize organic P into orthophosphate, the form of P …


Investigating The Effects Of Winter Drawdowns On The Ecological Character Of Littoral Zones In Massachusetts Lakes, Jason R. Carmignani Mar 2020

Investigating The Effects Of Winter Drawdowns On The Ecological Character Of Littoral Zones In Massachusetts Lakes, Jason R. Carmignani

Doctoral Dissertations

Anthropogenic alteration of water levels in lakes is a major stressor to the ecological integrity of littoral zones, which provide critical heterogenous resources that support diverse biological communities. Annual winter drawdowns have been practiced in Massachusetts (MA) for several decades; however, few studies have estimated impacts to littoral zone habitat and biological communities, particularly at relatively mild magnitudes (i.e., m) and in lakes that co-occur with other anthropogenic pressures (e.g., lakeshore development) as seen in MA lakes. My dissertation reviewed the winter drawdown literature and collected empirical data in MA lakes to characterize winter drawdown hydrological regimes and estimate responses …