Biodiversity Commons^™

Spatial And Temporal Variation In The Aquatic Invertebrate Community Structure Of Rock Pools Along The Penobscot River, Maine, Chase R. Gagne

Electronic Theses and Dissertations

Pools of water that form in the fissures and depressions of rock outcrops, known as rock pools, are fairly common aquatic habitats that can easily be found along the rocky banks of many of Maine’s major rivers. In general, rock pools and the aquatic invertebrates inhabiting them have received little research attention and, though ubiquitous, have never been studied in Maine. My research addressed this knowledge gap by surveying 40 rock pools at four sites along the Penobscot River in Maine. The rock pools themselves had highly variable environmental characteristics and differed across sites and over time, especially in hydroperiod. …

Landscape Pattern And Wild Bee Communities In Maine, Brianne Du Clos

Electronic Theses and Dissertations

Commercial production of lowbush blueberry (Vaccinium angustifolium Aiton) in Maine relies primarily on managed honeybee hives; however, naturally occurring wild bees are more efficient pollinators of the crop. Wild bees have short foraging distances and must nest near crop fields to provide pollination services. After crop bloom, the surrounding landscape must provide sufficient forage to maintain wild bee populations for the remainder of the growing season. Lowbush blueberries in Maine are produced in a mixed-use landscape with two distinct landscape contexts. Here, we document bee communities and habitat resources (nesting and floral) in power line rights-of-way and eight land …

Niche Evolution Along A Gradient Of Ecological Specialization, Meaghan Conway

Electronic Theses and Dissertations

The concept of the ecological niche is fundamental to understanding constraints on species distributions in space and time, and in explaining the origin and maintenance of biodiversity. A niche can be broadly defined to include all of the biotic and abiotic conditions that a species requires to persist. Niche breadth, or the degree of specialization, may influence how labile a species niche is, which can have broad implications for species ability to adapt to environmental change, and for explaining patterns of diversification. I investigated mechanism that facilitate or constrain niche evolution at multiple scales. First, I developed an index of …

Repeat Disturbances Have Cumulative Impacts On Stream Communities, Jessica M. Haghkerdar, Jack R. Mclachlan, Alexis Ireland, Hamish S. Greig

Biology and Ecology Faculty Scholarship

1. Climate change has altered disturbance regimes in many ecosystems, and predictions show that these trends are likely to continue. The frequency of disturbance events plays a particularly important role in communities by selecting for disturbance -tolerant taxa.

2. However, ecologists have yet to disentangle the influence of disturbance frequency per se and time since last disturbance, because more frequently disturbed systems have also usually been disturbed more recently. Our understanding of the effects of repeated disturbances is therefore confounded by differences in successional processes.

3. We used in -situ stream mesocosms to isolate and examine the effect of disturbance …