ALASKAN PONDS AND THEIR MIGRATORY BIRD AND INSECT COMMUNITIES IN A CHANGING ARCTIC: DEVELOPMENT OF A LONG-TERM INVENTORY AND MONITORING PLAN FOR IZEMBEK NATIONAL WILDLIFE REFUGE
Open Access
- Author:
- Ikis, Didem
- Graduate Program:
- Biology
- Degree:
- Doctor of Philosophy
- Document Type:
- Dissertation
- Date of Defense:
- December 15, 2017
- Committee Members:
- Tracy Lee Langkilde, Dissertation Advisor/Co-Advisor
Victoria Anne Braithwaite-Read, Committee Chair/Co-Chair
Tomas A Carlo-Joglar, Committee Member
David Andrew Miller, Committee Member
Eric Post, Outside Member - Keywords:
- BIODIVERSITY
CLIMATE CHANGE
GLOBAL CHANGE
COMMUNITY ECOLOGY
PHENOLOGY
SPECIES-AREA RELATIONSHIP
CONSERVATION
ALASKA
ARCTIC
PONDS
INVENTORY & MONITORING
ENVIRONMENTAL STRESSORS
NATURAL RESOURCE MANAGEMENT - Abstract:
- Natural and human-induced environmental stressors, particularly climate change, have a wide range of effects on Alaskan natural system. All ecosystem types, from terrestrial to aquatic, have been influenced by the drastic temperature increases experienced in high latitudes. It is therefore crucial to determine the potential effects of environmental stressors in order to anticipate Alaska’s future, and to include those findings in the decision-making process. To achieve these goals, I designed this project in two portions: an inventory and monitoring (I&M) plan, and a focal study on the phenology of Alaskan wetlands and associated avian and invertebrate communities. The first portion of this project centered on the development of two decision-making frameworks designed to help organizations determine the priorities for their inventory (extensive sampling) and monitoring (intensive sampling) programs. As the U.S. Fish and Wildlife Service (USFWS) has increased its efforts to develop guidelines for inventory and monitoring programs at the refuge, regional, and national levels, I worked with Izembek National Wildlife Refuge (NWR) to develop a system to guide their efforts. For the inventory program, I designed a framework to help the refuge prioritize which species to include in the inventory. This system includes an evaluation of the ecosystem types, including the biotic/abiotic components, and the effects of environmental stressors in order to detect changes in the refuge’s ecosystems. A second framework was developed for the monitoring portion, which complements and builds upon the inventory prioritization. The goal of this decision-making framework is to populate a list of species of concern with their relative prioritization rankings, as determined by each species’ vulnerability to environmental stressors, in order to make informed management decisions on which environmental resources of the refuge necessitate monitoring efforts. In the second portion, I demonstrated an example of the type of studies that could be performed to inform the inventory and monitoring plan. The case study I developed targets the relationship between the Alaskan wetland system, migratory bird communities and the invertebrate communities on which these breeding birds rely on. Specifically, I investigated the interaction between pond area and bird community structure, as well as the phenology of migratory bird arrival and insect emergence. The project focusing on the relationship between pond area and bird community structure assessed how migratory birds occupy different size ponds, and which environmental variables affect bird communities. By using a space-for-time approach, this study was structured to investigate the possible outcomes of climate change on Alaskan wetland systems. The findings of this study show that pond area has a significant effect on the diversity and composition of bird communities, with larger ponds supporting more species. In addition, both functional groups and individual species show preferences for particular pond size categories. Dabbling ducks primarily utilize larger ponds, and sandpipers show a preference for smaller ponds. These results help us to understand the pond size-bird occupancy relations in Arctic wetlands in order to anticipate the possible effects of climate change on bird species dependent upon resources of high-latitude communities. The project focusing on insect emergence and bird arrivals was developed to investigate the temporal components of insect emergence and bird occupancy in different size ponds. Considering migratory birds’ reliance on ponds as their food resource during the breeding season, it is crucial to understand how any changes in pond size and number may affect migratory birds. The models of insect emergence reveal that insect productivity has a strong relationship with pond area, day of year and minimum water temperatures. The occupancy models of 2012 indicate that smaller ponds were saturated by bird species rapidly early in the season, but larger ponds had steady and lower rates of bird arrivals. In 2013, however, all ponds were occupied by birds early in the season with almost the same accumulation rate. Considering these patterns in the timing of bird arrivals and insect emergence in Alaskan wetlands, any significant changes in pond size and number may affect availability of food resources for migratory birds, and impact their breeding success. Whether Alaskan wetlands shift towards larger or smaller ponds, these changes may force functional groups and individual species to share resources and increase competition.