Land Fragmentation in the Champlain Basin
Charlotte Lowe
Matt Gustafson
Walker Brown
Problem Statement
Land Fragmentation, in the Lake Champlain Basin, has a dramatic effect on the function, value, and quality of wetlands, riparian areas, and forested landscapes through disrupting the natural dynamics of these systems.
Goal/Purpose Statement
At the completion of this group’s assessment of land fragmentation and its effects on wetlands, riparian areas, and forest landscapes relative risk ranks will be assigned to each sub watershed. Using a GIS approach[PK1], a land fragmentation assessment [WBB2]will be conducted delineated by watersheds. With the power of ArcView mapping, a functional map will be available to compare the effects of fragmentation by watershed.
Justification
As humans take over a landscape, they tend to have a significant impact by clearing areas to make them available for human use. This creates gaps that make it difficult for wildlife to move fluidly across the landscape, as well as disrupting the natural dynamics of ecosystems. There are many detrimental ecological consequences associated with this fragmentation of the landscape, and we have only just begun to truly understand what these are and how to quantify their effects.
Most wildlife species need fairly large areas of habitat [PJ3]to sustain a viable population. Many even need long, uninterrupted corridors that allow them to migrate to different areas during certain seasons. By creating large gaps in the landscape or dangerous barriers such as highways, we have made it difficult for wildlife to flow across the landscape. This can generate isolated pockets of habitat where there is no exchange of genetic material, leading to inbreeding and unsustainable populations. Other constituents of the ecosystem need to be able to exchange genetic material as well, as in the pollination of flowers. Without this exchange, the ecosystem becomes stagnant and can degrade quickly, allowing for invasive species to invade the weakened area.
Fragmented habitat also becomes less resilient and resistant to disturbances. If major structures and components of the ecosystem sustain heavy damage during a disturbance event, the area may not be able to recuperate because the biological legacies are not close enough or in high enough concentrations to contribute to the recovery. This is another opportunity for fast-spreading invasive species that are well adapted to these damaged areas to colonize and take over.
By assessing habitat fragmentation in a region, we can observe where it is having the biggest[PK4] effect. In this way, we can begin a restoration effort on the areas most at risk and help to revitalize the native ecosystems of Vermont. [PK5]
Literature Review[PK6]
David Lindenmayer, Joern Fischer. (2006). Habitat Fragmentation and Landscape Change; An Ecological and Conservation Synthesis. Connecticut: Island Press.
A comprehensive look at fragmentation in a variety of habitats. Description of effects on habitats and receptors from a complex systems approach. Potentially useful to justify and describe the problems associated with landscape fragmentation. Also, useful for determining and assigning a risk ranking to landscape fragmentation.
Ally, D., Ritland, K., (2006). A Case Study: Looking at the Effects of Fragmentation on Genetic Structure in Different Life History Stages of Old-Growth Mountain Hemlock (Tsuga mertensiana[PJ7][WBB8])
This paper outlines a study performed on eastern hemlock in old growth stands compared to stands fragmented and analysis the effects of fragmentation on genetic and structural diversity. The study found that fragmentation, on a large scale, can increase the structural diversity of hemlock stands. However, on a micro scale loses to genetic diversity and structure occurred more apparently.
Anderson, Mark G. et al. "The Northern Appalachian/Acadian Ecoregion: Priority Locations for Conservation Action." Two Countries, One Forest. Special Report No. 1 (2008)
This article will help us to understand how to prioritize which areas are the most important and which need the most attention. It focuses on the landscapes of the Northern Appalachian and Acadian region, which is a similar climate to Vermont.
Collingham, Yvonne C., and Brian Huntley. "Impacts Of Habitat Fragmentation And Patch Size Upon Migration Rates." Ecological Society of America. 10.1 (2000): 131-144.
This article will help us understand what the effects are of landscape fragmentation on the migration of wildlife and other components of the ecosystem. It mentions animal’s movement across the landscape as well as plants whose populations gradually move with a changing climate.
Glennon, M., Kretser, H. (2005). Impacts to Wildlife from Low Density, Exurban Development: Information and Considerations for the Adirondack Park.
The scope of this paper was the effects of urban [PJ9]development as the cause of fragmentation on wildlife. The study outlines how urban development and the infrastructure such as roads that result dramatically affect the natural dispersal of many wildlife species.
Lake Champlain Basin Program. (2011, March 2). Opportunities For Action; An evolving plan for the future of the Lake Champlain Basin. Retrieved from
Connection to stakeholders concerns, goals, objectives, tasks, and other information.
Leoniak, G., Sharf, T., et. al. (2009). Critical Paths; Enhancing Road Permeability for Wildlife in Vermont.
This paper is specific to Vermont (geographical relevance), discussing the impacts of transportation systems on wildlife populations. Contains connections between source (transportation), stressor (landscape fragmentation), and habitats/endpoints (associated habitats/wildlife populations). Specifically discusses impacts of fish.[WBB10]
Proposed Effort[PK11]
In order to effectively and subjectively[WBB12] assess the effects of fragmentation in the Lake Champlain Basin the GIS platform ArcView will be utilized to perform the assessment. Using data layers publically available, including road layouts and land use maps, the watersheds can be analyzed to subjectively[WBB13] assess the effect fragmentation has on the region. The current design of this analysis would be to compare the amount of land currently developed to the land undeveloped (currently forested, wetlands, etc.) as well as an analysis of how roads also fragment the landscape[PJ14]. Using this analysis, ranks (2, 4, and 6 ranking from low to high) would be designated to each watershed by comparing the relative fragmentation effects calculated. A map will then be produced showing the relative risk fragmentation has on each watershed using GIS. Then, using previous literature reviewed, inform decisions on management in respect to land fragmentation and the risk and potential consequences to each watershed. This will be outlined in a report discussing the findings of this assessment including the risk rankings, methods for determining risk scores, discussion of implications of risk assessment, and management suggestions informed by research and the relative risk model. As the GIS analysis discussed above is still only a concept (we are seeking mentoring from a professor at UVM in GIS technologies) there are a number of issues unforeseen. Some issues anticipated are if the risks to each watershed calculated using GIS are similar the resulting ranking of those risks will be problematic. Also, because land fragmentation has dramatic effects on terrestrial ecosystems as compared to aquatic ecosystems it is anticipated that it will be difficult to assess the risk to each watershed. As such our group proposes that roads/transportation be isolated either within one of the current sources or broken out into a separate source[PJ15]. Another proposal is to add a habitat catch-all category that can include early successional habitat, non-high value forestlands, and generally all terrestrial areas that don’t already fall under our current habitat categories.[WBB16]
Effort Assignment[PK17]
Responsibilities involved in the formation of this ERA will be shared among the three project members. All three members will be involved in active research concerning landscape fragmentation to collect as much relevant information as possible. Charlotte Low will provide an introduction into the background of landscape fragmentation, justifying it as a stressor of concern. Walker Brown will compile a list and short discussion on stakeholders involved with the particular stressor. Matthew Gustafson, will use his previous experience with GIS mapping to create comprehensive maps showing the concentration of this stressor throughout the Lake Champlain Basin. These maps will be used to evaluate risk associated with landscape fragmentation. Walker Brown is responsible for describing the risk ranking system and the scoring methods associated with it. Charlotte Low is assigned with the task to outline and evaluate uncertainty and incorporate it into the ERA. The group as a whole will synthesize recommendations to mitigate landscape fragmentation, and formulate a conclusion to this section of the ERA. Throughout the duration of this process, all three group members will meet together weekly. A Google Document will be created to facilitate a level of communication at all times and encourage the exchange of feedback[PJ18][WBB19].
[PK1]Great!
[WBB2]It’s not clear to me how you will actually do this. What metric(s) will you focus on to define “fragmentation”?
[PJ3]I’m not sure if you can say “most”. Lots of species use relatively little area, i.e. amphibians compared to bears. Keep scale in mind.
[PK4]Largest? Or of greatest impact?
[PK5]Great, good to know the “so what” and how/why this will be used.
[PK6]Great job on the annotated bib. Your l iterature is relevant and you have a good understanding of its applicability and need for your research.
[PJ7]It’s good that you’re thinking more broadly than wildlife.
[WBB8]I agree in general, re: widening the viewpoint. However, specifically, I’m not sure that hemlock stands are particularly important the LC basin. Perhaps on the NY side?
[PJ9]Exurban/suburban development, not urban. Very different things.
[WBB10]Good start on literature. Some nice papers to consider here and good summaries of each.
[PK11]Excellent! This is detailed and feasible. Your step by step methodology will clearly help you down the line.
[WBB12]Do you really mean “subjectively”? Don’t you really want to do this “objectively”?
[WBB13]same
[PJ14]What about an analysis that compares % of each watershed that is made up of undeveloped patches over a certain size without large roads? This type of quantification would probably tell you more than developed vs undeveloped. Will you group ag lands with other development?
[PJ15]Seems like a good idea
[WBB16]This is good start; I like the detailed thinking that has gone in to this so far. Don’t underestimate the complexity of defining and then quantifying “fragmented” land, however. This will require some further careful thought. People like Dave Capen and Allan Strong may be able to help.
[PK17]Well outlined on your delegation of responsibilities.
[PJ18]You sound organized
[WBB19]I agree. Looking good. As is I assign a grade of A at 93%. If you address the minor points above and resubmit I will raise this to 96%.