Note: Background information to supplement the lecture material is available at https://www.dcr.virginia.gov/natural-heritage/vaco….
For this exercise, you will be using the Virginia Department of Conservation and Recreation (DCR) online mapping tool. To start, go to https://vanhde.org/content/map.
You will start with the layer Conservation Planning à Ecological Cores. You can also turn on the layers for VDOT roads as well as streams.
Ecological cores include “identified large (>100 acres), unfragmented cores” via the GIS analysis of the Virginia Natural Landscape Assessment (VaNLA), and are given scores depending on ecosystem services provided – in general, larger more diverse areas are given higher scores.
How many ecological cores do you see inside the beltway?
What are some of the largest ecological cores you see in Fairfax, Loudoun, and Prince William Counties? (Name any nearby landmarks/park names) Also note what colors (scores) they have.
Use the “Measure” tool next to the “info” tool on the bar to measure area. What is the largest size of a patch inside the beltway that you see? Change the units to acres or hectares. You can approximate the area measurement.
Does this fit the general requirement noted by Lepczyk et al. (2017) for 10 to 35 hectares (~25 to 80 acres)? Do you think that means it is sufficiently helping to sustain populations of wild species? – why or why not?
Look for a series of patches connected by minimal space. You can add the Conservation Planning à Natural Land Network layer on to help you with this, as this layer will connect all ecological cores ranked from high to outstanding together.
What are some connected areas you have found? What kind of shape do they make altogether? (linear, square, circular, dendritic, etc)
Are these areas interrupted by road crossings?
What condition (seen as color) are these patches in? (Turn off Natural Land Network if you turned it on)
Zoom in and try to see if these are connected by a connected system of land management (e.g., Wildlife Refuge, county park/trail system) or if they tend to exist in a certain area in their watersheds (e.g., riparian areas, residential areas).
Next, keeping the Ecological Cores layer turned on, turn on the Managed Conservation Lands layer (under its own heading). You are going to compare areas under managed conservation lands to ecological cores.
Compare areas connected by managed conservation lands and areas connected/identified as ecological cores. Which dataset seems to be more expansive in overall area?
Using the definitions of ecological core vs. managed conservation land, explain why you see this pattern in spatial extent for managed conservation lands versus ecological cores.
Fairfax County has lands designated a part of its conserved land network that include resource protection areas (RPAs) along all perennial streams within the county and certain 100-year floodplains, which are zoned for the Chesapeake Bay Preservation Act and Ordinance.
Additionally, these conservation lands include those that are a part of the County’s Environmental Quality Corridor system (EQC) that was created to “identify, protect, and enhance an integrated network of ecologically valuable land and surface waters for the present and future residents of Fairfax County.” This land, mostly stream valleys, is designated based on achieving various ecosystem services, including one or more of the following:
You are given everything you need to allocate 500 acres of land to conservation of habitat for biodiversity – in particular, limiting edge habitats that hurt various species of birds, plants, insects, etc. Pretending property rights don’t matter, how would you make the most of this land — would you expand on current corridors or try to create patches in more urbanized areas inside the beltway? There is no right answer, but explain your reasoning.
-Desirable or scarce habitat for rare/threatened/endangered species;
-Providing breeding habitat for aquatic/wetland organisms;
-Potential corridor land for movement of wildlife and/or biodiversity conservation; and
-Riparian area providing shade, stabilization of stream banks via vegetation, flood storage, dissipation of stream energy, and other floodplain ecosystem services.
Figure 1. Example section of a stream valley included in the Fairfax County EQC.
You can read more at www.fairfaxcounty.gov/environment-energy-coordination/sites/environment-energy-coordination/files/assets/documents/eqac/2021%20eqac%20are_a-1a.pdf.
Identify and name the general locations for a few managed conservation lands that provide connectivity between isolated ecological cores. Are they mainly in stream valleys? What is their general shape/size?
Evaluate the general aim of the EQC system to connect ecological cores. Do you see any areas where conservation lands need to be expanded for the network of ecological cores? (Name a few.)
Identify some of the widths (in meters, m) of the managed conservation lands around streams that are a part of the EQC or RPA network, but not part of the Ecological cores.
Large wildlife has been estimated to need corridors with ~ 2 km widths; birds have been estimated to need much less, with a parabolic relationship that leads to a positive relationship up to widths of ~50-80 m and a negative relationship with widths over 80 m (Askins et al. 2012). Do you think these conservation lands can benefit large animals? What about birds? What sorts of organisms do you think would be most benefited from these corridors?
Ecological cores require a large enough in-tact interior area to protect species from impacts of human activity, edge-thriving predators like foxes and raccoons, invasive species, and inbreeding. Looking at satellite imagery / landcover around the conservation network, what recommendations would you make to the EQC zoning to improve the success of the conservation corridors? Think about: Size
Insulation from urban habitat (“buffer zone”)
Any other ideas you obtained from the lecture, reading Lepczyk et al. (2017) or https://www.dcr.virginia.gov/natural-heritage/vaco….
Figure 2. Parabolic relationship between bird species richness and width of corridors (example figure made from Askins et al. 2012).
Because property rights do matter, you cannot zone 500 acres of private property for your conservation aims. What are some small-scale habitat efforts you can push for or market for habitat and ecosystem conservation? There is no right answer, but explain your reasoning.