Forest and Green Infrastructure Loss in Maryland 1997-2000,
and Implications for the Future


A street sign with the name Wildland Drive outside a development Abstract

We used Geographic Information Systems (GIS) techniques and field assessment to examine land conversion between 1997 and 2000. Our objectives were to determine patterns of forest loss, impacts to natural landscape connectivity (specifically, to Marylandís green infrastructure hub-corridor network), and to predict future trends. We found that Garrett county lost the most forest (over 7000 ac) of any county in Maryland between 1997 and 2000, and by far the most green infrastructure forest. By region, Western Maryland lost more green infrastructure (over 8600 ac) than the rest of the state combined. Most of its forest loss was in formerly large, contiguous blocks; whereas much (71%) of the forest lost elsewhere in the state was in small or isolated woodlots, and outside the green infrastructure. This reflects the fragmented state of most of Maryland's forests. Western Maryland (especially Garrett County), on the other hand, contains more contiguous, more ecologically and economically valuable forest, but is now undergoing the same sort of exurban development and habitat fragmentation common in the central and southern counties. The Eastern Shore, where many recent (post-2000) land protection efforts have focused, suffered by far the fewest losses of forest and green infrastructure during the study period. Most of the forest lost between 1997 and 2000 was converted to low-density residences. In most cases, >50% of tree cover was retained on site after development, but the forest was fragmented. In addition to absolute forest loss, green infrastructure functional loss was significant. 7 hubs and 32 corridor segments, totaling over 13,000 ac, lost over 10% of their area. The hub-corridor network was interrupted in 28 areas. Fortunately, for 24 of the 28 broken routes, alternate pathways compensated for these obstacles, demonstrating the value of redundancy in conservation networks. However, if current trends continue, a large fraction of Maryland's green infrastructure may be seriously degraded by 2020. Finally, a development risk model performed better than random chance at predicting forest loss and, by using suitable thresholds, can help focus protection efforts. An improved development risk model is described at http://www.dnr.state.md.us/greenways/gi/risk/risk.html.

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Main Body
 
Forest and Green Infrastructure Loss in Maryland 1997-2000, and Implications for the Future
 
 
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1.92 MB
     
 
 
 
Appendix A
 
Green infrastructure forest loss 1997-2000
FIELD VERIFICATION SHEET

 
 
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0.03 MB
     
 
 
 
Appendix B
 
Locations of potentially significant impacts to the green infrastructure hub-corridor network, mapped by county
 
 
Allegany

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0.58 MB
Anne
Arundel

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0.76 MB
 
Baltimore

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0.83 MB
 
Calvert

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0.66 MB
 
 
Caroline

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0.63 MB
 
Carroll

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0.78 MB
 
Cecil

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0.73 MB
 
Charles

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0.85 MB
 
 
Dorchester

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0.73 MB
 
Frederick

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0.80 MB
 
Garrett

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0.65 MB
 
Harford

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0.82 MB
 
 
Howard

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0.79 MB
 
Kent

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0.67 MB
 
Montgomery

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0.70 MB
Prince
George's

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0.80 MB
 
Queen
Anne's

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0.65 MB
 
Somerset

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0.64 MB
 
St. Mary's

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0.70 MB
 
Talbot

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0.66 MB
 
 
Washington

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0.54 MB
 
Wicomico

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0.71 MB
 
Worcester

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0.73 MB
 
 
 


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