New Jersey
Forest Stewardship Program
Spatial Analysis Project
2007
Map Products
And
Data Layers Descriptions
01/07
NJ Forest Stewardship Program (FSP)
Spatial Analysis Project (SAP)
Methodology
Project Summary:
The National Forest Stewardship Spatial Analysis Project (SAP) determines stewardship
potential on private non-developed lands. A raster based GIS approach was applied to the
various data layers at a one half-acre cell size. The individual data sets were then rated by
the Stewardship Committee on relative program importance. A statistical weighting
system was than applied to develop the threat factors and stewardship potential for
individual units. A final data output was produced by separating the data at three natural
breaks for high, medium, and low stewardship potential.
Data Layers Resource Factors:
Private Forest Lands
Forest Patch Size
Riparian Corridors
Public Water Supply
Priority Watersheds
Threatened and Endangered Species
Wetlands
Proximity to Publicly Owned Lands
Protected and Public Lands
Slope
Resource Threats:
Development Risk
Forest Health Risk
Land Mask:
Those areas not eligible for inclusion in the Forest Stewardship Program (FSP) were
aggregated into a single mask layer and excluded from the analysis. These include all
developed land, streams, water bodies, and permanently protected land parcels.
Layer Creation:
The 12 data layers selected for this analysis were converted to a raster grid format using a
common point of origin at a standard one half acre cell size. Each individual layer was
rated as to its importance relative to the Stewardship Program by committee members.
These values were than weighted and the cells of each layer coded appropriately. The
analysis overlays the 12 layers and then sums the values of each cell of every column
producing an output layer. This Stewardship Potential output layer can have a possible
value ranging from zero to one. A cell column with no hits in any layer would have a
value of zero, while a cell column with hits in all layers would produce a value of one.
Forest Stewardship Data Layers
The output values of the Stewardship Potential layer generated in the analysis ranged
from a low of .068 to a high of .856. Meaning that no single column of cells was a hit or
miss in all 12 layers. The resulting data range was than separated into three natural breaks
by the Jenks method. This classification translated to low, medium, and high ranges
facilitates the evaluation process and graphical display of the data set.
Possible Data Values
Wildfire Hazard: - (data rank = .079)
The Wildfire Hazard layer was created using both the
NJDEP land use / land cover vegetative data and USGS 10meter digital elevation models (DEM). The lulc data at a
minimum unit size of 2.5 acres, classified with a modified
Anderson et al. classification was aggregated into six
hazard categories. Based on fire fuel models produced by
the vegetative associations they range from low, moderate,
high, very high, to extreme. These classified units were
than adjusted for the influence of slope and aspect with the
DEM models. These hazard classes form the basis for
prioritizing hazard mitigation projects, the development of
Community Wildfire Protection Plans, and the
administration of regulated defensible space issues by the
NJ Pinelands Commission.
For this analysis the categories of high and extreme risk
were included in the Wildfire Hazard layer. This targets
properties essential for reducing the potential of wildfire
risk to private forested lands through stewardship and forest
management activities.
Forest Patch: - (data rank = .098)
The Forest Patch layer was generated using the NJDEP
land use / land cover vegetative data. All forested and early
successional polygons were dissolved to produce a single
forest cover layer. Forested patches of 25 acres and greater
were selected for inclusion in the analysis layer. This value
was selected so as not to exclude the many small property
owners common in our fragmented forests. The average
FSP acreage in NJ is approximately 106 acres, selecting 25
acres should help prioritize small properties for inclusion
into the FSP reducing the amount of forest patch
fragmentation.
Public Land Proximity: - (data rank = .088)
This data layer is the product of the union of two
separate data sources. The first is a one-half mile
(2,640 feet) buffer of all permanently preserved open
space. Preserved open space is considered to be state lands
(Div. Parks and Forestry, Natural Lands Trust, Fish &
Wildlife Management Areas), federal property (National
Recreation Areas and military installations), and county or
municipal lands (parks). The second source incorporates
data from the Garden State Greenways Project. A joint
effort between the NJ Dept. of Environmental Protection’s
Green Acres Program, the NJ Conservation Foundation,
and Rutgers Center for Remote Sensing and Spatial
Analysis (CRSSA). This project identifies hub areas of
undeveloped land such as parks and forests and linear
undeveloped connectors between these hubs. These
connectors or undeveloped corridors have been
incorporated to supplement buffered preserved land and
encourage forest stewardship between preserved open
space parcels.
Threatened and Endangered Species: - (data rank = .068)
This Data layer was produced utilizing the NJ Division of
Fish and Wildlife’s, Endangered and Nongame Species
Program data, NJ Natural Heritage Database and, the
Natural Lands Trust (NLT) data layers for T&E species.
Areas where polygon attributes indicated that one or more
Code 5 species (Federally Endangered) was present or
where NLT exceptional habitat existed was selected for
inclusion. This data layer prioritizes properties that have
T&E species present or good potential habitat for inclusion
in the FSP. By prioritizing these properties, T&E habitat
and the local populations can be maintained or enhanced
through forest stewardship activities.
Developmental Land Use Change: - (data rank = .075)
This data layer identifies areas of development pressure.
Land use / land cover data was used to track the change in
acreage from private forest to developed land for each
HUC 11 unit over the previous ten year period. Areas
experiencing the highest levels of change per unit (up to 9.9
percent) were selected as priority areas for stewardship
potential. Many of the remaining unselected HUC units are
in areas which have existing protocols and/or regulations in
place to preserve land or restrict development. These
include the NJ Pinelands Preservation Act, the NJ
Highlands Act, and Coastal Area Facility Review Act
(CAFRA) zones, There fore, selecting these HUC 11 units
as priority for the Stewardship Program will entice
woodland owners to enroll in the FSP and maintain a nondeveloped land use such as forest.
Forest Health: - (data rank = .088)
This layer prioritizes areas that have a documented history
of being at risk to forest pests and disease or are a declining
forest type of ecological significance. It was generated
utilizing NJFS Stress Risk Maps, Forest Health Monitoring
data (FHM), Damage Causing Agents surveys (DCAs) and
NJFS forest resource maps. In the case of oak defoliation,
up to twenty years of digital DCA data was utilized to
identify historical gypsy moth hot spots. While many forest
types have the potential for DCA susceptibility, Eastern
hemlock, southern yellow pine and Atlantic white-cedar
were additionally selected for prioritization. These forest
types have experienced decline and mortality due to
hemlock woolly adelgid (HWA), southern pine beetle
(SPB) and lack of proper forest management, respectively.
Prioritization and incorporation of these forest types will
encourage suppression, monitoring and restoration efforts.
In the future, ash (Fraxinus spp.) will be incorporated in
this group for the monitoring of Emerald ash borer (Agrilus
planipennis) to facilitate early detection / rapid response.
Fresh Water Wetlands: - (data rank = .076)
This data layer was generated from the NJDEP land use –
land cover data set with a minimum mapping unit of 2.5
acres. The modified Cowardin classifications relating to the
appropriate forested and non forested freshwater wetlands
designations were reselected and dissolved to produce a
single inclusive wetlands coverage.
Riparian Buffers: - (data rank = .094)
The riparian buffer layer was created by the union of the
NJDEP state hydro coverage of water bodies and streams
generated from USGS 1:24000 digital line graph files. The
stream lines and freshwater water bodies were buffered by
300 feet on each side. Islands with less than five acres of
area or less were removed.
Public Water Supply: - (data rank = .087)
This data layer was generated by utilizing a series of
NJDEP public water supply data sources. Public supply
well heads, reservoirs, lakes, and all surface water bodies
with intake points were merged into a single data set and
buffered by 5,280 feet. In order to protect and maintain
water quality these areas adjacent to public water supplies
will be encouraged to enter the stewardship program.
Slope: - (data rank = .074)
This data layer prioritizes properties with slopes values of
less than 40 degrees for inclusion into the FSP. Individual
lattices produced from USGS 10 meter digital elevation
models (DEMs) for the twenty state watershed
management areas were merged and slope values
generated. Units with slopes values of less than 40 percent
will receive priority for program participation there by
mitigating potential erosion through stewardship activities.
State Priority Watersheds: - (data rank = .099)
Priority watersheds were selected by HUC 11 series units
using data from the NJ Bureau of Freshwater and
Biological Monitoring Program. The Category 1 (C1)
Streams were selected due to their high ecological resource
and recreational values. Values are related but not limited
to drinking water, fisheries and aesthetics. Category 1
waters are defined by the regulations on Surface Water
Quality Standards N.J.A.C. 7:9B. In addition to C1
streams, the NJDEP Wild and Scenic Rivers (WSR)
coverage was added This data set targets stewardship
planning activities in order to maintain the high resource
value of the water management unit, encouraging the
continued protection and improved water quality of these
priority watersheds.
Private Forest Lands: - (data rank = .074)
The Private Forest Lands layer was generated using the
NJDEP land use / land cover vegetative data. All
appropriately classified forested units from this modified
Anderson system were selected. An identity was conducted
to remove all state, federal, county and municipal lands.
Analysis Mask:
The Analysis Mask contains those areas unavailable for
inclusion into the forest stewardship program and therefore
not included in the analysis. The NJDEP land use land
cover data was used to identify all areas with inappropriate
classifications. These included but were not limited to
residential, industrial, commercial, urban areas, saline
marsh, streams, natural and artificial lakes. This coverage
was unioned with all federal, state, county, municipal and
protected lands. The layer was than dissolved, converted to
the standard half acre grid format and coded with a cell
value of five for later reselection and removal from the
final data set.
GIS Analysis:
The analysis process is relatively simple, the twelve individual data layers were each converted
to a standard one half acre grid format. The cells of each layer were than coded with the
appropriate data value corresponding its weighted resource value. This stack of twelve
overlapping data sets is then analyzed to produce a single output grid containing the sum of
values from each overlapping cell. The true data range is from zero to one, any cell which was
included in the mask layer produces a value equal to or grater than five. These mask cells were
then removed from the output layer. This output layer was then divided into three natural breaks
by the Jenks method. These three classifications of high, medium, and low stewardship potential
were individually selected out and converted to separate polygon layers. The separation of layers
facilitates area calculations, distribution to regional offices, graphical display, and additional
analysis efforts.
Stewardship Plan Ownership Boundaries:
New Jersey Forest Stewardship Plan boundary maps have been recorded in various forms with
differing spatial accuracy, scales, and precision since the beginning of the program. All available
stewardship property records will be incorporated in this project. Digitizing efforts are currently
under way with an expected completion date of June 2007. Upon completion the NJ data base
should contain in excess of over 900 plans incorporating over 100,000 acres.
Forest Stewardship Potential:
The NJ spatial analysis project results have provided interesting and valuable insights into future
potential program benefits to our states private lands sector. As development and population
pressures increase the ability to target prime resource rich candidates for program inclusion
become paramount. New Jersey's available stewardship acreage displays considerable potential
for future entrance into the program with over 66% of all available acreage being of moderate or
high resource value.
This new approach aimed at prioritizing and targeting properties by resource potential produces
additional program benefits. Program managers will now have the necessary tools to assess the
true impact made at the landscape level. New initiatives can be implemented and directed to
produce maximum returns regarding time and dollars invested. Program accountability and
importance can now be evaluated across state lines at a national scale. This new standard will
help to ensure the future of the Forest Stewardship Program and the resource benefits it produces
for us all