The landscape of the ecoregion east of the Bay – the Delmarva Peninsula - is dominated by agriculture and characterized by low, flat sandy plains cut by wide, slow-flowing rivers bordered by extensive swamp forests and tidal marshes. To the west of the Bay, a broad plain with generally low slopes and gentle drainage divides is dissected by a series of major rivers – the Patuxent, the Potomac, the Rappahannock, the York and the James – that form a series of large, parallel peninsulas running into the Bay. The western shore in Maryland (especially the northern portion) is dominated by urban/suburban development around and between Washington, D.C., Baltimore and Annapolis. The western shore in Virginia is a lightly-developed, heavily forested area impacted by urban/suburban development near Richmond and Newport News-Hampton.

The CBY ecoregion also includes 140 miles of Atlantic coastline along the Delmarva Peninsula characterized by a complex and dynamic patchwork of barrier islands, salt marshes, tidal flats and large coastal bays, with significant development impacts at Ocean City, Maryland and several beach towns in Delaware. Subdivided by the Conservancy from the much larger Outer Coastal Plain Mixed Forest Province mapped by Bailey, CBY grades into the North Atlantic Coast ecoregion on the south shore of the Delaware Bay, and with the Mid-Atlantic Coastal Plain below the mouth of Chesapeake Bay.​

​ Maps

Landforms, pdf
Managed area ownership, pdf
Element occurrences: natural communities, pdf
Element occurrences: species, pdf
Block size, pdf
Candidate matrix forest blocks, pdf
Candidate matrix forest blocks by ELU group,  pdf
Full portfolio, pdf

Aquatic systems condition summary, pdf
Aquatics: selected streams and matrix blocks, pdf
Condition Analysis, pdf
Estuarine, coastal, and marine significant conservation areas (SCAs), pdf
Historic population growth, pdf
Population growth predictions, pdf 

 

Targets

Species:

 Methods used to assess plant and animal conservation targets - target selection, goal setting, and viability assessment (pdf).  Animals and plants selected for the portfolio are in the species results section (pdf).  

Tabular data:  The three species target tables that follow are in the original report's appendix and will open in excel: Species occurrences summaries for: Delaware, Maryland, Virginia.

Species EOs by subsection (xls) is an extract from occurrences.xls that includes all species targets and their distribution across subsection.  A reference map of CBY subsections is shown above the maps section (here).  

Terrestrial Ecosystems and Communities:
Methods used to assess community conservation targets - target selection, goal setting, and viability assessment are in this pdf.  Communities selected for the portfolio are in the plan report's Terrestrial Ecosystems and Communities Results section (pdf).  The latest national vegetation classification (NVC) for CBY is documented in Internal classification of ecological communities: Terrestrial vegetation of the United States, Chesapeake Bay Lowlands Ecoregion, published July 2003, available as a pdf.  In addition, a key to the vegetation types is included as a separate pdf. 

Tabular data: The terrestrial ecosystems and communities target table (link) is in the original report's appendix and will open in excel.  The tables that follow were assembled to support more detail and flexible examination of target data, in particular for communities, as they are distributed across subsections of the ecoregion.  See the reference map for CBY subsections, above the maps section (here). 

CBY Communities with Goals (xls) compares the expert estimated numbers of associations and subsection distribution of ecosystems with the total number and number of viable examples per subsection included in the Heritage databases.

Community EOs by Subsection (xls) is an extract from occurrences.xls that includes all community targets and their distribution across subsections. 

Matrix Forests:

Methods used to develop and assess matrix-forming ecosystem conservation targets (pdf).  Matrix forest examples selected for the portfolio are in the plan report's Matrix-Forming Ecosystem Results section (pdf).  Ecological Land Units (ELUs) are introducted in the methods chapter, but without much technical description.  Read more about ELUs in the supplementary metadata (.doc). 

 

Tabular data: The following matrix forest target table has been added to the original report.  It describes ELU composition for each matrix block: Chesapeake Bay Matrix Block Assignment (1/21/01).  EOs by Matrix (xls) is a sample extract from occurrences.xls that shows the distribution of all viable species and terrestrial community targets that occur within a portfolio matrix block.  Block reports are pdf documents that summarize all important descriptive and quantitative information about a matrix block.  They were created for the 20 matrix blocks that were chosen in the final portfolio, and can be found here. 

 

Aquatic Systems:

Methods used to assess aquatic conservation targets - target selection, goal setting, and viability assessment (pdf).

 

Aquatic systems selected for the portfolio, in the plan report's Aquatic Results section (pdf).

 

Tabular Data: The four CBY Ecological Drainage Units (EDUs) are Eastern Delmarva, Western Delmarva, Northern MDVA Shore, and Southern MDVA Shore. For these EDUs, the following table has summary data and is ready to print.

 

Estuarine, Coastal, and Marine Systems:

Methods used to assess estuarine, coastal, and marine conservation targets - target selection, goal setting, and viability assessment (pdf). The same section continues with Results of estuarine, coastal, and marine systems selected for the portfolio (pdf). A separate Bibliography is included for marine targets (pdf).

 

Descriptions of Habitat and Species Targets (pdf).  All tables are included in above documents. There are no separate Excel files for marine targets.

 

Spatial Data

 

Dataset name	Definition
	Vector Data
aquashed_rank	Small watersheds with condition ranking attributes
blocks	Road, utility line, railroad, and major hydrography line and polygon features used to build ecosystem blocks; chosen for impact on biodiversity.
cby_subsec	Ecoregion subsection boundaries.
cbyaquasysmacro	EPA 1:100000 RF3 river reaches for USGS Drainage Region 1, with TNC macrohabitat and system attributes
cbyhuc	8-Digit Hydrologic Units for the Coterminous U.S. with TNC EDU attributes.
cbyrf3icmtx	EPA 1:100000 RF3 river reaches for watershed intersecting Chesapeake Bay, with matrix, expert nomination, and portfolio stream attributes.
census	Housing unit density for the U.S. census block groups in 1960-1990 and estimates for 2000-2040.
cerclis	Point sources of pollution: EPA Superfund data used in aquatic condition analysis.
cities	Major cities (over 10,000) in CBY.
counties	Line and polygon boundaries for counties in Northeastern U.S.
dam	National inventory of dams, used in aquatic condition analysis.
dws	Drinking water supplies, used in aquatic condition analysis.
ecmdata	Estuarine, coastal, and marine datasets
ecoregions	Ecoregion boundaries for the Eastern U.S. Source TNC ECS, based on USFS (Keys et al.) subsections and Natural Heritage Program.
gnis	Place names: an automated inventory of physical and cultural geographic features in the U.S.
ifd	Point sources of pollution: Industrial Facilities Discharge used in aquatic condition analysis.
matrix	Viable matrix forest examples in the Chesapeake Bay Lowlands ecoregion.
mgd_areas_draft	DRAFT version of managed areas: All managed lands with a conservation purpose, along with other large state or federally managed lands greater than 500 acres.
mjrds	Major roads: U.S. interstate and state highways and other major thoroughfares.
pcs	Point sources of pollution: Permit Compliance System used in aquatic condition analysis.
rdstmcross	Road stream crossing points.
rf3_sys1rank	EPA 1:100000 RF3 reaches within the TNC Chesapeake Bay Ecoregional Stream System Type 1 group.
rf3_sys5rank	EPA 1:100000 RF3 reaches within the TNC Chesapeake Bay Ecoregional Stream System Type 5 group.
rf3_sys6rank	EPA 1:100000 RF3 reaches within the TNC Chesapeake Bay Ecoregional Stream System Type 6 group.
rf3_sys7rank	EPA 1:100000 RF3 reaches within the TNC Chesapeake Bay Ecoregional Stream System Type 7 group
rf3_sys8rank	EPA 1:100000 RF3 reaches within the TNC Chesapeake Bay Ecoregional Stream System Type 8 group
rf3_sys9rank	EPA 1:100000 RF3 reaches within the TNC Chesapeake Bay Ecoregional Stream System Type 9 group
rf3_sys10rank	EPA 1:100000 RF3 reaches within the TNC Chesapeake Bay Ecoregional Stream System Type 10 group
shedpoly	Local watersheds for each RF3 reach in the sequenced flow network for Chesapeake Bay Ecoregion.
sig_cons_areas	Coastal, estuarine, and marine Significant Conservation Areas in CBY.
states	State boundaries.
triw95	Point sources of pollution: Toxic Release Inventory; Water release in 1995 used in aquatic condition analysis.
	Raster Data
dem30_cby	30 meter Digital Elevation Model: National Elevation Dataset processed to fill cell depressions or 'sinks' that reflect isolated surface error.
elu30	Ecological Land Units: Grid of 30 meter cells that combine the Quaternary geology of the Chesapeake Bay Lowlands and the region's landforms.
cby_nlcd	National Land Cover Dataset of the USGS and EPA for the CBY ecoregion.