County Natural Heritage Inventory
Since 1989, PNHP staff have been conducting inventories of the
ecological resources in each county of the Commonwealth. Nearing
the completion of the first round of inventories, a new phase of
CNHIs is beginning. Read more about county inventories.
Pennsylvania Rare Plant Forum
The Rare Plant Forum is a function of the Vascular Plant Technical Committee
of the Pennsylvania Biological Survey, and for over twenty-five years has served
in an advisory role to the Commonwealth of Pennsylvania for issues related to the
conservation of the native flora of Pennsylvania. In addition to discussing
proposed changes to the list of Plants of Special Concern in Pennsylvania (POSCIP),
there are usually a few related presentations. Read more about the Pennsylvania Rare Plant Forum.
Bryophyte and Lichen Indicators
Bryophytes (mosses, liverworts, and hornworts) and lichens grow
in many different habitats in close association with their substrates.
This species/substrate relationship results in sensitivity to changes
at the microclimatic level. Taking the cue from recent research, we
are comparing the bryophyte and lichen diversity in forested areas
receiving different levels of disturbance with Miller Run Natural
Area in north central Pennsylvania. The goals of the project are to
determine differences in bryophyte and lichen diversity and identify
potential species indicators of high quality forest habitats.
Submerged Aquatic Vegetation
Submerged aquatic vegetation (SAV) refers to a group
of plants that grow entirely underwater; although some may have additional
floating leaves. These plants have important ecological roles in aquatic systems.
Dense patches of aquatic plants provide protection for small juvenile fish and serve
as an attachment surface for snails and other invertebrates, while decomposing SAV
provides a food source for bottom-dwelling organisms. SAV beds also reduce
turbidity by slowing the flow of water which allows sediment to settle out,
and their roots help stabilize the substrate. PNHP staff mapped SAV in the
upper Delaware River for the National Park Service, revisiting many of the
same sites that were documented in the early 1990s. The results of the work
will help the Park Service as well as others involved in the management of
the basin to assess the health of the river.
Pennsylvania Game Lands Management Tool
The Pennsylvania Game Lands Management Tool (PGLMT) is an
interagency effort to improve management planning for rare, threatened, and
endangered species on Pennsylvania’s State Game Lands. For this project,
PNHP has collected new data for populations of state listed plants and animals
on state game lands and prepared management plans for these species. We
have also mapped ecologically important habitats for state and federally
listed species on state game lands. When completed, this tool will
streamline and simplify conservation planning by balancing the habitat
management goals of PGC with the conservation needs of Pennsylvania’s
rare, threatened, and endangered species.
Northeastern Bulrush Monitoring
Northeastern bulrush (Scirpus ancistrochaetus) is a federally and
state endangered plant that grows in vernal pools throughout the central and eastern
sections of the state. Pennsylvania represents a stronghold for this plant species
since the majority of all known locations are found within the Commonwealth. To
assess the health of the populations within Pennsylvania, PNHP biologists are
working with the U.S. Fish and Wildlife Service and DCNR to monitor Scirpus
populations and to study the genetics of those populations to better understand
the diversity of the species throughout its range in the northeastern United States.
Bureau of Forestry Surveys
The Pennsylvania Bureau of Forestry (BOF) owns and manages
over 2.2 million acres of land in the state. Although a great deal of
information concerning rare species and natural communities exist for
BOF lands, there are still many areas that have not been surveyed. Additionally,
there are many older records for plant and animal populations that need to be
updated. Much of our work has focused on the large forests of north central
Pennsylvania, particularly in the regions experiencing development pressure
from the natural gas industry, where species like the timber rattlesnake and
northern water shrew are particularly abundant but in need of greater survey,
This information will aid the Bureau in effectively managing the state forest
system for multiple uses while taking into account some of the state’s most
unique plant and animal resources.
One of Pennsylvania’s rare violets, the great-spurred violet
(Viola selkirkii), is associated with rich forests in northern Pennsylvania.
PNHP has undertaken a project to better understand the relationship of great-spurred
violet to the specific natural communities and environmental conditions with which
it is associated. We hope to expand the records we have for great-spurred violet and
to use information from habitat assessments to improve conservation planning for
PNHP has begun an EPA-funded study to describe and document the
vegetation and natural communities associated with riparian areas of headwater streams
across the state. The riparian zone is the transition area between where a stream
channel ends and terrestrial communities begin. Native plants that grow in riparian
areas along waterways protect the stream bank from erosion, regulate water temperatures,
and provide food and shelter for a variety of wildlife both in and along the stream.
These areas can be damaged by disturbances that occur near streams or within the
upper watersheds where headwater streams are found. Information from this study
will be used to update the natural plant community classification and assist DEP
with mitigation strategies.
Delaware River Mussels
PNHP aquatic ecologists are surveying the Delaware River basin for
two endangered mussel species; the state endangered eastern pearlshell (Margaritifera
margaritifera) and the federally endangered dwarf wedgemussel (Alasmidonta heterodon).
The eastern pearlshell can live 100 years or more in typically small, coldwater streams
that support brown trout and other salmonids. Pennsylvania waters are thought to be the
southern-most extent of its range in North America. The dwarf wedgemussel also prefers
cool, clean waters in North American east coast streams. Characteristics that make dwarf
wedgemussel vulnerable to threats include a relatively short life span (about 12 years),
low rates of reproduction, and limited dispersal. Eastern pearlshell and dwarf wedgemussel
have both seen dramatic declines from their historic populations. In an effort to discover
previously unknown populations, this project will inventory potential habitats in the
Delaware River basin to better understand the distribution of these two rare mussels