Botany

Since its inception as a public garden, the Morris Arboretum has served as a center for botanical research. Research staff at the arboretum study the evolution, phylogenetics, systematics/taxonomy, anatomy and morphology of plants. The Morris Arboretum also has a long-standing research program in floristics, or the study of what plants grow in a certain place in a particular time frame, with a major focus on the flora of Pennsylvania.

Morris Arboretum

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  • Publication
    Nescopeck State Park Inventory of PNDI-Listed Plants and Plant Communities
    (2002-01-01) Rhoads, Ann F; Block, Timothy A
    Nescopeck State Park is a 3,117-acre expanse of forests, former farm fields, and wetlands stretching for about 4 miles in the upper Nescopeck Valley. The park is currently undergoing development of day use areas; an environmental education facility and campground are also planned. Nescopeck does not have any designated natural areas, but several wetlands have been included in special management areas. The park is located in the Ridge and Valley Physiographic Province near the boundary of the Wisconsinan terminal moraine. It contains areas of glacial till and other areas that were not glaciated (Braun 1999a and b; Crowl and Sevon 1980). Bedrock of the entire park is Mauch Chunk Formation (DCNR 1980). Beaver have been a major factor in shaping the wetland communities of the Nescopeck Creek floodplain. A series of present and former beaver ponds is present along the main stem of the Nescopeck and several tributaries. McMaster and McMaster (2001) described a series of successional beaver-determined wetlands in western Massachusetts that show patterns of development very similar to those seen in the Nescopeck valley. While these must be considered temporary or successional in nature, they provide habitat for several rare plants and other species.
  • Publication
    Field Surveys of Aquatic and Terrestrial Plant Species of Special Concern in Eastern Pennsylvania
    (2003-01-01) Block, Timothy A; Rhoads, Ann F
    Aquatic Plant Surveys were carried out at 30 sites and resulted in documentation of 38 occurrences of PNDI-listed vascular plants of which 31 were new and 7 were updates of EOs that had been described previously. Field reports have been submitted to DCNR Bureau of Forestry and PNDI-East. One hundred fifty herbarium specimens were collected and deposited in the herbarium of the Morris Arboretum of the University of Pennsylvania (see complete list attached). Ten of the lakes we surveyed were included in the DEP/EPA water quality sampling program for 2002. We are coordinating with this program in order to be able to compare water quality data with plant inventory data at some future date. We presented two aquatic plant identification workshops to foster an appreciation of the diversity and ecological importance of aquatic plants. We also met with lake residents at many of the lakes we surveyed. We conducted additional field surveys in Montgomery County. Four field visits and numerous telephone and/or email consultations were held regarding PNDI reviews.
  • Publication
    Critical Resources of Bald Mountain Section Lehigh Gorge State Park
    (2013-01-01) Block, Timothy A; Rhoads, Ann F
    The 1539-acre Bald Mountain Section was added to Lehigh Gorge State Park in 2011. It is a forested ridge which buffers the scenic Lehigh River Gorge and affords spectacular views. The tract also includes a pond and associated wetland community created by a dam on Indian Run, a tributary of the Lehigh. Dry oak - heath forest covers the ridge with the exception of the lower slope on the northeast end which supports a hemlock - white pine forest. Over browsing by deer has eliminated the shrub layer and/or created a distinct browse line in much of the site. Wildflower diversity has also been affected. Non-native, invasive species are limited to the vicinity of the former farmstead at the entrance from Lehigh Gorge Drive. A small colony of common reed (Phragmites australis) which has become established in the wetland above the pond should be targeted for removal. Existing woods roads provide good access for hiking including several vistas of the Lehigh Gorge. We recommend a continuation of low intensity use with vehicle access restricted to hunters during deer season. Other than exploring a possible link to the Penn Haven Planes, we do not recommend creation of new trails. A decision to remove the dam on Indian Run should be based on safety concerns. In terms of impact on the vegetation, the wetland plant communities would decline and the adjacent hemlock – white pine forest type would expand down slope. The exposed pond bed would likely be colonized by invasive species such as common reed (Phragmites australis) and reed canary grass (Phalaris arundinacea).
  • Publication
  • Publication
    Surveys of TU Plants, Taxonomic Studies, Pennsylvania Flora Project Web Site, and Environmental Review
    (2001-01-01) Rhoads, Ann F; Block, Timothy A
    In the ongoing effort to refine and improve the scientific accuracy of the Plants of Special concern list work reported here resulted in recommendations for the reclassification of eleven plants. The revised classifications which we recommended were the result of 1) additional field data on current status; 2) new discoveries in the field, 3) adoption of taxonomic revisions reported in recent botanical literature. Our 2000 field work resulted in the documentation of 162 field occurrences at 69 sites. Inflated bladderwort (Utricularia inflata) was added to the flora of Pennsylvania as a result. In order to make information about the state flora more accessible the Pennsylvania Flora Website was redesigned and expanded. The new look was launched in January 2001 at http://www.upenn/edu/paflora. In addition several site reviews were conducted in response to PNDI "hits".
  • Publication
    Field Survey and Status Clarification of PNHP Tentatively Undetermined Plant Species II
    (2010-01-01) Rhoads, Ann F; Block, Timothy A
    Plant status designations of the Pennsylvania Natural Heritage Program include a category of Tentatively Undetermined (TU) for plants believed to be in danger of population decline but which cannot presently be included within another classification due to insufficient data. Plants classified as TU do not receive protection under the Pennsylvania Wild Plant Conservation Act,nor do they trigger environmental review. Using a combination of field surveys and herbarium research we gathered data to support proposed status changes for five species currently listed as TU to Pennsylvania Endangered (PE), Pennsylvania Threatened (PT), or Pennsylvania extirpated (PX). In addition, we evaluated current and historical records for ten additional TU species for which information remains ambiguous and no clear status recommendations can be made at this time. These recommendations were reviewed by the Rare Plant Forum and the Vascular Plants Technical Committee on April 24, 2010. Recommended changes will be incorporated in the revised regulations now under development by DCNR Bureau of Forestry.
  • Publication
    Vegetation of Stockport Forest, Wayne County, Pennsylvania
    (2000-01-01) Rhoads, Ann F; Block, Timothy A
  • Publication
    Characterization and Assessment of the Floristic Resources in Evansburg State Park, Montgomery County, Pennsylvania.
    (2005-01-01) Khan, Nancy R; Rhoads, Ann F; Block, Timothy A
    The central feature of Evansburg State Park is a 12.9 kilometer stretch of Skippack Creek that from a very focused perspective looks much the way it did three centuries ago before European settlers arrived. However, just beyond the narrow fringe of riparian vegetation the landscape is fragmented into small parcels of regenerated forest surrounded by agricultural land, shrub thickets, suburban development, and a well-developed network of roads. The floristic resources of the park are greatly stressed by a variety of competing uses making it difficult for the native vegetation to recover and regain its natural diversity. The lack of baseline documentation for the floristic resources has hindered the ability of land managers to develop a coordinated long-term strategy for the rehabilitation of the native flora. For this study, extensive field data collection occurred simultaneously with community mapping, the development of vegetation classifications, an assessment of the quality of regenerated forests, and an analysis of recovery potential. This report offers a fairly thorough assessment of the botanical and ecological value of the site and provides specific recommendations towards the restoration of natural habitat.
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  • Publication
    Natural Resource Inventory and Management Recommendations Whites Mill Property Salford Township, Montgomery County
    (2003-01-01) Rhoads, Ann F; Block, Timothy A
    The Whites Mill Tract, approximately 100 acres in size, was purchased by Salford Township in 1998 as open space. It is located in a forested landscape comprising about 10,000 acres that stretches across upper Montgomery and Bucks Counties. Because of the extensive contiguous forested area, this region is the target of several efforts to protect the natural resources and its ecological integrity (see Figure 1). The Natural Lands Trust (NLT) and the Montgomery County Conservancy have collaborated to secure conservation easements on the 1700 acre Musser Scout Reservation in the Unami Creek Valley. NLT is also working with Milford Township, Bucks County to extend protection efforts upstream along the Unami and Ridge Valley Creeks. Marlborough Township, Montgomery County recently purchased the Camp Skymount property, which is located about three-quarters mile upstream from Whites Mill pond. NLT's Fulshaw-Craeg Preserve is located approximately one mile downstream. In addition NLT holds conservation easements on a number of private properties in the area.