Rachel Riemann

Landscape characteristics affecting streams in urbanizing regions of the Delaware River Basin (New Jersey, New York, and Pennsylvania, U.S.)

Widespread and increasing urbanization has resulted in the need to assess, monitor, and understand its effects on stream water quality. Identifying relations between stream ecological condition and urban intensity indicators such as impervious surface provides important, but insufficient information to effectively address planning and management needs in such areas. In this study we investigate those specific landscape metrics which are functionally linked to indicators of stream ecological condition, and in particular, identify those characteristics that exacerbate or mitigate changes in ecological condition over and above impervious surface. The approach used addresses challenges associated with redundancy of landscape metrics, and links landscape pattern and composition to an indicator of stream ecological condition across a broad area of the eastern United States. Macroinvertebrate samples were collected during 2000–2001 from forty-two sites in the Delaware River Basin, and landscape data of high spatial and thematic resolution were obtained from photointerpretation of 1999 imagery. An ordination-derived ‘biotic score’ was positively correlated with assemblage tolerance, and with urban-related chemical characteristics such as chloride concentration and an index of potential pesticide toxicity. Impervious surface explained 56% of the variation in biotic score, but the variation explained increased to as high as 83% with the incorporation of a second land use, cover, or configuration metric at catchment or riparian scales. These include land use class-specific cover metrics such as percent of urban land with tree cover, forest fragmentation metrics such as aggregation index, riparian metrics such as percent tree cover, and metrics related to urban aggregation. Study results indicate that these metrics will be important to monitor in urbanizing areas in addition to impervious surface.

Ohio forests: 2006

This report summarizes annual forest inventories conducted in Ohio from 2001 to 2006 by the Northern Research Stations Forest Inventory and Analysis unit. Ohios forest land covers 7.9 million acres or 30 percent of the States land area, changing little in forest land area since 1991. Of this land, 5.8 million acres (73 percent) are held by family forest owners. The current growing-stock inventory is 12.3 billion cubic feet--2 percent more than in 1991--and averages 1,603 cubic feet per acre. Yellow-poplar continues to lead in volume followed by red and sugar maples. Since 1991, the saw log portion of growing-stock volume has increased by 35 percent to 41 billion board feet. In the latest inventory, net growth exceeded removals for all major species except elm.

Integrating forest inventory and analysis data into a LIDAR-based carbon monitoring system

BackgroundForest Inventory and Analysis (FIA) data may be a valuable component of a LIDAR-based carbon monitoring system, but integration of the two observation systems is not without challenges. To explore integration methods, two wall-to-wall LIDAR-derived biomass maps were compared to FIA data at both the plot and county levels in Anne Arundel and Howard Counties in Maryland. Allometric model-related errors were also considered.ResultsIn areas of medium to dense biomass, the FIA data were valuable for evaluating map accuracy by comparing plot biomass to pixel values. However, at plots that were defined as “nonforest”, FIA plots had limited value because tree data was not collected even though trees may be present. When the FIA data were combined with a previous inventory that included sampling of nonforest plots, 21 to 27% of the total biomass of all trees was accounted for in nonforest conditions, resulting in a more accurate benchmark for comparing to total biomass derived from the LIDAR maps. Allometric model error was relatively small, but there was as much as 31% difference in mean biomass based on local diameter-based equations compared to regional volume-based equations, suggesting that the choice of allometric model is important.ConclusionsTo be successfully integrated with LIDAR, FIA sampling would need to be enhanced to include measurements of all trees in a landscape, not just those on land defined as “forest”. Improved GPS accuracy of plot locations, intensifying data collection in small areas with few FIA plots, and other enhancements are also recommended.

Forest fragmentation in Massachusetts, USA: a town-level assessment using Morphological spatial pattern analysis and affinity propagation

Forest fragmentation has been studied extensively with respect to biodiversity loss, disruption of ecosystem services, and edge effects although the relationship between forest fragmentation and human activities is still not well understood. We classified the pattern of forests in Massachusetts using fragmentation indicators to address these objectives: 1) characterize the spatial pattern of forest fragmentation in Massachusetts towns using Morphological Spatial Pattern Analysis (MSPA); and (2) identify regional trends using archetypal towns in relation to town history, geography and socioeconomic characteristics. Six fragmentation indicators were calculated using MSPA for each town to represent patterns and processes of fragmentation. We then used these indicators and the proportion of forested land to group towns across Massachusetts with similar patterns of fragmentation. Six representative towns typify different types of forest fragmentation, and illustrate the commonalities and differences between different fragmentation types. The objective selection of representative towns suggests that they might be used as the target of future studies, both in retrospective studies that seek to explain current patterns and in analyses that predict future fragmentation trends.

The Forests of Southern New England, 2007: A report on the forest resources of Connecticut, Massachusetts, and Rhode Island

This report summarizes the results of the fifth forest inventory of the forests of Southern New England, defined as Connecticut, Massachusetts, and Rhode Island, conducted by the U.S. Forest Service, Forest Inventory and analysis program. Information on forest attributes, ownership, land use change, carbon, timber products, forest health, and statistics and quality assurance of data collection are included. There are 5.1 million acres of forest land across the region; 60 percent of this forest land is in Massachusetts, 33 percent in Connecticut, and 7 percent in Rhode Island. This amount has decreased by 5 percent since the last inventory was completed in 1998. There are 2.6 billion trees on this forest land that have total volume of 12.6 billion cubic feet. Red maple and eastern white pine are the most common species in terms of both numbers of trees and volume. Fifty percent of the forest land is classified as the oak-hickory forest type.

West Virginia's Forests 2008

The first full annual inventory of West Virginias forests reports 12.0 million acres of forest land or 78 percent of the States land area. The area of forest land has changed little since 2000. Of this land, 7.2 million acres (60 percent) are held by family forest owners. The current growing-stock inventory is 25 billion cubic feet--12 percent more than in 2000--and averages 2,136 cubic feet per acre. Yellow-poplar continues to lead in volume followed by white and chestnut oaks. Since 2000, the saw log portion of growing-stock volume has increased by 23 percent to 88 billion board feet. In the latest inventory, net growth exceeded removals for all major species. Detailed information on forest inventory methods and data quality estimates is included in a DVD at the back of this report. Tables of population estimates and a glossary are also included.

Comparative assessment of methods for estimating tree canopy cover across a rural-to-urban gradient in the mid-Atlantic region of the USA

Tree canopy cover significantly affects human and wildlife habitats, local hydrology, carbon cycles, fire behavior, and ecosystem services of all types. In addition, changes in tree canopy cover are both indicators and consequences of a wide variety of disturbances from urban development to climate change. There is growing demand for this information nationwide and across all land uses. The extensive inventory plot system managed by the USDA Forest Service Forest Inventory and Analysis (FIA) offers a unique opportunity for acquiring unbiased tree canopy cover information across broad areas. However, the estimates it produces had not yet been examined for comparative accuracy with other sources. In this study, we compared four different methods readily available and with significant potential for application over broad areas. The first two, field-collected and photointerpreted, are currently acquired by FIA on approximately 44,000 plots annually nationwide. The third method is a stem-mapping approach that models tree canopy cover from variables regularly measured on forested plots and is efficient enough to calculate nationwide. The fourth is a Geographic-Object-Based Image Analysis (GEOBIA) approach that uses both high-resolution imagery and leaf-off LiDAR data and has reported very high accuracies and spatial detail at state-wide levels of application. Differences in the spatial and temporal resolution and coverage of these four datasets suggest that they could provide complementary information if their relationships could be better understood. Plot- and county-level estimates of tree canopy cover derived from each of the four data sources were compared for 11 counties in Maryland, Pennsylvania, and West Virginia across a range of urbanization levels. We found high levels of systematic agreement between field and photointerpreted, stem-mapped and field, photointerpreted and GEOBIA estimates. In several cases, the relationship changed with the level of tree canopy cover. GEOBIA produced the highest tree cover estimates of all the methods compared. Results are discussed with respect to known differences between the methods and ground conditions found in both forest and nonforest areas.

Ohio's Forests 2011

This report summarizes the second full cycle of annual inventories, 2007-2011, of Ohios forests by the Forest Inventory and Analysis unit of the Northern Research Station in cooperation with the Ohio Department of Natural Resources, Division of Forestry. Since 2006, forest land increased by 2.1 percent and currently totals 8.1 million acres. Net volume of live trees on forest land increased by 7 percent totaling 15.9 billion cubic feet. Most stands are dominated by large trees, 66 percent are in sawtimber-size stands, although most stands are less than fully stocked with growing-stock trees. Annual growth outpaced removals by a ratio of 2.2:1. This report includes additional information on forest attributes, land-use change, carbon, and forest health. The included DVD contains 1) descriptive information on methods, statistics, and quality assurance of data collection, 2) a glossary of terms, 3) tables that summarize quality assurance, 4) a core set of tabular estimates for a variety of forest resources, and 5) a Microsoft Access database that represents an archive of data used in this report, with tools that allow users to produce customized estimates.

Pennsylvania's Forests, 2009

The second full annual inventory of Pennsylvanias forests reports a stable base of 16.7 million acres of forest land. Northern hardwoods and mixed-oak forest-type groups account for 54 and 32 percent of the forest land, respectively. The States forest land averages about 61 dry tons of wood per acre and almost 6,500 board feet (International ¼-inch rule) per acre on timberland. The ratio of average annual net growth-to-removals for growing-stock trees on timberland was about 2:1. Additional information is presented on forest land use, forest resources, forest sustainability, forest health (including regeneration), and timber products. Detailed information on forest inventory methods and data quality estimates are included in a DVD at the back of the report. Tables of population estimates and a glossary are also included.

Delaware's Forests 2008

The fifth full inventory of Delawares forests reports an 8 percent decrease in the area of forest land to 352,000 acres, which cover 28 percent of the States land area and has a volume of approximately 2,352 cubic feet per acre. Twenty-one percent of the growing-stock volume is red maple, followed by sweetgum (13 percent), and loblolly pine (12 percent). All species of oaks combined account for 24 percent of the volume. Red maple is the most abundant species in terms of number of trees and the population had been rising through the 1980s and 1990s, but current data show little change since 1999. Oak species and loblolly pine decreased in numbers of trees and volumes. Seventy-three percent of forest land consists of large-diameter trees and 10 percent is in the small-diameter stand-size classes. Average annual growth as a percentage of total growing-stock volume increased from 2.3 to 3.9 percent between 1999 and 2008, while removals and mortality changed little. Additional information on forest attributes, land-use change, carbon, timber products, and forest health is presented in this report. A DVD included in the report provides information on sampling techniques, estimation procedures, a glossary, tables of population estimates, raw data, and a data summarization and reporting tool.