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  • Worcester, Massachusetts, United States

John Rogan

Clark University, Geography, Faculty Member
Background/Question/Methods The objective of this paper is to quantify gains and losses in urban forest ecosystem services following tree removal and subsequent replanting. Increasingly common threats to urban green space, such as... more
Background/Question/Methods The objective of this paper is to quantify gains and losses in urban forest ecosystem services following tree removal and subsequent replanting. Increasingly common threats to urban green space, such as invasive pest outbreak, new urban development, and severe weather events can rapidly change forest structure, reducing the ecosystem services that benefit urban residents. The Burncoat and Greendale neighborhoods of Worcester, MA were thickly tree-lined prior to the infestation of Asian Longhorned Beetle (ALB) (Anophlophora glabripennis). ALB eradication managers extensively removed host trees in the area and subsequently planted non-host trees from 2008 to 2012. Changes in ecosystem services resulting from tree loss and replanting are quantified in this study using tree removal and tree planting inventories and i-Tree Street software. Results/Conclusions Tree removal from 2008 to 2010 caused the loss of 8,593 trees, primarily large and medium broadleaf sp...
This study assesses the performance of five Machine Learning Algorithms (MLAs) in a chronically modified mixed deciduous forest in Massachusetts (USA) in terms of their ability to detect selective timber logging and to cope with deficient... more
This study assesses the performance of five Machine Learning Algorithms (MLAs) in a chronically modified mixed deciduous forest in Massachusetts (USA) in terms of their ability to detect selective timber logging and to cope with deficient reference datasets. Multitemporal Landsat Enhanced Thematic Mapper- plus (ETM+) imagery is used to assess the performance of three Artificial Neural Networks - Multi-Layer Perceptron,
Research Interests:
ABSTRACT
This paper presents preliminary results of research to improve upon an existing operational forest change detection monitoring strategy in California. Comparisons were. made between Landsat 5 TM and Landsat 7 ETM scene normalization... more
This paper presents preliminary results of research to improve upon an existing operational forest change detection monitoring strategy in California. Comparisons were. made between Landsat 5 TM and Landsat 7 ETM scene normalization techniques (absolute versus, relative). Prior to normalization, scenes containing wildfire smoke plumes were successfully corrected using a space-varying haze equalization algorithm. Simple dark object subtraction provided improved performance over relative (pseudo-invariant feature) approaches. A decision tree classifier produced high change map overall accuracy (86%) for five categories of forest cover change
Several remote sensing techniques have been used successfully to map the areas of wildfire burn scars. Burn severity mapping, however, presents a suite of problems, caused by spectral confusion between vegetation affected by surface fire... more
Several remote sensing techniques have been used successfully to map the areas of wildfire burn scars. Burn severity mapping, however, presents a suite of problems, caused by spectral confusion between vegetation affected by surface fire and unburned vegetation, between moderately burned vegetation and sparse vegetation, and between burned shaded and unburned shaded vegetation. A single date Landsat-7 Enhanced Thematic Mapper image was used to map five burn severity classes in two areas affected by wildfire in southern California in June 1999. Spectral mixture analysis (SMA), using four reference endmembers (vegetation, soil, shade, nonphotosynthetic vegetation) and a single (charcoal-ash) image endmember, was used to enhance the image prior to supervised classification of burn severity. SMA provided a robust technique for mapping fire-affected areas due to its ability to extract subpixel information and minimize the effects of topography on single date satellite data. Overall kappa classification accuracy was high (0.81 and 0.72, respectively) for the burned areas, using five burn severity classes. Individual severity class accuracies ranged from 0.53 to 0.94