Filters: Tags: canopy dieback (X)
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We analyzed very-high-resolution imagery to assess status of Metrosideros polymorpha forests across an 83,603 hectare study area that experienced extensive canopy dieback in the 1970s on the eastern side of the island of Hawaii. Using GIS we generated 1170 virtual vegetation plots with a 100 m radius; 541 plots in areas mapped in 1977 with trees dead or mostly defoliated (dieback), and 629 plots in adjacent wet forest habitat, previously mapped as non-dieback condition. In each plot we estimated the percent of M. polymorpha trees dead or mostly defoliated, and percent of trees with healthy crowns. These results were combined with habitat data to produce a spatial model depicting probability of canopy dieback within...
Categories: Data;
Tags: Hawaii,
Metrosideros polymorpha,
biota,
canopy dieback,
field inventory and monitoring,
Several previously published reports and geographic information system (GIS) data layers were used to code information on site attributes for each assessment plot using the spatial join tool in ArcMap. This information was used for an analysis of dieback and non-dieback habitat characteristics. The results of this analysis are presented in this table which depicts the probability of heavy to severe canopy dieback occurring at some time at a particular 30 x 30 m pixel location within the study area.
Categories: Data;
Tags: Hawaii,
Metrosideros polymorpha,
analytical modeling,
biota,
canopy dieback,
These data are satellite image-derived, classification maps of tamarisk (Tamarisk spp.) along the Colorado River in Grand Canyon National Park from river km 315 to 363, approximately from Parashant Canyon to Diamond Creek tributaries. The classification maps are published in TIF raster format. Two maps are published: 1) a classification of healthy, defoliated, and tamarisk canopy dieback from the tamarisk beetle (Diorhabda carinulata) in May 2019, and 2 a classification of healthy and beetle-impacted tamarisk in August 2019. Tamarisk was mapped using a Spectral Angle Mapper supervised classification derived from 2 m resolution, multispectral WorldView-2 imagery, with an overall accuracy of 80.0% in May 2019 and...
This dataset describes the boundary of the study area used to analyze regeneration and change in status of native ohia forests in the wet habitat on the eastern side of the island of Hawaii. This area includes forests that were heavily impacted by landscape-level canopy dieback in the 1970s as well as forests that were not affected with tree canopy death or defoliation.
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Hawaii,
Metrosideros polymorpha,
biota,
canopy dieback,
ohia,
This shapefile describes the canopy status and distribution of of ohia (Metrosideros polymorpha) forests on the eastern side of the island relative to a landscape-scale canopy dieback that impacted this area in the 1970s.
Categories: Data;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: Hawaii,
Metrosideros polymorpha,
biota,
canopy dieback,
ohia
Decline of riparian forests has been attributed to hydrologic modifications to river flows. However, little is known about the physiological and structural adjustments of riparian forests subject to modified flow regimes, and the potential for forest restoration using historic flow regimes is poorly understood. In this paired river study, we compared hydrology, water relations, and forest structure in cottonwood-dominated floodplains of the regulated Green River to those of the unregulated Yampa River. We measured floodplain groundwater levels, soil water availability, cottonwood xylem pressure (Ψxp), and leaf-level stomatal conductance (gs) to assess current impacts of river regulation on the water status of adult...
Categories: Publication;
Types: Citation,
Journal Citation;
Tags: Ecosystems,
Springer New York,
canopy dieback,
cottonwood,
riparian,
We analyzed very-high-resolution imagery to assess status of Metrosideros polymorpha forests across an 83,603-hectare study area that experienced extensive canopy dieback in the 1970s on the eastern side of the island of Hawaii. Using GIS we generated 1,170 virtual vegetation plots with a 100-m radius; 541 plots in areas mapped in 1977 with trees dead or mostly defoliated (dieback), and 629 plots in adjacent wet forest habitat, previously mapped as non-dieback condition. In each plot we estimated the percent of M. polymorpha trees dead or mostly defoliated, and percent of trees with healthy crowns. These results were combined with habitat data to produce a spatial model depicting probability of canopy dieback within...
This data set includes an accuracy assessment of the repeatability of identifying heavy to severe tree canopy dieback in virtual plots located within the Ohia Dieback 83,603 hectare study area.
Categories: Data;
Tags: Hawaii,
Metrosideros polymorpha,
accuracy assessment,
biota,
canopy dieback,
This data set provides the locations of the ground-based vegetation plots that have been used to assess the status of the ohia forests on the eastern side of the island of Hawaii following a landscape-level canopy dieback event that occurred in this area in the 1970s. These plots have been resurveyed several times and the results summarized by Boehmer et al. 2013.
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