Research Interests:

Description

>>Using Aerial Photography to 3-dimensionally map and monitor vegetation, soil erosion, and surface hydrology on rangeland landscapes
>>Building web-based platforms for scientific knowledge exchange focusing on spatial explicit information

latest article added on December 2013

ArticleFirst AuthorPublished
Using spatial statistics and point-pattern simulations to assess the spatial dependency between greater sage-grouse and anthropogenic featuresGillan, Jeffrey K.2013

Using spatial statistics and point-pattern simulations to assess the spatial dependency between greater sage-grouse and anthropogenic features

Keywords

Centrocercus urophasianus, Monte Carlo, pair correlation function, point pattern, Ripley’s K, sage-grouse, spatial statistics

Abstract

The greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse), a candidate species for listing under the Endangered Species Act, has experienced population declines across its range in the sagebrush (Artemisia spp.) steppe ecosystems of western North America. One factor contributing to the loss of habitat is the expanding human population with associated development and infrastructure. Our objective was to use a spatial-statistical approach to assess the effect of roads, power transmission lines, and rural buildings on sage-grouse habitat use. We used the pair correlation function (PCF) spatial statistic to compare sage-grouse radiotelemetry locations in west-central Idaho, USA, to the locations of anthropogenic features to determine whether sage-grouse avoided these features, thus reducing available habitat. To determine significance, we compared empirical PCFs with Monte Carlo simulations that replicated the spatial autocorrelation of the sampled sage-grouse locations. We demonstrate the implications of selecting an appropriate null model for the spatial statistical analysis by comparing results using a spatially random and a clustered null model. Results indicated that sage-grouse avoided buildings by 150 m and power transmission lines by 600 m, because their PCFs were outside the bounds of a 95% significance envelope constructed from 1,000 iterations of a null model. Sage-grouse exhibited no detectable avoidance of major and minor roads. The methods used here are broadly applicable in conservation biology and wildlife management to evaluate spatial relationships between species occurrence and landscape features. Our results can directly inform planning of infrastructure and other development projects in or near sage-grouse habitat.

Authors

Gillan, Jeffrey K., Strand, Eva K., Karl, Jason W., Reese, Kerry P. and Laninga, Tamara

Year Published

2013

Publication

Wildlife Society Bulletin

Locations
DOI

10.1002/wsb.272

Geographic searching for ecological studies: a new frontierKarl, Jason W.2013

Geographic searching for ecological studies: a new frontier

Keywords

No keywords available

Abstract

No abstract available

Authors

Karl, Jason W., Gillan, Jeffrey K. and Herrick, Jeffrey E.

Year Published

2013

Publication

Trends in Ecology & Evolution

Locations
    DOI

    10.1016/j.tree.2013.05.001

    Sage-grouse Habitat in Idaho: A Practical Guide For Land Owners and ManagersGillan, Jeffrey K.2010

    Sage-grouse Habitat in Idaho: A Practical Guide For Land Owners and Managers

    Keywords

    No keywords available

    Abstract

    The greater sage-grouse is a species in decline across the western United States, including Idaho. As implied by the name, greater sage-grouse depend on sagebrush dominated landscapes for their forage, cover, nesting habitat, and ultimate survival. The deterioration of sagebrush landscapes in the West has been crucial factor in the decline of the greater sage-grouse, which is currently a candidate species under the federal Endangered Species Act. State and federal government land managers, researchers, private landowners, and concerned citizens are leading efforts to conserve this species in Idaho. This book is largely an illustrated synthesis of the 2006 Conservation Plan for Greater Sage-grouse in Idaho, produced by the Idaho Sage-grouse Advisory Committee. Although the information in the 2006 Conservation is based on scientific research, the guidebook is meant to extend what is known about sage-grouse and their habitat to land owners and managers but is not meant to be cited as a science document itself. The intent of this guidebook is to help land owners and managers recognize characteristics of productive and unfavorable sage-grouse habitat throughout the different life stages, prompting better informed approaches to management and conservation. The focus is clearly on ranching, as opposed to other land use activities, because livestock grazing is the major land use that occurs on sage-grouse habitat. The guidebook provides information to recognize and evaluate sage-grouse habitat, but does not recommend specific grazing or land management practices. Those who manage and live within sagebrush landscapes can play a significant role in conserving sage-grouse and the habitat the depend on. This book is just a small part of the larger commitment that is being made to conserve this species.

    Authors

    Gillan, Jeffrey K. and Strand, Eva K.

    Year Published

    2010

    Publication

    Idaho College of Natural Resources

    Locations
    Additional Information:

    http://www.webpages.uidaho.edu/range/pubs/sage-grouse_guide.pdf

    Spatial patterns of grassland-shrubland state transitions: a 74 year record on grazed and protected areasBrowning, Dawn2014

    Spatial patterns of grassland-shrubland state transitions: a 74 year record on grazed and protected areas

    Keywords

    point pattern analysis, spatial ecology, pair correlation function, Ripley’s K, Moran’s I, spatial autocorrelation, LISA, livestock exclusion, Sonoran Desert, Prosopis velutina

    Abstract

    Tree and shrub abundance has increased in many grasslands, causing changes in ecosystem carbon and nitrogen pools that are related to patterns of woody plant distribution. However, with regard to spatial patterns, little is known about (i) how they develop; (ii) how they are influenced by grazing; or (iii) the extent to which intraspecific interactions dictate them. We addressed these questions by quantifying changes in the spatial distribution of Prosopis velutina (mesquite) shrubs over 74 years on grazed and protected grasslands. Livestock are effective agents of mesquite dispersal and mesquite has lateral roots extending well beyond its canopy. We therefore hypothesized that mesquite distributions would be (a) random on grazed areas and clustered on protected areas; and (b) that clustered or random distributions at early stages of encroachment would give way to regular distributions as stands matured and density-dependent interactions intensified. Assessments in 1932, 1948 and 2006 supported the first hypothesis, but we found no support for the second. In fact, clustering intensified with time on the protected area and the pattern remained random on the grazed site. Although shrub density increased on both areas between 1932 and 2006, we saw no progression toward a regular distribution indicative of density-dependent interactions. We propose that processes related to seed dispersal, grass-shrub seedling interactions, and hydrological constraints on shrub size interact to determine vegetation structure in grassland-to-shrubland state changes with implications for ecosystem function and management

    Authors

    Browning, Dawn, Franklin, Janet, Archer, Steven R., Gillan, Jeffrey K. and Guertin, D.Phillip

    Year Published

    2014

    Publication

    Ecological Applications

    Locations
    DOI

    10.1890/13-2033.1

    This article contributed by:

    Ecological Society of America

    Modeling Vegetation Heights from High Resolution Stereo Aerial Photography: An Application for Broad-Scale Rangeland MonitoringGillan, Jeffrey K.2014

    Modeling Vegetation Heights from High Resolution Stereo Aerial Photography: An Application for Broad-Scale Rangeland Monitoring

    Keywords

    rangeland monitoring, photogrammetry, vegetation height, digital terrain model, remote sensing

    Abstract

    Vertical vegetation structure in rangeland ecosystems can be a valuable indicator for assessing rangeland health and monitoring riparian areas, post-fire recovery, available forage for livestock, and wildlife habitat. Federal land management agencies are directed to monitor and manage rangelands at landscapes scales, but traditional field methods for measuring vegetation heights are often too costly and time consuming to apply at these broad scales. Most emerging remote sensing techniques capable of measuring surface and vegetation height (e.g., LiDAR or synthetic aperture radar) are often too expensive, and require specialized sensors. An alternative remote sensing approach that is potentially more practical for managers is to measure vegetation heights from digital stereo aerial photographs. As aerial photography is already commonly used for rangeland monitoring, acquiring it in stereo enables threedimensional modeling and estimation of vegetation height. The purpose of this study was to test the feasibility and accuracy of estimating shrub heights from high-resolution (HR, 3-cm ground sampling distance) digital stereo-pair aerial images. Overlapping HR imagery was taken in March 2009 near Lake Mead, Nevada and 5-cm resolution digital surface models (DSMs) were created by photogrammetric methods (aerial triangulation, digital image matching) for twenty-six test plots. We compared the heights of individual shrubs and plot averages derived from the DSMs to field measurements. We found strong positive correlations between field and image measurements for several metrics. Individual shrub heights tended to be underestimated in the imagery, however, accuracy was higher for dense, compact shrubs compared with shrubs with thin branches. Plot averages of shrub height from DSMs were also strongly correlated to field measurements but consistently underestimated. Grasses and forbs were generally too small to be detected with the resolution of the DSMs. Estimates of vertical structure will be more accurate in plots having low herbaceous cover and high amounts of dense shrubs. Through the use of statistically derived correction factors or choosing field methods that better correlate with the imagery, vegetation heights from HR DSMs could be a valuable technique for broad-scale rangeland monitoring needs.

    Authors

    Gillan, Jeffrey K., Karl, Jason W., Duniway, Michael and Elaksher, Ahmed

    Year Published

    2014

    Publication

    Journal of Environmental Management

    Locations
    DOI

    10.1016/j.jenvman.2014.05.028

    Atlas of YellowstoneMarcus, W. Andrew2012

    Atlas of Yellowstone

    Keywords

    No keywords available

    Abstract

    No abstract available

    Authors

    Marcus, W. Andrew, Meacham, James, Rodman, Ann W. and Steingisser, Alethea Y.

    Year Published

    2012

    Publication

    Atlas of Yellowstone

    Locations
    Additional Information:

    http://atlasofyellowstone.com/

    Interpretation of high-resolution imagery for detecting woodland cover composition change after fuels reduction treatmentsKarl, Jason W.2014

    Interpretation of high-resolution imagery for detecting woodland cover composition change after fuels reduction treatments

    Keywords

    image interpretation, rangeland monitoring, remote sensing, high-resolution, land cover, change detection

    Abstract

    The use of very high resolution (VHR; ground sampling distances < ~5cm) aerial imagery to estimate site vegetation cover and to detect changes from management has been well documented. However, as the purpose of monitoring is to document change over time, the ability to detect changes from imagery at the same or better level of accuracy and precision as those measured in situ must be assessed for image-based techniques to become reliable tools for ecosystem monitoring. Our objective with this study was to quantify the relationship between field-measured and image-interpreted changes in vegetation and ground cover measured one year apart in a savanna with increased woody vegetation cover in southern Utah, USA. The study area was subject to a variety of fuel removal treatments between 2009 and 2010. We measured changes in plant community composition and ground cover along transects in a control area and three different treatments prior to and following three woody removal. We compared these measurements to vegetation composition and change based on photo-interpretation of ~4 cm ground sampling distance imagery along similar transects. Estimates of cover were similar between field-based and image-interpreted methods in 2009 and 2010 for woody vegetation, no vegetation, herbaceous vegetation and litter (including woody litter). Image-interpretation slightly overestimated cover for woody vegetation and no-vegetation classes (average difference between methods of 1.34% and 5.85%) and tended to underestimate cover for herbaceous vegetation and litter (average difference of -5.18% and 0.27%), but the differences were significant only for litter cover in 2009. Level of agreement between the field-measurements and image-interpretation was good for woody vegetation and no-vegetation classes (r between 0.47 and 0.89), but generally poorer for herbaceous vegetation and litter (r between 0.18 and 0.81) likely due to differences in image quality by year and the difficulty in discriminating fine vegetation and litter in imagery. Our results show that image interpretation to detect vegetation changes has utility for monitoring fuels reduction treatments in terms of woody vegetation and bare ground. The benefits of this technique are that it provides objective and repeatable measurements of site conditions that could be implemented relatively inexpensively and easily without the need for highly specialized software or technical expertise. Perhaps the biggest limitations of image interpretation to monitoring fuels treatments are the difficulty in challenges in estimating litter and herbaceous vegetation cover and the sensitivity of herbaceous cover estimates to image quality and shadowing.

    Authors

    Karl, Jason W., Gillan, Jeffrey K., Barger, Nichole N., Herrick, Jeffrey E. and Duniway, Michael

    Year Published

    2014

    Publication

    Ecological Indicators

    Locations
    DOI

    10.1016/j.ecolind.2014.05.017

    Discovering Ecologically Relevant Knowledge from Published Studies through Geosemantic SearchingKarl, Jason W.2013

    Discovering Ecologically Relevant Knowledge from Published Studies through Geosemantic Searching

    Keywords

    georeferencing, metadata, semantic search, spatial distribution, knowledge discovery

    Abstract

    It is easier to search the globe for research on the genes of a local plant than it is to find local research on that plant’s ecology. As a result, ecologists are often unaware of published local research and unlikely to find relevant studies from similar environments worldwide. Location information in ecological studies can be harnessed to enable geographic knowledge searches and could be standardized to make searches more fruitful. To demonstrate this potential, we developed the JournalMap Web site (www.journalmap.org). Easy access to geographic distributions of knowledge opens new possibilities for using ecological research to detect and interpret ecological patterns, evaluate current ecological knowledge, and facilitate knowledge creation. We call on journals and publishers to support standard reporting of study locations in publications and metadata, and we advocate georeferencing past studies.

    Authors

    Karl, Jason W., Herrick, Jeffrey E., Unnasch, Robert, Gillan, Jeffrey K., Ellis, Erle C., Lutters, Wayne G. and Martin, Laura J.

    Year Published

    2013

    Publication

    BioScience

    Locations
      DOI

      10.1525/bio.2013.63.8.10

      Sea Kayak Guiding in the Florida KeysGillan, Jeffrey K.2004

      Sea Kayak Guiding in the Florida Keys

      Keywords

      No keywords available

      Abstract

      No abstract available

      Authors

      Gillan, Jeffrey K.

      Year Published

      2004

      Publication

      Hawks Cay Resort, Duck Key, Florida

      Locations
      GIS Inventory of Petersburg National Battlefield EarthworksGillan, Jeffrey K.2008

      GIS Inventory of Petersburg National Battlefield Earthworks

      Keywords

      No keywords available

      Abstract

      No abstract available

      Authors

      Gillan, Jeffrey K.

      Year Published

      2008

      Publication

      Petersburg National Battlefield

      Locations

      Recent Articles

      Spatial Patterns of Grassland-Shrubland State Transitions: a 74 Year Record on Grazed and Protected Areas

      by Browning, Dawn, Franklin, Janet, Archer, Steven R., Gillan, Jeffrey K. and Guertin, D.Phillip

      Tree and shrub abundance has increased in many grasslands, causing changes in ecosystem carbon and nitrogen pools that are related to patterns of woody plant distribution. However, with regard to spatial patterns, little is known about (i) how they develop; (ii) how they are influenced by grazing; or (iii) the extent to which intraspecific interactions dictate them. We addressed these questi...

      published 2014 in Ecological Applications

      Modeling Vegetation Heights from High Resolution Stereo Aerial Photography: an Application for Broad-Scale Rangeland Monitoring

      by Gillan, Jeffrey K., Karl, Jason W., Duniway, Michael and Elaksher, Ahmed

      Vertical vegetation structure in rangeland ecosystems can be a valuable indicator for assessing rangeland health and monitoring riparian areas, post-fire recovery, available forage for livestock, and wildlife habitat. Federal land management agencies are directed to monitor and manage rangelands at landscapes scales, but traditional field methods for measuring vegetation heights are often t...

      published 2014 in Journal of Environmental Management


      Interpretation of High-Resolution Imagery for Detecting Woodland Cover Composition Change After Fuels Reduction Treatments

      by Karl, Jason W., Gillan, Jeffrey K., Barger, Nichole N., Herrick, Jeffrey E. and Duniway, Michael

      The use of very high resolution (VHR; ground sampling distances &lt; ~5cm) aerial imagery to estimate site vegetation cover and to detect changes from management has been well documented. However, as the purpose of monitoring is to document change over time, the ability to detect changes from imagery at the same or better level of accuracy and precision as those measured in situ must be assesse...

      published 2014 in Ecological Indicators

      Using Spatial Statistics and Point-Pattern Simulations to Assess the Spatial Dependency Between Greater Sage-Grouse and Anthropogenic Features

      by Gillan, Jeffrey K., Strand, Eva K., Karl, Jason W., Reese, Kerry P. and Laninga, Tamara

      The greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse), a candidate species for listing under the Endangered Species Act, has experienced population declines across its range in the sagebrush (Artemisia spp.) steppe ecosystems of western North America. One factor contributing to the loss of habitat is the expanding human population with associated development and infrast...

      published 2013 in Wildlife Society Bulletin