Infrared photo of trees in landscape
Yellowstone Ecoregion Mountain Pine Beetle project
A range of wood-boring beetles (including the mountain pine beetle) have affected broad
areas of the Rocky Mountains over the past two decades. These infestations are unprecedented in historical times, and correspond to a period of warming climate that has decreased winter mortality of beetles and led to latitudinal and longitudinal range expansion. Our objective was to develop an automated and repeatable method to map the timing, extent and severity of beetle-caused mortality in the Greater Yellowstone Ecosystem. We calibrated a long Landsat image time series against field measurements of mortality made between 2006 and 2012. We have been able to map the year-to-year progression of beetle-caused forest percent mortality through the ecoregion. This method provides a tool for estimating forest mortality in other locations using similar methods.
Bark beetle exiting tree
- Ken Raffa and Erinn Powell, Department of Entomology, UW-Madison
- Monica Turner, Department of Zoology, UW-Madison
Nutrients are exchanged between ecosystems in many ways.
The direction and magnitude of fluxes across the landscape can dramatically influence ecosystem processes. In Lake Myvatn in northern Iceland, an abundance of midges (in Icelandic, ‘my’ is midge, and ‘vatn’ is lake) emerge from the lake on a boom-and-bust cycle approximately every 7 years and create a visible ‘ring’ of enhanced vegetation growth around the the lake due to a nutrient subsidy from midges deposited on land.
From 2008 to 2011 we measured midge emergence from the lake and their subsequent deposition on land. We developed a model to map midge deposition as a function of distance-from-lake and wind direction. As well, we employed ASTER, Landsat, and Hyperion imagery to map foliar nitrogen, species composition, and aboveground biomass around the lake. The results show the strong influence of midge movement from lake to land on terrestrial ecosystem dynamics, the effects of which are clearly visible in spaceborne satellite imagery.
Contacts: Clayton Kingdon, Phil Townsend
Wildlife management agencies are tasked with balancing problems of wildlife overabundance (e.g. damage to agriculture, nuisance) with problems of scarcity (e.g. risk of extinction, loss of ecosystem services) and citizens’ desires for hunting opportunities, wildlife viewing, and other wildlife-associated values. Population management decisions generally involve three steps: 1) determination of a population goal for the species based on scientific and public input, 2) estimation of population distribution, size and projected growth, and 3) establishment of population manipulation (most frequently a hunting quota or conservation target) designed to align population sizes with management goals.
Wildlife distributions, in turn, are constrained by habitat preferences that vary strongly both within (i.e. phenology) and across years (i.e. land cover change). Vegetation type, proportion, and spatial pattern provide measures of the availability of food, water, cover and protection for both herbivores and their predators. Seasonal dynamics of vegetation cover and forage availability may also influence wildlife movements and distributions. Timing of greening for both natural and agricultural vegetation correlates with the availability of cover and food for a number of wildlife species, especially those that inhabit human-modified landscapes.
This study will utilize citizen-classified [link to snapshot wisconsin website, modeled on http://www.snapshotserengeti.org/] trailcam photographs deployed by the Wisconsin DNR in conjunction with Landsat-derived measures of habitat type distributions, as well as MODIS-derived temporally-dense measurements of greenness, environmental productivity and phenology to assess:
- Spatio-temporal occupancy patterns and detection rates of wildlife
- Trends in populations of target species
- Influence of habitat structure, composition and seasonality on vital demographic rates of target wildlife populations.
Ben Zuckerberg, Tim Van Deelen, Karl Martin
We can observe and describe forest disturbances in a number of ways using satellite imagery, airborne observations, and field measurements. Our work in Upper Midwest and Great Lakes forests considers numerous disturbance types: severe storm winds, insect defoliation, fire, and various partial and clear-cut harvest treatments. We’ve collected a number of field measurement datasets in Minnesota and Wisconsin, especially in areas of spruce budworm outbreak and the Pagami Creek fire. Hyperspectral images from NASA AVIRIS overflights, and multispectral images from Landsat and MODIS, are employed extensively in this work. To identify disturbed areas we reduce the information from multiple spectral bands to calculate vegetation index values for each pixel. Using multiple dates of imagery, these values are compared with nearby undisturbed forest pixels to detect changes over time and subsequently identify the extent and severity of the disturbance.