The Use of Remote Sensing Technology Combat Mountain Pine Beetle Infestations
The Mountain Pine Beetle
Figure 1: The mountain pine beetle, Dendroctonus ponderosae Hopkins
The Mountain Pine Beetle (Dendroctonues ponderosae Hopkins) is viewed as an insect that can pack a deadly punch to the mature lodgepole pine trees which inhabit a great deal of land in North America (Fig. 1.). The North American native’s habitat can vary in location as they inhabit from British Columbia to even Mexico but they also can inhabit diverse ranges of elevation. In some cases the (MPB) has been found near sea level in British Columbia but also found at 11,000 feet in Southern California
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The Mountain Pine Beetle (Dendroctonues ponderosae Hopkins) is viewed as an insect that can pack a deadly punch to the mature lodgepole pine trees which inhabit a great deal of land in North America (Fig. 1.). The North American native’s habitat can vary in location as they inhabit from British Columbia to even Mexico but they also can inhabit diverse ranges of elevation. In some cases the (MPB) has been found near sea level in British Columbia but also found at 11,000 feet in Southern California. (Fig. 2.)
The Mountain Pine beetle does not just have a preference for mature lodgepole pine trees as they tend to dwell in three other host species. The ponderosa, sugar and white pines tend to be common species infected. Limber, Coulter, foxtail, whitebark, pinyon, and bristlecone pines are also infested and killed by the beetle while Douglas-fir, true firs, spruce, larch, and incense cedar are occasionally attacked
The Mountain Pine Beetle begins attacking most pine species around the 15 feet mark and below and can kill these trees by just a single generation of beetles. Due to the infectious aspect of the beetles, tree mortality has been affected which, in turn, has been viewed as epidemics. These epidemics have been the cause of entire commercial pine forests being depleted and even in some extremes have taken valuable forests and created voids of grass and shrubbery.
Figure 2:Mountain Pine Beetle Habitat
The Life Cycle
The beetle develops in four stages: egg, larva, pupa, and adult. The beetle spends nearly the entirety of its life within a trees bark except for a handful of days in the summer in which adult beetles exit the tree to fly to a new tree. The life cycle of the beetle is one year, which puts the rate of destruction in perspective as earlier it was stated that one generation of beetles can kill a mature tree. Once under the bark of a tree, the female beetles create egg galleries which are packed with boring dust and can range from 4 to 48 inches long (Fig. 3.). The tiny, almost pearl like eggs the female lays are usually produced in the summer and early fall and the eggs usually hatch within 10-14 days.
Figure 3: Egg Galleries
Figure 4: Exit Hole
Occasionally, females that survived the winter can also lay eggs in late spring by females that survived the winter as it is common for surviving females to reemerge and reattack trees or simply extend their egg galleries.
The larvae remain in the same stage for nearly 10 months, usually from August to the following June, the legless larvae are white with brown heads feed on phloem until mature where then they excavate oval cells in which they turn into pupae. By July, the pupae usually have been transformed into adults.
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Adults will feed on the bark of the tree from within as they are making the trek for an exit. The beetles will gather and either take turns or work together to tunnel out of the tree and once complete, several adults will emerge from each hole created and therefore within 1-2 days will be attacking another tree.
Remote Sensing and the Mountain Pine Beetle
While Mountain Pine Beetles are merely little insects it is fascinating at the damage in which they can cause in one winter. The issue is that the infestations across North America have continually seemed to increase. More than likely this is due to climate change, as the climate slowly warms the less likely we will see harsh winters which is one of nature’s regulatory features over the beetle.
In British Columbia, this particular insect has killed nearly 40 million acres of trees throughout the region in contrast to the 235 million acres total in such region. This is not only a negative in terms of our environment but also monetarily. Since 2001, British Columbia alone has spent more than $917 million while also committing to $1.1 billion to fight the beetle.
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Across North America the Mountain Pine Beetle has wreaked destruction for many years as its influence steepens the slope of mortality rates in the trees it lives. Remote sensing allows for the use of accurate of its application to better identify, monitor and predict mountain pine beetle infestations.
Identifying infestations is crucial in the management of such forests as the beetles is an imminent threat which needs to be considered with much respect for its potential to disrupt local ecologies.
Figure 5: Infected Trees Cleared
Figure 4: Aerial Photo of MPB Infestation Stages
MPB Attack seen by RGB band combination used was Landsat TM bands 5, 4, and 3 with a 2 SD stretch. Dark green areas represent healthy forest, reddish areas MPB, and harvested areas light green or magenta.
Remote sensing allows for the identification of infected trees, this important step aides in a multifaceted approach in which foresters are beginning to utilize more and more. Aerial photography is one way in which allows for the viewing of infected trees (Fig. 4.). The mountain pine beetle is not necessarily very good at hiding itself within the trees as throughout the progression of infestation in a particular host, the foliage of the tree will differ from its normal trajectory. This means that we can relatively identify infestations at different stages by the naked eye due to the change in foliage brought on by the slowing and ceasing of chlorophyll production.
Temporal applications are also utilized as they can give the user an ability to dig deeper than the human eye. Since the insects directly impact the trees life, in the form of death it is feasible to subject the infestations to further imaging (Fig. 5.). The imaging produced is crucial in the process of determining the degree of infestation in a specified region.
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With the ability to not only identify these infestations but to also allow for the tracking of its progression through life cycles. With trouble stopping the mountain pine beetle on its path of destruction, we must prepare. It is not as simple as just the loss of trees as it has an entire ecological affect but also human affect. In regions where the beetle is common the dead trees pose a threat as it still contains insects. While still a threat in a lifeless tree, proper steps must be taken which is heavily reliant on remote sensing data as these trees need to be identified so they can be cut and rotated correctly in the sun for the beetles to be exterminated.
Classified Mountain Pine Beetle Activity
Additional Resources
References
Chapman, T.B., Veblen, T.T., Schoennagel, T., 2012. Spatiotemporal patterns of mountain pine beetle activity in the southern Rocky Mountains. Ecology 93, 2175–2185. http://dx.doi.org/10.1890/11-1055.1
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Walter, J.A., Platt, R.V., 2013. Multi-temporal analysis reveals that predictors of mountain pine beetle infestation change during outbreak cycles. For. Ecol. Manage. 302, 308–318. http://dx.doi.org/10.1016/j.foreco.2013.03.038.
Wulder, M.A., Ortlepp, S.M., White, J.C., Nelson, T., and Coops, N. C. 2010. A provincial and regional assessment of the mountain pine beetle epidemic in British Columbia: 1999–2008. J. Environ. Inform. 15(1): 1–13. doi:10.3808/jei.201000161.
Mountain Pine Beetle – Ontario's Invading Species Awareness Program. (n.d.). Retrieved from http://www.invadingspecies.com/mountain-pine-beetle/
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Nelson, K.N. 2009. The effect of mountain pine beetle caused mortality on subalpine forest stand and landscape structure in Rocky Mountain National Park, CO. M.Sc. thesis, Department of Forest, Rangeland, and Watershed Stewardship, Colorado State University, Fort Collins, Colorado.
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Price, J.I., McCollum, D.W., and R.P. Berrens. 2010. Insect infestation and residential property values: a hedonic analysis of the mountain pine beetle epidemic. Forest Policy and Economics. DOI: 10.1016/j.forpol.2010.05.004.
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Vanonckelen, S., Lhermitte, S., Van Rompaey, A., 2013. The effect of atmospheric and topographic correction methods on land cover classification accuracy. Int. J. Appl. Earth Obs. Geoinf. 24, 9–21. http://dx.doi.org/10.1016/j.jag.2013.02.003