Prdation and Parasitism
Evidence suggests that in some systems, pr dation and parasitism are important drivers of population dynamics Dempster 1983, Hassell 1985 . Competition among insect herbivores, in contrast, is thought to be infrequent Strong et al. 1984, but see Denno et al. 1995, Ohgushi 1997 . Direct effects of climate change on the development rates and activity of insect predators can affect butterfly predation Porter 1983, Courtney 1986 . For example, under local cooling, the food requirements of...
LargeScale Spatial Dynamics of Blister Rust Spread
A deeper exploration into the history of blister rust spread in the United States and Canada since its initial introduction may shed light on the prospects for future whitebark pine infection and mortality within the GYE, and is therefore examined here. Specifically, consideration of the spatial and temporal dimensions of past C. ribi-cola invasion into regions of different vegetation, topographic, and climatic regimes yields insights into the factors that control and limit blister rust spread....
Laura Koteen
The subalpine tree species whitebark pine Pinus albicaulis faces multiple threats to its existence. Predominant among them is the risk posed by the exotic fungus white pine blister rust, Cronartium ribicola . Throughout much of its range Fig. 8.1 , whitebark pine has suffered considerable losses approaching 90 in some locations. Blister rust, mountain pine beetle Dendroctonus ponderosae and successional replacement by subalpine cohorts due to fire exclusion account for the bulk of its...
Literature Cited Apc
Alcamo, J., ed. 1994. IMAGE 2.0 Integrated Modeling of Global Climate Change. Dordrecht Kluwer. Bachelet, D., R. P. Neilson, J. M. Lenihan, and R. J. Drapek. 2001. Climate change effects on vegetation distribution and carbon budget in the United States. Ecosystems 4 164-185. Betts, R. A., P. M. Cox, S. E. Lee, and F. I.Woodward. 1997. Contrasting physiological and structural vegetation feedbacks in climate change. Nature 387 796-799. Bonan, G. B. 1995. Land-atmosphere interactions for climate...
Design of Field and Laboratory Experiments
Using field experiments, I quantified rates of Pisaster predation to test the hypothesis that the strength of the sea star-mussel interaction is reduced during periods of cold-water upwelling. Experiments were conducted at three wave-exposed sites within Neptune State Park. Sites were separated by several hundred meters, and water temperatures varied little generally lt 0.2 C over these distances. At each site, I identified two large rocky reefs mean area SEM 132.5 49.7 m2 that were in close...
Nonparametric Density Estimation Method
Once a set of climatic variables is identified, multivariate nonpara-metric density estimation is applied to estimate probability density functions of each vegetation type. Nonparametric density estimation methods are well understood and have been increasingly used in practice for both univariate and multivariate analysis in such areas as chemical and electrical engineering and medical biostatis-tics. A comprehensive review of different density estimation methods can be found in Silverman 1986...
Index
Abies lasiocarpa. See subalpine fir abrupt climate changes, 38-39. See also extreme weather events Adams, C.T., 304 adaptability factors, 40 Adelie penguins, 155, 171-72 alpine buttercup Ranunculus adoneus , 208-9 alpine chaenactis Chaenactis alpinus , 389 records on, 131 Anderson, B.W., 308 animals. See also invertebrate species mammals specific species current responses of, 22-25 projecting responses by, 19-22 and vegetation, 29-30 Antarctic penguins, 155 Anthocharis caramines British...
Synergisms
The synergistic, or combined, effects of habitat fragmentation and climate change represent one of the most potentially serious global change problems. People destroy or divide natural habitats for farmland, settlements, mines, or other developmental activities. Changes in climate will force individual species of plants and animals to adjust, if they can, as they have in the past. During the Ice Age many species survived by migrating to appropriate habitats. Today such migrations would be much...
Potential Changes in Rocky Intertidal Communities
How might rocky intertidal communities along the central Oregon coast be impacted by changes in the frequency and intensity of upwelling My results suggest that a long-term reduction in cold-water upwelling would cause Pisaster feeding rates to remain consistently high rather than fluctuating. In this case, sustained sea star predation might diminish the vertical extent of the mid-zone mussel beds by shifting the lower limit of these beds to a higher level on the shore. Since mussel beds...
Literature Cited Ebh
Arno, S. F. 1986. Whitebark pine cone crops A diminishing source of wildlife food Western Journal of Applied Forestry 1 92-94. Arno, S. F., and R. J. Hoff. 1989. Silvics of whitebark pine Pinus albi-caulis . Ogden, Utah U.S. Dept. of Agriculture, Forest Service. Arno, S. F., and T. Weaver. 1989. Whitebark pine community types and their patterns on the landscape. Pages 97-105 in W. C. Schmidt and K. J. McDonald, eds., Symposium on Whitebark Pine Ecosystems Ecology and Management of a High...
Examples of Ecological Responses to Climate Changes
Bringing climatic forecasts down to ecological applications at local and regional scales is one way to bridge the scale gap across ecological and climatological studies. Ecologists, however, have also analyzed data and constructed models that apply over large scales, including the size of climatic model grids. A long tradition in ecology has associated the occurrence of vegetation types or the range limits of different plant species with physical factors such as temperature, soil moisture, or...
Blister Rust Life Cycle
The dynamics of the blister rust life cycle reveal the major climatic limitations for the spread of blister rust to whitebark pine. In pines, the blister rust cycle Fig. 8.3 commences in the summer a year or more after pine infection when spermatia, the initial spore stage, form in nectarlike droplets that ooze from the bark. These spores are transmitted by rain or insects that are attracted to the nectarlike exudate and travel from canker to canker. If successfully sperma-tized, the...
Prospects for Future Range Expansions The Red Imported Fire Ant
Abundant evidence of northward temperature limitations on ant distributions led us to begin by examining relationships between January mean minimum temperatures and the occurrence of RIFA. We selected winter temperature minima rather than other temperature-related variables such as growing season length because experimental evidence indicates that absolute temperature minima, not summer or active season minima, drive mortality and brood failure in RIFA. In addition, growing season length...
Tamarix Shrubs in the Wests Riparian Zones
Invasive shrubs of the genus Tamarix18 do not pose the direct threats to human health or agriculture that S. wagneri does. As a result, far less is known about Tamarix and, in general, far less attention has gone to its adverse impacts as it spreads through the western United States. In spite of the serious impacts that it has on water quality and supplies Johns 1990, Wiesenborn 1996 , the frequency and severity of floods Graf 1980, Blackburn et al. 1982 and native wildlife DeLoach 1997 in 23...
Literature Cited Ccv
Alward, R. D., J. K. Detling, and D. G. Milchunas. 1999. Grassland vegetation changes and nocturnal global warming. Science 283 229-231. Andrewartha, H. G., and L. C. Birch. 1954. The Distribution and Abundance of Animals. Chicago University of Chicago Press. Bale, J. S. 1987. Insect cold-hardiness Freezing and supercooling an eco-physiological perspective. Journal of Insect Physiology 33 899-908. Barry, J. P., C. H. Baxter, R. D. Sagarin, and S. E. Gilman. 1995. Climate-related, long-term...
Butterfly Ranges and Climate
Research at many scales clearly shows that climate is important for butterfly abundance and distribution. The basic association between climate and insect distribution and abundance has been studied for at least 70 years e.g., Uvarov 1931, Andrewartha and Birch 1954, Birch 1957, Dennis 1993 .The challenge now is to focus on experiments that will integrate our mechanistic understanding of individual and population processes with distribution limits and change. Large-scale patterns in butterfly...
The Red Imported Fire Ant in the American Southeast
Red imported fire ants Solenopsis wagneri have rapidly invaded the southeastern United States in this century. Since their introduction approximately 80 years ago, they have colonized millions of hectares at densities 4 to 10 times higher than those found in their native habitat of Brazil Porter et al. 1997 . Economic losses due to agricultural damage and direct threats to human health have prompted careful monitoring and study of red imported fire ants RIFA since as early as 1930, providing...
Predicting Changes in Upwelling Intensity
To what extent can we predict how global warming will alter patterns of upwelling along the Pacific coast of North America Coastal upwelling is a complex process affected by atmospheric and oceanic conditions at local, regional, and hemispheric scales Barber 1988 . The intensity of upwelling i.e., the temperature of upwelled waters and its frequency i.e., the duration of events and number of events per season varies naturally from year to year and among different sites along the coast....
Examples of the Historical Method in Action
Recently, a handful of papers have used some form of this historical-descriptive method to demonstrate evidence of species' responses to climate changes that have occurred over the last century. Barry et al. 1995 and Sagarin et al. 1999 documented a general increase in southern invertebrate species and a decrease in northern species between two investigations of a single intertidal site conducted 60 years apart. This faunal change was concomitant with an increase in mean annual shoreline ocean...
Literature Cited Usa
Barry, J. P., C. H. Baxter, R. D. Sagarin, and S. E. Gilman. 1995. Climate-related long-term faunal changes in a California rocky intertidal community. Science 267 672-678. Bazzaz, F. A. 1990. The response of natural ecosystems to the rising global CO2 levels. Annual Review of Ecology and Systematics 21 167-196. Berenbaum, M. R. 1995. Chemistry and oligophagy in the Papilionidae. Pages 27-38 in J. M. Scriber, Y. Tsubaki, and R. C. Lederhouse, eds., Swallowtail Butterflies Their Ecology and...
Verifying Climate Forecasts
The most perplexing question about climate models is whether they can be trusted as a reliable basis for altering social policies, such as those governing CO2 emissions or the shape and location of wildlife reserves. Even though these models are fraught with uncertainties, several methods are available for verification tests. Although no method is sufficient by itself, several methods together can provide significant, albeit circumstantial, evidence of a forecast's credibility. The first...
Does Snowmelt Date Affect the Flowering Time of Delphinium Nuttallianum
Price and Waser's 1998 observations on the global warming experiment at the RMBL Harte et al. 1995, Harte and Shaw 1995 suggested that if winter precipitation patterns in the form of snow don't change, flowering date will shift with global warming by shifting the snowmelt date. If precipitation changes, these predictions could fail. Current models of climate change, however, have no clear predictions about whether precipitation will increase or decrease at a regional level. The most likely...
Atalopedes campestris A Case Study
Atalopedes campestris, the sachem skipper, is a common, generalist butterfly in the family Hesperiidae subfamily Hesperiinae grassfeeding skippers Scott 1986 . It is the only member of its genus that extends beyond the neotropics. A. campestris ranges from south of the equator into the United States Burns 1989 . In the central and eastern United States it frequently disperses northward in mid to late summer, but it dies out over winter and contracts to a permanent range in the southern states...
Qualitative Responses to Climate Change
In the absence of evolutionary change, populations have four possible responses to climate change expand, decline, move, or go extinct see Cohn 1989, Peters and Lovejoy 1992, Gates 1993, Kareiva et al. 1993 . If climate change improves the quality or total area of suitable habitat e.g., removing abiotic or biotic barriers to occupancy , populations can expand or increase in density and new populations can be established. Alternatively, if climate change impacts a species negatively, populations...