1fs. Plant Migrations and Global ChangeAs global temperatures have
warmed and cooled, plant communities have responded by migrating
poleward during periods of glacial retreat and equatorward as glaciers
advanced. For example, large tracts of species such as spruce that once
inhabited much of what is now the northern and northeastern United
States have shifted northward into Canadian regions formerly covered by
glacial ice.The rate at which plant communities can migrate in response
to changing climates is important to their survival, If plant
communities are too slow to adapt to changing conditions, the vegetation
type faces possible extinction. Because of the possibility of future
rapid increases in global temperatures, scientists are concerned about
the potential for major changes in Earth’s plant communities. It is
clear that some species in a plant community might be better able to
expand their boundaries than others. Such changes in the rate of
migration for individual species would lead to a change in the plant
community, in which the overall composition of the plants in the new
environment is different from what it previously was. For example, trees
have longer life spans and reproductive cycles than brushy plants, and
therefore take longer to adapt to changing environmental
conditions.Moreover, the expansion of suburbs and agriculture into
previously undisturbed areas has caused some plant communities to become
fragmented. In other words, instead of having extensive areas of a
particular plant community, those vegetation associations now occur in
isolated patches. The fragmentation of these communities hinders their
ability to migrate in response to climate change and could make some
future migrations impossible.An interesting example of rapid vegetation
change due to increasing temperatures has been observed in the
grasslands of northeastern Colorado (Figure 16-3-1). A trend toward
increasing nighttime temperatures has caused the average date of the
last killing frost to occur earlier in the spring. This has put the
normally dominant grass species—the blue grama, which historically has
accounted for 90 percent of the ground cover—at a competitive
disadvantage compared to various weeds. The weeds that are taking over
the grasslands landscape are far more susceptible to drought. This is
highly significant to ranchers who rely on the grass cover to supply
most of their livestock’s food needs.FIGURE 16-3-1 Prairie at Pawnee
National Grassland, northeastern Colorado....How does climate change
pose challenges to plant communities? Get solution
2fs. Plant Migrations and Global ChangeAs global temperatures have warmed and cooled, plant communities have responded by migrating poleward during periods of glacial retreat and equatorward as glaciers advanced. For example, large tracts of species such as spruce that once inhabited much of what is now the northern and northeastern United States have shifted northward into Canadian regions formerly covered by glacial ice.The rate at which plant communities can migrate in response to changing climates is important to their survival, If plant communities are too slow to adapt to changing conditions, the vegetation type faces possible extinction. Because of the possibility of future rapid increases in global temperatures, scientists are concerned about the potential for major changes in Earth’s plant communities. It is clear that some species in a plant community might be better able to expand their boundaries than others. Such changes in the rate of migration for individual species would lead to a change in the plant community, in which the overall composition of the plants in the new environment is different from what it previously was. For example, trees have longer life spans and reproductive cycles than brushy plants, and therefore take longer to adapt to changing environmental conditions.Moreover, the expansion of suburbs and agriculture into previously undisturbed areas has caused some plant communities to become fragmented. In other words, instead of having extensive areas of a particular plant community, those vegetation associations now occur in isolated patches. The fragmentation of these communities hinders their ability to migrate in response to climate change and could make some future migrations impossible.An interesting example of rapid vegetation change due to increasing temperatures has been observed in the grasslands of northeastern Colorado (Figure 16-3-1). A trend toward increasing nighttime temperatures has caused the average date of the last killing frost to occur earlier in the spring. This has put the normally dominant grass species—the blue grama, which historically has accounted for 90 percent of the ground cover—at a competitive disadvantage compared to various weeds. The weeds that are taking over the grasslands landscape are far more susceptible to drought. This is highly significant to ranchers who rely on the grass cover to supply most of their livestock’s food needs.FIGURE 16-3-1 Prairie at Pawnee National Grassland, northeastern Colorado....Describe one way in which human activities make it difficult for plant species to migrate in response to climate change. Get solution
2fs. Plant Migrations and Global ChangeAs global temperatures have warmed and cooled, plant communities have responded by migrating poleward during periods of glacial retreat and equatorward as glaciers advanced. For example, large tracts of species such as spruce that once inhabited much of what is now the northern and northeastern United States have shifted northward into Canadian regions formerly covered by glacial ice.The rate at which plant communities can migrate in response to changing climates is important to their survival, If plant communities are too slow to adapt to changing conditions, the vegetation type faces possible extinction. Because of the possibility of future rapid increases in global temperatures, scientists are concerned about the potential for major changes in Earth’s plant communities. It is clear that some species in a plant community might be better able to expand their boundaries than others. Such changes in the rate of migration for individual species would lead to a change in the plant community, in which the overall composition of the plants in the new environment is different from what it previously was. For example, trees have longer life spans and reproductive cycles than brushy plants, and therefore take longer to adapt to changing environmental conditions.Moreover, the expansion of suburbs and agriculture into previously undisturbed areas has caused some plant communities to become fragmented. In other words, instead of having extensive areas of a particular plant community, those vegetation associations now occur in isolated patches. The fragmentation of these communities hinders their ability to migrate in response to climate change and could make some future migrations impossible.An interesting example of rapid vegetation change due to increasing temperatures has been observed in the grasslands of northeastern Colorado (Figure 16-3-1). A trend toward increasing nighttime temperatures has caused the average date of the last killing frost to occur earlier in the spring. This has put the normally dominant grass species—the blue grama, which historically has accounted for 90 percent of the ground cover—at a competitive disadvantage compared to various weeds. The weeds that are taking over the grasslands landscape are far more susceptible to drought. This is highly significant to ranchers who rely on the grass cover to supply most of their livestock’s food needs.FIGURE 16-3-1 Prairie at Pawnee National Grassland, northeastern Colorado....Describe one way in which human activities make it difficult for plant species to migrate in response to climate change. Get solution
