Posted by: Dan | November 27, 2006

Migratory Species: Articles on Climate Change and Fire Suppression

Continuing with the theme of “all things migratory” and biophilia, there are two articles in the last week+ that I’d like to spotlight:

1. Migratory species threatened by global warming:

Urgent action is need to prevent extinction of migratory species due to global warming says a new report from the United Nations Environment Programme (UNEP).

Citing a number of examples, the report says that climate change is having an increasing impact on migratory species by diminishing habitat, forcing changes in migration routes, disrupting food sources, affecting nesting and breeding habits, and increasing susceptibility to disease.

“Migratory species are in many ways more vulnerable as they use multiple habitats and sites and a wide suite of resources throughout their migratory cycle. So we need to bolster rather than clear habitats, reduce pollution to the land, freshwater and the marine environment, more sustainably manage water supplies for people and wildlife and enact other measures to assist animals and plants to cope and to adapt in a climatically changed world,” said Achim Steiner, UN Under-Secretary General and UNEP Executive Director. “Unchecked, climate change will pile on more pressure making it increasingly difficult for the world to… reduce the rate of loss of biodiversity by 2010.”

The report says that preventing climate change is also an economic priority.

2. Food For Flight: Monarch Butterfly Migration And Forest Restoration:

USDA Forest Service (FS) research in the Ouachita Mountains of Arkansas suggests that decades of fire suppression have reduced the area’s food supply for migrating monarch butterflies—and that restoration efforts that include prescribed burning can reverse this trend. Craig Rudolph and Ron Thill, research ecologists with the FS Southern Research Station (SRS), along with SRS ecologists Charles Ely, Richard Schaefer and J. Howard Williamson, report their findings in the latest issue of the Journal of the Lepidopterists’ Society.

Every fall, masses of monarch butterflies migrate across eastern North America to remote sites in central Mexico—a long flight fuelled only by nectar from flowers still blooming on the way. In recent years, there have been concerns about the continued health of monarch populations, and of the migration itself, as land use change has altered both breeding habitat and migratory pathways.

Studies have focused on food availability for larvae, pesticides, and loss of overwintering sites in Mexico as possible threats. Less attention has been paid to how landscape-level changes affect the availability of the butterfly’s preferred nectar sources along their migratory routes. In September and October, large numbers of monarchs pass through the Ouachita Mountains, a largely forested area in Arkansas and Oklahoma where fire suppression, logging, and pine production practices have altered forest structure, leading to a drastic reduction in the quality and abundance of the flowering plants the butterflies rely on for nectar.


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