Study plots were designated around Lake Duparquet in Quebec to witness the effects of flooding on black ash populations surrounding the lake. Both natural and gradual fluctuations in spring flood levels have enabled black ash populations to adapt to their changing environment. Researchers observed that population stability was due to the strategically different reproduction methods between trees located within the floodplain and trees located in higher elevations. Near the lake, trees relied mainly on vegetative sprouting while less exposed trees away from the lake relied mainly on seed dispersion and germination. Researchers conclude that it is this unique adaptation of black ash to rely on two types of reproduction that characterizes its resilience to flooding disturbance. This reliance may be the trees' natural insurance against the increasing levels of stress influenced by global climate change. But researchers warn that this insurance may only be effective in large stands; smaller groups of trees may not contain the same characteristics and may be more vulnerable to floods.
Exotic Plant Species Invade Hot Spots of Native Plant Diversity
Researchers in Colorado have conducted long term studies on the patterns of
exotic plant invasions that have recently challenged some of ecology's existing
paradigms. It has been widely hypothesized that diversity begets stability.
Areas of low diversity were thought to be less complex systems, while highly
diverse areas were considered more complex and thus more efficient in usi
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Contact: Alison Gillespie, Public Affairs Officer
alison@esa.org
202-416-6181
Ecological Society of America
18-Feb-1999