PARENT SESSION
Oral Session #20: Invasions: Effects of invaders -- terrestrial systems. Presiding: R. Callaway.
Tuesday, August 7, 2001. 8:00 AM to 12:00 PM. Madison Ballroom C.
Community and ecosystem impacts of the invasive tree Acer platanoides in natural forest.
Fang, Wei 1, 1
ABSTRACT- I evaluated the community and ecosystem impacts of Norway maple (Acer platanoides; AP) by carrying out a factorial field manipulative experiment and measuring ecosystem properties in a natural mesic forest. Seedlings of 4 native species and 4 exotic species were transplanted under mature AP and its native congenor Acer rubrum (AR). The effects of above and below-ground competition and litter effects of adult AP and AR were tested by removing half canopies, trenching, and removing litter. Understory light availability, soil moisture and soil N-mineralization were measured in the experimental plots. Results indicated that seedlings survived and grew better under AR than under AP. Light under AR was the most limiting factor for understory seedling survival and growth (P<0.001). Root competition for water and N by AR adults also contributed sigificantly to the lack of understory under AR (P<0.001). Litter of AR was beneficial for seedlings (P<0.001), with no detectable negative effects. Different understory species responded to experimental treatments differentially, which indicated that AR invasion may potentially alter the community composition of undisturbed natural woodland.
KEY WORDS: Acer platanoides, impact of invasion, tree invader, community composition and diversity