PARENT SESSION
Oral Session #94: Nutrient Cycling.
Presiding: R. Yanai
Thursday, August 8. 1:00 PM to 3:45 PM. Grand Ballroom East, Radisson.
Pocket gophers accelerate litter decomposition and nutrient turnover in a longleaf pine ecosystem.
CLARK, KENNETH*,1, BRANCH, LYN1, FARRINGTON, JENNIFER1, 1 University of Florida, Gainesville, Florida
ABSTRACT- Soil disturbance by burrowing animals results in burial of the litter layer in many ecosystems. We examined how burial of litter by pocket gophers (Geomys pinetis) affects decomposition and nutrient dynamics of longleaf pine (Pinus palustris) and turkey oak (Quercus laevis) litter using litterbags on the forest floor and buried beneath fresh mounds over 4 years in north Florida. Mass loss from both types of litter was greater beneath mounds than in the litter layer for all collection dates, and turkey oak foliage decomposed more rapidly than longleaf pine needles in both locations, reflecting higher litter quality. Mass loss from longleaf pine litter beneath mounds and on the forest floor was 39.4% vs. 23.4% after one year, and 56.4% vs. 37.5% after two years, while mass loss from turkey oak litter was 55.0% vs. 25.7% after one year, and 66.9% vs. 43.2% after two years. Concurrent mound censuses and litterfall collections indicated that ca. 5% of annual litterfall (763 kg ha-1 longleaf pine needles and 714 kg ha-1 turkey oak foliage) was buried by mounds annually. Pocket gophers accelerate decomposition and N and P release from litter in this ecosystem where productivity is likely to be nutrient limited.
KEY WORDS: pocket gophers, decomposition, nutrient dynamics, longleaf pine ecosystem