THE ABILITY OF POLLEN FROM SMALL LAKES AND PONDS TO SENSE FINE-SCALE VEGETATION PATTERNS IN THE CENTRAL ROCKY-MOUNTAINS, USA

Pollen ratios and linear discriminant analysis were used to detect fin e-scale vegetation patterns in the subalpine zone of the central Rocky Mountains, USA. The vegetation of this zone is a mosaic of conifer fo rests and treeless parks dominated by sagebrush (Artemisia spp.) and g rasses. Previous work with pollen surface samples in the region has co rrelated modern pollen rain to broad-scale vegetation zones (e.g. step pe, montane forest, subalpine forest, and tundra), but little effort h as been made to detect fine-scale (hundreds to thousands of meters) pa tterns within these vegetation zones. Previous theoretical studies sug gest that vegetation patterns on the scale of hundreds of meters shoul d be recorded in the pollen deposited in small ponds. Pollen surface s amples were collected from small ponds and lakes (30-350 m diameter) f rom subalpine vegetation in Colorado and Wyoming. An additional set of samples was collected from small ponds in a park and the surrounding forest in the Wind River Range of northwest Wyoming. Pollen percentage s were not dramatically different in park and forest assemblages, but the ratio of conifer to herb and Artemisia pollen (C:H) and the linear discriminant score were successful in separating park and forest poll en assemblages.