New Advances in Fern Ecology
Sharpe, Joanne M. .
Long-term studies of ferns in Puerto Rico.
THE emphasis on long-term studies at the NSF-funded Luquillo Long Term Ecological Site in Puerto Rico has permitted continuous observation of marked fern individuals in the rainforest there since 1991. The objective of the study is to identify patterns of temporal variation in a number of growth-related characteristics of fern sporophytes in a hurricane-prone tropical forest. Tropical ferns produce leaves continuously rather than in the annual flushes generally seen in temperate zone ferns. Thus the type and morphology of each leaf reflects the plant's opportunity to adjust its response to a changing habitat. Temporal variation can be assessed at several scales including daily increments in leaf growth, seasonal changes in sporophyll production, and year to year changes in leaf lengths. Less frequent, often cyclic events such as hurricanes, droughts and floods also have an impact on fern growth. In this study, changes in morphological characteristics such as number of leaves in the crown, length of leaves, and counts of leaflet pairs are compared for several understory species. Temporal patterns of leaf life spans, leaf production rates, and sporophyll production are also analyzed. Different species have different responses to changes in their environment, as do individuals within a species. By determining which measures are most sensitive to change over time, ecologists can use standardized observations to assess the role of ferns in an ecosystem. Biomass estimates combined with a knowledge of leaf turnover rates in ferns adds an element to general ecosystem studies that is often ignored. Long-term observations of natural phenomena also identify patterns that can lead to short-term experiments to identify underlying causes for the temporal variation observed.
Log in to add this item to your schedule
1 - Sharplex Services, P.O. Box 499, Edgecomb, Maine, 04556, USA
leaf life span
Presentation Type: Symposium or Colloquium Presentation
Date: Monday, July 31st, 2006
Time: 10:00 AM