PARENT SESSION
Oral Session #62: Vegetation change: Succession, recovery, facilitation. Presiding: S. Franklin.
Thursday, August 9, 2001. 8:00 AM to 12:00 PM. Hall of Ideas G.

Controls on early rates of succession in a Virginia Piedmont old-field.

Riedel, Sebastian¹, Epstein, Howard¹, ¹

ABSTRACT- There are many factors that influence plant community production and structure during succession on temperate old-fields. To investigate the effects of proximity to forest edge and method of abandonment on ecosystem properties and community structure during succession, field measurements of leaf area index (LAI), specific leaf area (SLA), and species composition, as well as soil samples, were collected along four transects within a 14 year old temperate successional field over the 2000 growing season. Values of LAI and SLA were used to estimate levels of foliar production, while relative frequencies of early versus late successional species were used to provide information regarding states of succession. Results show a significant positive relationship between proximity to forest edge and LAI (r = 0.62, p < 0.001). Additionally, the presence of several key plant species exhibited a strong control on the variability of LAI. The absolute frequency of Celastrus orbiculatus (Japanese bittersweet) had a significant positive relationship with LAI (r = 0.84, p < 0.001). In general, frequencies of late successional species increased with proximity to forest edge and in sites plowed at time of abandonment, suggesting greater rates of succession at these locations. However, soil carbon levels do not show a significant increase at sites in later successional states, suggesting that the recovery period for soil carbon in these systems is greater than 14 years.

KEY WORDS: succession, leaf area index (LAI), old-field, Virginia