Microclimatic differences between young longleaf-pine silvopasture and open-pasture

摘要

Information is needed relative to changes that occur in microclimatic conditions in the early stages of open-pasture to pine silvopasture conversion in the Southeastern USA. This research tested the hypothesis that microclimatic conditions would vary between young-pine silvopasture and open-pasture. The research was conducted in a longleaf-pine (Pinus palustris Mill.)-bahiagrass (Paspalum notatum Flugge) silvopasture and adjacent open bahiagrass pasture at Americus, Georgia. Longleaf-pine was planted in the bahiagrass pasture in December 2000; the trees were not pruned or thinned until the study was completed. Microclimatic parameters (air temperature, soil temperature at 5 and 10 cm, wind speed, gust speed, wind direction, humidity, dew point, rainfall, soil-moisture content, total solar radiation, and photosynthetically active radiation) were collected from November 2005 to October 2008 using HOBOA (c) weather stations located in each pasture type. Data were analyzed to determine overall, as well as seasonal, monthly, and diurnal differences between pasture types. Evapotranspiration was calculated from air temperature, wind speed, relative humidity, and total solar radiation. With the exception of rainfall, overall average values for all microclimatic parameters were different between pasture types. Silvopasture had higher overall average values for air temperature, soil temperature at both depths, and soil water content, but lower values for all remaining microclimatic parameters. Seasonal, monthly, and diurnal differences between pasture types were also detected for several parameters. The results suggested that water loss can be significantly reduced in the early stages of open-pasture to longleaf-pine silvopasture conversion in the Southeastern USA.