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Roy Darville

Publications and source records attributed to Roy Darville.

2 recordsLinked to original sources

Effects of herbivory and flooding on reforestation of baldcypress ( Taxodium distichum [L.]) saplings planted in Caddo Lake, Texas

The effects of herbivory and flooding were examined on survival and growth of planted baldcypress ( Taxodium distichum (L.) Rich.) saplings at three sites in Caddo Lake, TX, over a 4-yr period. There were two flood regimes (shallow periodic and deep continuous), where half of the saplings in each flood regime were protected by tree shelters to prevent herbivory. By the end of the first year, over 80% of saplings survived with half of saplings classified as healthy. By the end of the fourth year, only half of the saplings were alive and one-third were healthy. At all three sites, the combination of no protection and continuous flooding resulted in a significant number of missing saplings. Likewise, most unprotected saplings in periodic flooding were missing by the end of the study. Saplings clipped by herbivores showed about 50% chance of recovery, but many of the sprouts were of poor quality. Protected saplings in tree shelters achieved significantly greater survival and height growth.

Louisiana, Texas

A comparison of litter production in young and old baldcypress (Taxodium distichum L.) stands at Caddo Lake, Texas

Aboveground primary productivity for cypress forests was assessed from measurements of litter production in two age groups and in two hydrological regimes (standing water and free-flowing). Caddo Lake, located in northeast Texas on the Texas-Louisiana border, offered a unique study site since it is dominated by extensive stands composed entirely of Taxodium distichum (L.) Rich, (baldcypress) in different age groups. Young stands (approximately 100 years old) are found along the shoreline and on shallow flooded islands. Old stands (-150 to 300 years old) are found in deeper water where they were continuously flooded. Litter production over three years from October 1998 to September 2001 was measured. Litter consisting of leaves, twigs, bark, reproductive parts, and Tillandsia usneoides (L.) L. (Spanish moss) was collected monthly using 0.5 m 2 floating traps. Tree diameters were measured within 200 m 2 circular plots in each stand. The young stands supported densities greater than 2,000 stems/ha and a mean stand basal area of 72.3 m 2 /ha, whereas old stands supported lower densities of about 500 stems/ha but with a similar mean stand basal area of 73.3 m 2 /ha. There was a significant difference between old and young stands for overall yearly litter production, averaging about 670 g/m 2 /yr in the young stands and 460 g/m 2 /yr in the old stands. Leaves and twigs were significantly greater in the young stands, while reproductive parts were higher in old stands. Litter collections between years or hydrological regimes were not significantly different.

Texas