Ahjond S. Garmestani

Firm size diversity, functional richness, and resilience

This paper applies recent advances in ecology to our understanding of firm development, sustainability, and economic development. The ecological literature indicates that the greater the functional richness of species in a system, the greater its resilience - that is, its ability to persist in the face of substantial changes in the environment. This paper focuses on the effects of functional richness across firm size on the ability of industries to survive in the face of economic change. Our results indicate that industries with a richness of industrial functions are more resilient to employment volatility.

Nest-site selection by the loggerhead sea turtle in Florida's Ten Thousand Islands

Loggerhead sea turtles (Caretta caretta) nest in numerous substrate and beach types within the Ten Thousand Islands (TTI) of southwest Florida. Nest-site selection was analyzed on 12 islands within this archipelago. Physical characteristics of beaches were recorded to identify the relatedness of these var- iables and to determine their importance for nest-site selection in C. caretta. These characteristics included ordinal aspect, beach length, height of canopy, beach width, overall slope (beach slope and slope of offshore approach), and sand samples analyzed for pH, water content, organic content, shelliness (% of calcium car- bonate content), and particle size (8 size classes). All physical variables, as well as nesting densities and locations, were included in a tree regression model to examine nest-site selection. In the TTI, loggerheads use wide beaches (>8.5 m) that inherently have less slope and, secondarily, wide beaches that have less shells (low amounts of calcium carbonate; >8.5 m) in the nesting substrate. In addition, C. caretta nest sites were located within or in close proximity to the supra-littoral vegetation zone of beaches in the TTI.

Raccoon Removal Reduces Sea Turtle Nest Depredation in the Ten Thousand Islands of Florida

Abstract Predation by raccoons, Procyon lotor marinus (L.), is the primary cause of sea turtle nest loss in the Ten Thousand Islands archipelago. Four islands within Ten Thousand Islands National Wildlife Refuge were surveyed for sea turtle nesting activity from 1991–95. Raccoons depredated 76–100% of nests on Panther Key from 1991–94, until 14 raccoons were removed in 1995 resulting in 0% depredation and 2 more were removed in 1996 resulting in 0% depredation. Raccoon removal may be an effective management option for increasing sea turtle nest survival on barrier islands.

When landscaping goes bad: The incipient invasion of Mahonia bealei in the southeastern United States

Woodlots are forest islands embedded within an urban matrix, and often represent the only natural areas remaining in suburban areas. Woodlots represent critical conservation areas for native plants, and are important habitat for wildlife in urban areas. Invasion by non-indigenous (NIS) plants can alter ecological structure and function, and may be especially severe in remnant forests where NIS propagule pressure is high. Woody shrubs in the Family Berberidaceae have been well documented as invaders of the forest–urban matrix in North America. Mahonia bealei (Berberidaceae) is a clonal shrub native to China, and is a popular ornamental in the Southeastern United States. Mahoni bealei is listed as “present” on some local and state floras, but almost nothing is known regarding its invasion potential in the United States. We sampled 15 woodlots in Clemson, South Carolina, to assess the invasion of M. bealei and other woody non-indigenous species (NIS). M. bealei invaded 87% of the woodlots surveyed and species richness of NIS on these woodlots varied from 5 to 14. Stepwise-multiple regression indicated that less canopy cover and older M. bealei predicted greater abundance of M. bealei , and that not all subdivisions were equally invaded (P < 0.0001; r2 = 0.88). The impact of M. bealei on native flora and fauna may be considerable, and it is likely to continue to spread in the Southeastern United States. M. bealei should be recognized as an aggressive invader in the Southeastern United States, with the potential for negative impacts on native flora and fauna.