A statistical analysis of characteristics of Carex retroflexa Willd. and Carex texensis (Torr.) L. H. Bailey is provided. This analysis confirms the distinctiveness of these two species, which some authors have considered as a single taxon in the past. Analysis reveals Carex texensis perigynia average less than 1.3 mm wide, with a spongy portion length of less than 1.1 mm. Carex retroflexa perigynia average 1.3 mm or more wide, with a spongy portion 1.1 mm long or longer.
Kudzu [Pueraria montana (Lour.) Merr. var. lobata (Willd.) Maesen and Almeida] is a perennial, semi-woody, climbing legume in the tribe Phaseoleae Benth., subtribe Glycininae Benth. (Maesen 1985, Maesen and Almeida 1988, Ward 1998). It is native to China, where an abundance of natural enemies (Pemberton 1988) and its cultivation prevent kudzu from becoming either an important economic or environmental liability. Kudzu was introduced to the United States as an ornamental during middle of the 19th century. During first half of the 20th century, approximately 134,760 ha were planted throughout the southeastern United States to feed livestock and for erosion control (Wheeler 1950). During 1998, kudzu was included by legislators in the United States Congress on a growing list of invasive, exotic plants recognized under the Federal Noxious Weed Law. Presently, it costs commercial forests approximately $119/ha annually (Beckwith and Dangerfield 1996), it compromises the integrity of valuable natural resources, and dense infestations have interfered with exercises on military bases in North Carolina, South Carolina, and Virginia (Al Cofrancesco, United States Army Corps of Engineers, Vicksburg, Mississippi, pers. comm.).
The Elizabeth Ann Bartholomew Award
Dr. James Schrader of Iowa State University is the recipient of the 13th annual Richard and Minnie Windier Award. This award is given to the author of the best plant systematics paper published during 2002 in Castanea.
Building upon the first author’s Wildflowers of the Carolina Lowcountry, now out of print, Professors Porcher and Rayner have expanded and improved their Guide to cover the entire state. Over 680 color prints illustrate species and communities, many of which have not been well-shown before.
Age and structural characteristics were measured in two frequently burned old-growth mountain longleaf pine (Pinus palustris Mill.) communities along Choccolocco Mountain in northeastern Alabama. Stands studied were open-canopied and park-like (8.3 to 13 m2 ha-1 basal area; 282-297 trees ha-1), fitting historical descriptions of the now endangered communities. Maximum pine ages in the two stands exceeded 240 years. Both stands underwent continuous pine recruitment over the past 145 years, with all 5-year age classes represented. Congregations of even-aged pine patches were found throughout both stands. Multiple tree patches ranged from 15 to 170 years old. Large even-aged patches were present in both stands (up to 2124 m2), though isolated single trees were more common, accounting for about half of all patches. Continued work on pristine remnant forests and savannas is necessary due to their increasing rarity and importance as reference models for management and restoration.
We inventoried two 1-ha plots on opposing watersheds (WS2-WS-S, WS18-WS-N) three times (1983, 1989, 1998) over a 16-year period to contrast how differing precipitation (P) regimes affect tree mortality. From 1983 to 1989, annual precipitation averaged 16.5% less than the 64-year mean; from 1989 to 1998, it averaged 12.2% above the mean. In 1989 and 1998, standing crop biomass, aboveground net primary productivity, mortality rates and species composition were determined. In 1989, following the dry period, the highest mortality for canopy tree species was in Carya spp. and Quercus velutina in both watersheds. Following the wet period in 1998, mortality was highest in Cornus florida in both watersheds, presumably due to the Anthracnose fungus; however, net change in stem density due to ingrowth was positive for this species in the WS-S watershed (+34%) and negative in the WS-N watershed (-18%). Estimated ANPP for WS-S was 10 and 1,076 kg ha-1yr-1 for the periods 1983-89 and 1989-98, respectively. In contrast, ANPP on WS-N was 679 and 93 kg ha-1 yr-1 for the same periods. Differences in ANPP are due to higher rates of mortality on WS-N compared with WS-S. In this study, species specific rates of mortality varied by watershed, and were likely due to microclimate-related increased susceptibility at the species level to certain proximal causes.
Amaranthus pumilus, a federally threatened species that inhabits the transient and highly variable barrier beach environment of the United States, has been extirpated from nearly three-fourths of its historic range. This study ascertained habitat requirements and determined how certain biotic and abiotic factors influence A. pumilus populations on Figure Eight Island, North Carolina. Data obtained were then compared to findings of Cakile edentula studies (C. edentula is common throughout the range of A. pumilus) in an effort to explain differences in range and abundance. Scarification and temperatures of 35℃ enhanced seed germination. The majority of A. pumilus plants were found on overwash fans. Mortality was greatest following storm periods that inundated seedlings through four tidal cycles. Density of seedlings had no affect on mortality rate. No evidence was found for biological control of A. pumilus populations. Maximum seedling emergence from burial by sand was less than 1 cm. Amaranthus pumilus populations on Figure Eight Island appeared to be physically rather than biologically controlled. Characteristics such as a shorter growing season and inability to emerge from depths greater than 1 cm may be adaptive disadvantages when compared with C. edentula.
Changing disturbance regimes, particularly decreasing fire frequencies, may result in distributional changes of species across southern Appalachian landscapes. Some researchers have hypothesized that Pinus strobus (eastern white pine) is undergoing a change in site affinity from mesic to xeric sites in southern Appalachian forests, but no studies have evaluated the landscape-level status of P. strobus. We examined the status of P. strobus in a 225-ha old-growth Quercus landscape within the Ellicott Rock Wilderness (ERW) in South Carolina by sampling 80 plots. Pinus strobus exhibited the highest mean density (267 trees ha-1) of all species in the 1-10 cm diameter class, with 96% of the P. strobus currently in these Quercus forests establishing since 1950. Density of P. strobus in the 1-10 cm diameter class was most highly correlated with P. strobus density >10 cm diameter, and was not strongly correlated with other measured vegetation variables such as total Quercus basal area. Results support the hypothesis that P. strobus is expanding its distribution to upland sites in the southern Appalachians. It is possible that the current P. strobus vegetation type observed in the ERW represents a vegetation type that historically would have occurred more extensively had it not been inhibited by Native American or lightning-caused fires.
Noteworthy Collections: District of Columbia