Shoot growth and distribution pattern ofCarex kobomugi in a natural stand

Abstract

To clarify the growth and distribution of Carex kobomugi, I surveyed the shoot heights and weights of a population growing in a sand dune at Sindu-ri, Wonbuk-myeon, Taean-gun, in Chungnam Province, Korea. During the growing season, size classes, based on leaf number and shoot heights, shifted, with those in the medium class moving to higher classes. Although the frequencies of those class characters showed a normal distribution curve throughout the season, the frequencies of each class based on shoot weight were evenly distributed in all size classifications. Coefficients of variation were 0.17 for leaf number, and 0.35 for leaf length and weight per plant. The maximum numbers of leaves were 8.16 _+ 1.38 per plant for those that were non-flowering, but 2.66 __. 0.62 per plant for those that did flower. Non-flowering plants exhibited withered leaves by mid-September, while withering began in male plants by mid-May and by mid-July for females. At the end of the growing season, the lengths and weights of leaves from non-flowering plants were 47.8 _ 16.6 cm and 1773 _+ 628 mg, respectively. When leaf order was considered, leaves increased in size along two-thirds of the ranking, then decreased. In a separate analysis, the growth of Carex plants was compared with those of Elymus mollis in the same sample quadrats. Biomass of the former accounted for only a small portion of the total biomass per unit area (E. mollis having a dry weight of >76.4 g m-Z), but under such competition, the leaf lengths and individual plant weights nonetheless increased for Carex as well.

Soil quality: a key factor in understanding plant invasion? The case of Carpobrotus edulis (L.) N.E.Br.

“…Most of the necessary and available nutrients for the growth of dune plants are contained in seawater (Min 2006), except for nitrogen and phosphorus, which occur at such small concentrations that coastal dunes show low concentrations of these macronutrients (Süb et al 2008;Pye and Tsoar 2009). Phosphorus is the second most important nutrient in the coastal dunes and pH has a direct influence on its availability: at high pH, phosphorus released precipitate as salts.…”