- KOREAN
- P-ISSN2287-8327
- E-ISSN2288-1220
- SCOPUS, KCI
ISSN : 2287-8327
Vol.30 No.3
Abstract
The mating systems of natural populations ofPotentila freyniana in Korea were determined usingalozyme analysis. The result sugests that P. freyniana is outcrosing as wel as employing vegetative repro-duction by stolon (self-fertilization rate, s < 0.5). The values of the inbreding coeficient of eight populationsin Korea varied from 0.24 to 0.31, with an average value of 0.274. For eight natural populations, multi-locusestimates of outcrosing (tm) was 0.603 acros 13 polymorphic loci, with individual population values rangingfrom 0.530 to 0.652. The relatively low outcrosing rates ofsome populations could be atributed to extensivevegetative reproduction by stolon and the isolation of lowering mature plants. Although P. freyniana usualypropagated by asexualy-produced ramets, I could not rule out he posibility that sexual reproduction ocuredat a low rate because ach ramet may produce terminal flowers . Although eterozygote xces was observedin some natural populations, most populations exhibited varying degres of inbreding and a heterozygote deficit.
Abstract
This tudy examined the decomposition of blades and culms of aquatic emergent plant species,Zizania latifolia, Phragmites comunis and Typha ngustata , and changes in utrient contents during decom-position. Z. latifolia,P. comunis and T. angustata were the most frequently ocuring species in Lake Paldangof Han River, Korea. Experiments were caried out from July 27 to December 14, 205 in Lake Paldang usingthe liter bag method. The remaining mases of blade liter of each species at he nd of experimental periodwere 21.2% of initial dry weight in Z. latifolia, 32.5% in P. comunis , and 4.7% in T. angustata. In adition, theremaining mas of culm was 2.6% of initial dry mas in Z. latifolia, 56.4% in P. comunis , and 38.1% in T.angustata . During the liter decomposition period, P, K, Na, and Mg concentration decreased rapidly within 10days, but Ca nd Mn concentration declined slowly. K content s remained below 10% of initial values in al itersamples retrieved uring decomposition, whereas Ca nd Mg c oncentration remained above 40% and 50%during decomposition in al thre species. Na, P and Mn conte nts in liter varied among species and plant parts.P concentration in culms ofP. comunis remained at about 60% of initial concentration throughout he study,but he remaining P content in culms of Z. latifoliawas only 10% of the original value at he nd of the studyperiod. The Mn concentration in blades of P. comunis increased about 15-fold relative to the initial contentby the nd of experiment.
Abstract
We investigated the foraging habitat preferences of heronsand egrets in an agricultural area inAsan city, Chungcheongnam-do, Korea. In the study area, rice fields were the most abundant habitat ype (86.8%)and total suitable feding habitat was greater in the northern area (59.0%) than the southern area (2.5%) ofthe colony. Most feding herons and egrets were located in the northern area of the colony. The number offeding individuals in a given area was related to the availa ble feding area (Pearson corelation, r=0.73,p< 0.01 for field habitats;r=0.901, p< 0.01 for freshwater habitats). Feding habitat preferences difered amongspecies. Grey herons (Ardea cinerea ), great egrets (Egreta lba ), and black-crowned night herons (Nycticoraxnycticorax) used reservoirs and itches. However, intermediate gret s (E.intermedia ) and catle grets ( Bubulcusibis ) were dependent on rice fields. The litle gret ( E. garzeta ) was a habitat generalist using al types ofhabitats. The two largest species, grey herons and great egrets, fed at deper site than litle grets and foragedin deper sites in reservoirs than in ditches (.2-test,.23=26.6 and p< 0.01 for grey herons, .23 =17.5 andp< 0.01 for great egrets). Al species displayed seasonal changes in feding habitat use and these changes wererelated with changes in availability of eding habitats.
Abstract
Pinheiro F, Diniz IR, Coelho D, Bandeira MPS 202. Seasonal paternof insect abundance in the Brazilian cerado. Aust Ecol 27: 132-136.Price PW. 197. Insect Ecology, 3rd ed. John Wiley & Sons, NewYork.Raimondo S, Turcani M, Patoeka J, Liebhold AM. 204. Interspecificsynchrony among foliage-feding forest Lepidoptera species andthe potential role of generalist predators as ynchronizing agents.Oikos 107: 462-470.Seaby RMH, Henderson PA. 206. Species Diversity and Richnes IV.Measuring and understanding biodiversity. Pisces, Lymington.Shapiro AM. 1975. The temporal component of buterfly species diver-sity. In: Ecology and evolution of comunities (Cody ML, Dia-mond JM, eds). Harvard Univ. Pres, p. 181-195.Shin YH, Kim S, Kim HC. 1989. Notes on the Lepidoptera of Mt.Wolchul, Cholanam-do, Korea. Rept Korean Asociation for
Abstract
Self-thining was measured in Salix comunities on Bam Island in Seoul at various age stages.D2H was used to estimate tre biomas, where D is tem diameter at breast height or 10 cm height for plantswith eight <1.5 m, and H is height. A log-log plot of density versusD2H and corelation analysis indicated asignificant relationship betwen density and biomas with equation 'log D2H = .1.27 log N + 7.06'. This indicatesthat self-thining afects biomas in the Salix comunity with .1.27 as the thining coeficient. If we asumea thining exponent .3/2, then the alometric oeficient of the quation, log w = a log D2H + b, is 1.18. Thisis much igher than that for any other species tudied in Kore a. There were statisticaly significant relationshipsbetwen age and ensity and betwen age and basal area nd the se relationships ugest guidelines fortransplantation of wilows and for the asesment of Salix comunity restoration projects in riverine wetlandsbased on standard ensity, basal area, and age. The results o f this tudy may also increase understanding ofsucesion proceses in Salix comunity restoration in riverine wetlands.
Abstract
Over-expresion of a coper/zinc superoxide dismutase (Cu /ZnSOD) resulted in substantialyincreased tolerance to cadmium exposure in Arabidopsis thaliana . Lower lipid peroxidation and H 2O2 acu-mulation and the higher activities of H2O2 scavenging enzymes, including catalase (CAT) and ascorbateperoxidase (APX) in transformants (CuZnSOD-tr) compared to untransformed controls (wt) indicated thatoxidative stres was the key factor in cadmium tolerance. Although progresive reductions in the dark-adaptedphotochemical eficiency (Fv/Fm) and quantum eficiency ield were observed with increasing cadmium levels,the chlorophyl fluorescence parameters were les marked in CuZnSOD-tr than in wt. These observationsindicate that oxidative stres in the photosynthetic aparatus is a principal cause of Cd-induced phytotoxicity,and that Cu/ZnSOD plays a critical role in protection against Cd-induced oxidative stres.
Abstract
ABTRACT: The loss of nitrogen and phosphorus from sediments in two watersheds, one naturally regenerating and one artificially planted, in Sacheon-myun, Gangneung-si, Gangwon Province, were measured two years after a forest fire in 2000. Sediment losses occurred five times in the course of the year. In the artificially planted watershed, 50～140 times more nitrogen and 54～139 times more phosphorus were lost with sediments during heavy rains, from July to August, than in the naturally regenerating watershed. When the typhoon Rusa struck the country, 1,389 times more nitrogen and 1,647 times more phosphorus were lost from the artificial watershed. In spite of the limited scope of this study, these results suggest that artificially planted watersheds are extremely vulnerable to catastrophic natural disasters such as typhoons. Elevated loss of nutrients in the artificially planted watershed might have resulted from the mechanized silvicultural practices employed immediately after the fire. To maximize soil preservation, the timing and necessity of plantation practices should be reconsidered, and rapidly regenerating vegetation should be protected to promote nutrient uptake and to mitigate nutrient loss from burned forests.
Abstract
A simple and eficient protocol was developed for culturingCu-tolerant and Cu-acumulating plantsvia pre-adaptation to Cu during plant isue culture. We ind uced multiple shots from begonia ( Begoniaevansiana Andr.) leaf explants on MS medium suplemented with naphtaieneacetic acid and benzyladenine.After 3 months, smal plantlets were transfered to MS medium suplemented with 10 . M CuCl 2 for pre-adap-tation to Cu and cultured for 5 months. Then, these plantletswere individualy planted in pots containing artificialsoil. An aditional 50 mg of Cu disolved in 1/4 strength MS s olution was aplied to each pot during irigationover the course of 2 months. We planted pre-adapted and control begonias in soil from the Il-Kwang Mine, anabandoned Cu mine in Pusan, Korea, to examine their ability to tolerate and acumulate Cu for phytore-mediation. Pre-adapted begonias acumulated 1,20 . g Cu/g dry rot isue over the course of 45 days. Onthe other hand, non-Cu-adapted controls acumulated only 85 . g Cu/g dry rot isue. To enhance Cuextraction, chelating agents, ethylenediamine tetracetic acid (EDTA)-dipotasiun and pyridine-2,6-dicarboxylicacid (PDA), were aplied. While the chelating agents did notenhance acumulation of Cu in the rots of controlbegonias, EDTA aplication increased the level of Cu in the rots of pre-adapted begonias twofold (to 2,50. g Cu/g dry rot isue). Because pre-adapted begonias acum ulated a large amount of Cu, mainly in theirrots, they could be used for phytostabilization of Cu-contaminated soils. In adition, as a flowering plant,begonias can be used to create aestheticaly pleasing remed iation sites.
Abstract
Social spiders consistently show highly female-biased sex ratios. However, the sex ratio fsubsocial spiders, which ave ben sugested as an intermed iate stage of the volutionary pathway towardspermanent sociality, is generaly unknown. We investigated the sex ratio and aproximate date of ertilizationof the subsocial spider, Amaurobius ferox Walckenaer (Araneae: Amaurobidae). Investigation over 2yearsrevealed that sex ratio f A. ferox was consistent acros years and averaged 0.49. By early May (1st 10th ),6.6% of emale A. ferox observed in the field had already ben inseminated, and by la te May (21st 31st),95.4% of emales had ben inseminated. This result sugests that A. ferox ned a long time or coldtemperatures to prepare them for eproduction after the developmental atainment of the adult stage.