Author/Editor		Germ, Mateja
Title		Močvirska spominčica in lasastolistna vodna zlatica v spremenljivem okolju
Translated title		Water forget-me-not and water buttercup in the variable environment
Type		članek
Source		In: Gaberščik A, editor. Jezero, ki izginja: monografija o Cerkniškem jezeru. Ljubljana: Društvo ekologov Slovenije,
Publication year		2002
Volume		str. 107-15
Language		slo
Abstract		Amphibious plants M. scorpioides and R. trichophyllus grow luxuriantly in the lake and in its tributaries, where the water-level fluctuates a great deal. Amphibious plants have a unique ability to photosynthesise under contrasting conditions in aquatic and terrestrial environments. Both environments differ in many ways, especially in the level of UV B radiation, an important factor, which accompanied transition of plants from the aquatic to terrestrial environment. The aim of the study was to examine the influence of the changeable environment on the amphibian species Myosotis scorpioides and Ranunculus trichophyllus. Experiments were carried out in the natural environment of the Lipsenjščica stream, the lake's tributary. The change of the medium did not effect the concentration of chlorophyll and the amount of UV B absorbing compounds in M. scorpioides and R. trichophyllus. On the other hand, it affected the physiology of both species. The higher respiratory potential of the plants growing in water indicates, as far as M. scorpioides is concerned, that the terrestrial environment is more suitable for this species. The aquatic specimens of R. trichophyllus performed higher respiratory potential than the terrestrial plants. This enables sustainment plans in the unfavourable environment. Comparison of both species revealed much higher amount of UV B absorbing compounds in the leaves of M. scorpioides than in R. trichophyllus. These imdings also support the hypothesis that M. scorpioides is "more" terrestrial than the aquatic plants. Through history, the secondary transition to water, phytochemical traits of plants, changed. Studies of many plants show that in the aquatic environment quality and quantity of secondary substances reduce. Flavonoids, which function as a filter for UV B radiation, are one of these substances. (Abstract truncated at 2000 characters)
Descriptors		FRESH WATER PLANTS ECOSYSTEM PHOTOSYNTHESIS