@article {125,
	title = {Plant size and fertility of Isoetes lacustris L. in 20 lakes of Scandinavia: A field study},
	journal = {Archiv fur Hydrobiologie},
	volume = {139},
	year = {1997},
	note = {Cited By (since 1996):7Export Date: 11 November 2013Source: Scopus},
	month = {1997///},
	pages = {171 - 185},
	abstract = {A relationship between the individual size and fertility of Isoetes lacustris in the habitat centres of different lakes was found. The maximum (mean) rosette size was 202.2 cm2 and the maximum (mean) number of macrospores in a sporangium was 113.4; the minimum (mean) values were 13.8 cm2 and 30.6 spores. Further correlations between vitality and fertility parameters were established. It is suggested that the main ecological factors responsible for the differences found in the lakes are effects of climate (including water temperature and duration of seasonal growth), which cause the differences in rosette size and fertility. The percentage of individuals with fertile sporangia was lowest in the slightly humic lakes with boreal climate and short summers, and highest in the clear lakes with temperate climate and long summers. Isoetes individuals showed increased size with depth.},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0343052607\&partnerID=40\&md5=3be747f4cb73f24bc9d8880018c16bd1},
	author = {V{\"o}ge, M.}
}
@article {126,
	title = {Number of leaves per rosette and fertility characters of the quillwort (Isoetes lacustris L.) in 50 lakes of Europe: A field study},
	journal = {Archiv fur Hydrobiologie},
	volume = {139},
	year = {1997},
	note = {Cited By (since 1996):10Export Date: 11 November 2013Source: Scopus},
	month = {1997///},
	pages = {415 - 431},
	abstract = {Isoetes lacustris L. was studied in 35 lakes in the main area of distribution (N and W Europe), plus some other lakes outside of this area, where the species is present. By using SCUBA equipment fertile plants were selected randomly and several morphological and fertility characters were studied. It was found that there was a relationship between: a) the (mean) number of leaves per rosette, and the (mean) number of spores per macrosporangium, b) the number of leaves, and the number of macrosporangia per plant. The number of spores per macrosporangium is related directly to the percentage of fertile plants in the part of the population studied. A low number of leaves per rosette is a fair indication of a low number of macrospores in a sporangium and also a low number of macrosporangia per plant, anti the low number of spores points to a low percentage of fertile individuals in the part of the population studied. It is suggested that the often rapid decline of quillwort in lakes of Central Europe may be a self-accelerating process. In the N European lakes, numbers of leaves and spores have an inverse relationship to the colour of the water. In the W European lake sites, the height of the rosettes is correlated to the Secchi depth. No relationship between plant features and water characteristics (pH and conductivity) were found.},
	url = {http://www.scopus.com/inward/record.url?eid=2-s2.0-0342617829\&partnerID=40\&md5=e5b61ab9a7b00c72dbe6bce9554fbc2f},
	author = {V{\"o}ge, M.}
}
