Distribution and morphological variations of invasive macrophytes Elodea nuttallii (Planch.) H. St. John and Elodea canadensis Michx in Croatia
نویسندگان
چکیده
The invasive species Elodea nuttallii was recorded for the fi rst time in the Croatian fl ora in 2006, in the drainage channels of Kopački rit (Baranja). After its establishment, E. nuttallii begins to spread to the eastern and northern part of the drainage channel network from 2006–2009. High water levels are responsible for the linear spreading direction of E. nuttallii, E. nuttallii and E. canadensis show a wide range of morphological variation, which is characteristic of successful invaders. To show morphological variations of two Elodea species, the most impor tant characters indicated in the literature were measured on 24 fresh collected samples from the seven sites in Croatia. In spite of some overlap in leaf length and width between the two Elodea species, the differences of all morphological traits except internode length are statistically signifi cant. In E. nuttallii leaf width, length and internode length show a higher morphological variability as a result of the higher adaptive strategy to environmental parameters. The most reliable morphological characters distinguishing E. nuttallii and E. canadensis are leaf width 0.5 mm below the tip and the angle at the apex. E. nuttallii can be expected to spread to other areas of Croatia.
منابع مشابه
Comparative Analyses of Plastid Sequences between Native and Introduced Populations of Aquatic Weeds Elodea canadensis and E. nuttallii
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Since Elodea nuttallii (Planch.) St. John was introduced to Europe from North America in 1939 it has invaded many water bodies and is widely spread over the continent. Its success is usually related to ease of adaptation to several environmental factors (DENDÈNE et al. 1993, JONES et al. 1993, OZIMEK et al. 1993, SIMPSON 1990). Our research, however, indicates that chemical defenses may play an...
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