caa a22 4500 463168089 CHVBK 20180406164805.0 cr unu---uuuuu 170326e20071001xx s 000 0 eng 10.1007/s10530-006-9082-9 doi (NATIONALLICENCE)springer-10.1007/s10530-006-9082-9 Population life-cycle and stand structure in dense and open stands of the introduced tall herb Heracleum mantegazzianum [Elektronische Daten] [Jörg Hüls, Annette Otte, R. Eckstein] Populations of the introduced Heracleum mantegazzianum consist of dense central stands, which gradually give way to open stands towards the margins. To analyse whether open stands are due to unsuitable conditions or represent the invading front for further spread, we studied life-cycle, population dynamics, stand structure and soil conditions of open and dense stands over two transition periods. Populations decreased during the first interval but increased after the extremely dry and warm summer of 2003 during the second interval. Open stands had shorter generation times, lower height, smaller proportions of small individuals and were less in equilibrium with the environment than dense stands. In open stands, growth to higher stages was most important, while in dense stands delayed development (self-loops) had a strong effect on population growth; stasis and fecundity contributed most to the difference in λ between stand types. By petiole extension H. mantegazzianum may raise its leaves just above the resident vegetation. Therefore, younger stages develop faster in open stands, whereas strong competition by conspecific adults leads to longer generation times and a higher proportion of small individuals in dense stands. Disturbance due to extreme climatic conditions in summer 2003 equalised population dynamics of both stand types. Life-cycle variation between stand types makes it difficult to infer simple management rules. However, our data suggest that small and/or open stands of H. mantegazzianum may eventually serve as initials for further spread after land-use changes, whereas dense stands are stable and may represent sources of propagules. Springer Science+Business Media, Inc., 2007 Apiaceae nationallicence Elasticity nationallicence Intraspecific competition nationallicence Life table response experiment (LTRE) nationallicence Loop analysis nationallicence Management nationallicence Matrix models nationallicence Vital rates nationallicence Hüls Jörg Department of Landscape Ecology and Resource Management, Interdisciplinary Research Centre, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany aut Otte Annette Department of Landscape Ecology and Resource Management, Interdisciplinary Research Centre, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany aut Eckstein R. Department of Landscape Ecology and Resource Management, Interdisciplinary Research Centre, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany aut Biological Invasions Springer Netherlands 9/7(2007-10-01), 799-811 1387-3547 9:7<799 2007 9 10530 https://doi.org/10.1007/s10530-006-9082-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10530-006-9082-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hüls Jörg Department of Landscape Ecology and Resource Management, Interdisciplinary Research Centre, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany aut NATIONALLICENCE 700 1- Otte Annette Department of Landscape Ecology and Resource Management, Interdisciplinary Research Centre, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany aut NATIONALLICENCE 700 1- Eckstein R. Department of Landscape Ecology and Resource Management, Interdisciplinary Research Centre, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 26-32, 35392, Giessen, Germany aut NATIONALLICENCE 773 0- Biological Invasions Springer Netherlands 9/7(2007-10-01), 799-811 1387-3547 9:7<799 2007 9 10530 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer