TY - GEN A1 - Zaplata, Markus Klemens A1 - Winter, Susanne A1 - Fischer, Anton A1 - Kollmann, Johannes A1 - Ulrich, Werner T1 - Species-driven phases and increasing structure in early-successional plant communities T2 - The American Naturalist N2 - Successional phases describe changes in ecological communities that proceed in steps rather than continuously. Despite their importance for the understanding of ecosystem development, there still exists no reliable definition of phases and no quantitative measure of phase transitions. In order to obtain these data, we investigated primary succession in an artificial catchment (6 ha) in eastern Germany over a period of 6 years. The data set consists of records of plant species and their cover values, and initial substrate properties, both from plots in a regular grid (20 m × 20 m) suitable for spatial data analysis. Community assembly was studied by analyses of species co-occurrence and nestedness. Additionally, we correlated lognormal and log series distributions of species abundance to each community. We here introduce a new general method for detection of successional phases based on the degree of transient spatial homogeneity in the study system. Spatially coherent vegetation patterns revealed non-overlapping partitions within this sequence of primary succession and were characterized as two distinct ecological phases. Patterns of species co-occurrence were increasingly less random, and hence the importance of demographic stochasticity and neutral community assembly decreased during the study period. Our findings highlight the spatial dimension of successional phases and quantify the degree of change between these steps. They are an element for advancing a more reliable terminology of ecological successions. KW - spatial analysis Y1 - 2013 U6 - https://doi.org/10.1086/668571 VL - Vol. 181 IS - 1 SP - E17 EP - E27 ER - TY - CHAP A1 - Zaplata, Markus Klemens A1 - Kollmann, Johannes A1 - Ulrich, Werner A1 - Winter, Susanne A1 - Schaaf, Wolfgang A1 - Elmer, Michael A1 - Gerwin, Werner A1 - Fischer, Anton ED - Jeltsch, Florian ED - Joshi, Jasmin T1 - Cover balance or degree of autocorrelation? It is the same and integratively traces pattern formation during succession T2 - GfÖ 43rd Annual Meeting, Building bridges in ecology, linking systems, scales and disciplines, September 9 to 13, 2013, Potsdam, Germany N2 - It is widely acknowledged that increasing complexity is a key attribute of ecosystem genesis. This is particularly true for primary succession on homogeneous substrates. However, a mechanistic understanding of spatial colonisation and pattern formation during primary succession has not been achieved yet. Thus, we studied this topic for 7 years within an experimental catchment (6 ha) established in the post-mining landscape of eastern Germany. Equidistant permanent plots (120 plots à 25m²) allowed for autocorrelation analyses, and thus tracing the spatial development of species cover performance. For each species tested, the “cover balance” first increased due to colonization, while decreasing in the course of succession. Drawing a benefit from these temporal trends, we suggested cover balance levels revealed by autocorrelation analyses to best indicate well-defined phases in primary succession at spatial entities. Hence, with the help of this spatial approach, terrestrial succession can be understood now much better at the most general level of the hierarchy provided by Pickett et al. (1987). In accordance with these authors, at subordinated levels of the causal hierarchy differential species performance might get collectively explained by contributing processes or conditions, such as ecophysiological traits, life history strategies, competition and allelopathy of the occurring plant species. Further research is needed to understand their relative contributions to the pattern formation. Y1 - 2013 UR - http://www.gfoe-2013.de/download/130905_GFOe_2013_Abstracts.small.pdf SP - 228 EP - 229 ER -