The germination characteristics of various broadleaf species as a factor of topsoil conditions in beech dominated mixed broadleaf forests on calcareous sites

Summary

In order to study the germination characteristics of beech and a number of associated species, namely sycamore, wild cherry, wych elm, ash and hornbeam, the seeds of each species were collected from seed traps, as well as from other appropriate sources and tested in various ways. The goal of leaf and seedfall experiments carried out in beech dominated mixed broadleaf stands subject to differing management regimes is to provide information in relation to the depth of litter layers and the location of seeds in these layers. One aspect of the study was to test the germination capacity of seeds immediately following seedfall. Additionally, seeds of different species were sown during the winter period and monthly germination tests were carried out to determine the alteration in the germination capacity of the seeds from autumn to spring. The germination capacity of the sown seed material was also studied in a number of different laboratory tests to serve as a comparison with the results obtained from the sowing experiment. Seed sowing experiments on different topsoils ran parallel to the aforementioned studies, under controlled conditions in a greenhouse, under semi-natural conditions in an arboretum, and under natural conditions with varying canopy conditions on a research site on the Schwäbischen Alb. The aim of these studies was to quantify the effect of soil type and the beech dominated litter layer on the germinant crop, as well as on the mortality rates and causes for each of the individual species.

Researcher:  Klaus Zimmermann

Supervisor:     Prof. Dr. Jürgen Huss