Reforestation techniques in the Mediterranean - woody plant propagation and establishment Bachelor thesis to gain the Bachelor of Science degree (B.Sc.) in International Forest Ecosystem Management at the Eberswalde University for Sustainable Development University of Applied Sciences presented by Jochen Baumgärtner born October 31, 1981 in Gunzenhausen, Germany Bachelor thesis adviser: Dr. Bernhard Götz 1. Evaluator: Dr. Bernhard Götz 2. Evaluator: B.Sc. Christoph Ulbig Eberswalde. August 14, 2012 Summary Summary This thesis aims to give an overview on the status quo of mediterranean forest and woodland restoration techniques and practices with a main focus of propagation and establishment of woody plants in the Mediterranean as well as to synthesize recent findings in correlating sciences. Mediterranean forest and woodland ecosystems have undergone a long period of degradation. Most of the restoration programs of the last century failed due to deficiencies in understanding the ecosystem processes as well as inadequate species selection, nursery practices and plantation techniques. In the last two decades, much progress has been made in the fields of priority-setting in restoration programs. Immediate action after mayor disturbances like wildfires, i.e. through direct seeding combined with mulching has proven to decrease soil erosion. Through certification of seed and provenance, more vital and site-specific seed is available. Techniques like the selection of appropriate growing medium, progress in the design of containers for deep rooting species like Quercus spp., drought preconditioning and a better understanding of the effects of the time of planting resulted in better survival rates of planted seedlings. Site preparation techniques like subsoiling or tillage to increase the amount of rootable soil, and higher water availability through amendments and water and fog harvesting techniques increased recruitment in test- plantations. A deeper understanding of plant-plant interactions and succession dynamics open-up new possibilities for using shrubs or trees as nurse plants as well as for the restoration of forests landscapes in multi-step approaches. So far, most of this progress is still on an experimental level, but a combination of several techniques bears potential to restore Mediterranean forest and woodland landscapes successfully while making them more resilient for coming challenges like Climate Change. i Table of Content Table of Content Summary .............................................................................................................................. i Table of Content .................................................................................................................. ii List of Figures ..................................................................................................................... iv List of Tables ....................................................................................................................... iv Abbreviations ...................................................................................................................... v 1. Introduction ................................................................................................................. 1 2. Methods ...................................................................................................................... 2 2.1. Methods .............................................................................................................. 2 2.2. Setting the scene: The Mediterranean ............................................................... 3 2.2.1. The Mediterranean biome .......................................................................... 3 2.2.2. Climate in the Mediterranean ..................................................................... 4 2.2.3. Soils in the Mediterranean .......................................................................... 5 2.2.4. Vegetation in the Mediterranean ............................................................... 5 2.2.5. The role and risks of fire in Mediterranean ecosystems ............................. 6 2.2.6. Climate change in the Mediterranean ........................................................ 7 2.2.7. Degradation and the need for reforestation in the Mediterranean ........... 8 3. Results ....................................................................................................................... 11 3.1. Definition of ecological restoration and forest restoration .............................. 11 3.2. Brief history of Mediterranean woodland restoration ..................................... 11 3.3. Setting restoration priorities ............................................................................. 13 3.4. Passive restoration ............................................................................................ 14 3.5. First-aid restoration ........................................................................................... 14 3.6. State of the art in Mediterranean woodland restoration ................................. 15 3.6.1. Species selection ....................................................................................... 15 3.6.2. Direct seeding ............................................................................................ 16 3.6.3. Seedling production in nurseries............................................................... 17 3.6.3.1. Quality and origin of seeds ...................................................................... 17 3.6.3.2. Growing medium ..................................................................................... 17 3.6.3.3. Containers ............................................................................................... 18 3.6.3.4. Preconditioning ....................................................................................... 19 3.6.4. Enhancing seedling survival in the field .................................................... 20 3.6.4.1. Time of planting ....................................................................................... 20 3.6.4.2. Site preparation ....................................................................................... 20 3.6.4.2.1. Soil preparation ............................................................................. 20 3.6.4.2.2. Water availability .......................................................................... 20 3.6.4.2.3. Nutrient availability ....................................................................... 22 3.6.4.3. Tree shelter.............................................................................................. 22 3.6.4.4. Facilitation by nurse plants...................................................................... 23 3.7. Successional approaches ................................................................................... 24 3.7.1. Successional agroforestry ......................................................................... 24 3.7.2. Miyawaki method ...................................................................................... 26 ii Table of Content 4. Discussion .................................................................................................................. 27 4.1. Discussion of methods ...................................................................................... 27 4.2. Discussion of results .......................................................................................... 28 4.2.1. Reforestation ............................................................................................ 28 4.2.2. Brief history of Mediterranean woodland restoration ............................. 29 4.2.3. Setting restoration priorities ..................................................................... 29 4.2.4. Passive restoration .................................................................................... 30 4.2.5. First-aid restoration .................................................................................. 30 4.2.6. State of the art in Mediterranean woodland restoration ......................... 32 4.2.6.1. Species selection ..................................................................................... 32 4.2.6.2. Direct seeding .......................................................................................... 32 4.2.6.3. Seedling production in nurseries ............................................................ 33 4.2.6.3.1. Quality and origin of seeds ........................................................... 33 4.2.6.3.2. Growing medium .......................................................................... 34 4.2.6.3.3. Containers ..................................................................................... 34 4.2.6.3.4. Preconditioning ............................................................................. 35 4.2.6.4. Enhancing seedling survival in the field .................................................. 35 4.2.6.4.1. Time of planting ............................................................................ 35 4.2.6.4.2. Site preparation ............................................................................ 36 4.2.6.4.2.1. Soil preparation ...................................................................... 36 4.2.6.4.2.2. Water availability .................................................................... 36 4.2.6.4.2.3. Nutrient availability ...............................................................