Core project 6: Forest structure - Properties, structure and management of the forest experimental plots

 

Scientific investigators:

Prof. Dr. Christian Ammer

Dr. Peter Schall

Dr. Laura Zeller

Dr. Martin Ehbrecht (assoc.)

Sylvia Bondzio

Karl-Heinz Heine

Andreas Parth

Michael Unger

(Uni Göttingen)

Forests are characterized by a highly variable compositional and spatial structure being extremely important for various ecological processes and the availability of resources and habitats. However, the specific structure of a forest stand is changed by stand development due to tree growth, ageing and competition, disturbances, and by forest management. Silvicultural interventions may do both, homogenize or diversify stand structure. Therefore, the assessment of stand structure and its quantitative description are crucial for understanding the impact of forest management on biodiversity and ecosystem functioning.

The forests of the Exploratories differ in respect to the applied methods of final harvest and stand replacement, tree species mixture, developmental phase, age structure, layering and patchiness. The managed forests of the Exploratories cover the entire spectrum and range from planted, even-aged, single-layered, monoculture stands of conifers (Norway spruce or Scots pine), to naturally regenerated, even-aged, single or double layered monoculture stands of broadleaves (European beech or oak) of various developmental phases, to even-aged man-made mixed forests, and to uneven-aged beech forests. Additionally, pure and mixed forests dominated by European beech, which have been unmanaged since some decades are studied.

 

Research focus

Within the framework of the Exploratories, this project serves to provide quantitative data for all experimental plots on 1) attributes of forest structure, 2) changes in attributes of forest structure due to forest management and natural processes, 3) stand development and productivity, 4) type and magnitude of forest management interventions, 5) deadwood amount and composition, and 6) abundance of tree microhabitats. This information may serve as explanatory variables for all teams working on functional biodiversity at the level of specific species, functional groups or multidiversity.

Additionally, we will further develop existing approaches of quantifying forest management intensity in order to analyse the relationship between forest structure and land use intensity.

Since 2019, we are involved in the new forest experiment FOX, and contributed to its design, planning and implementation.

 

Method

Our work is strongly based on inventories. That is, we locate, count and measure the objects of interest, be it living trees, dead wood items or habitats. Repeated inventories serve to quantify temporal changes, like tree growth or dead wood accumulation. Additionally, we rely on terrestrial laser scanning which allows quantitative descriptions of forest structure and space filling with plant material.

 

Work packages

In this phase (6th phase, 2020 - 2023) we will:

Experimental plots - EPs

  • conduct the 3rd repeated large trees inventory
  • conduct the 2nd laser scanning inventory
  • monitor browsing damage
  • quantify forest growth, tree harvests and other causes of tree mortality
  • quantify the dynamics of stand structure

 

New forest experiment - FOX

  • document characteristics of deadwood logs
  • sample deadwood logs by drilling
  • monitor canopy closure by laser scanning
  • monitor the root development in the canopy ga
  • monitor tree regeneration

 

In the previous phase (4th phase, 2017 - 2020) we:

Experimental plots - EPs

  • surveyed dead wood items (6436 deadwood items)
  • surveyed tree microhabitats (5409 microhabitats on 5985 trees)
  • monitored browsing damage
  • analysed temporal changes in stand structure and land use intensity
  • analysed temporal changes of land use intensity

 

New forest experiment - FOX

  • designed the FOX Forest Experiment
  • inventoried the FOX-plots
  • planned the gap cutting
  • planned the deadwood enrichment

In the previous phase (4th phase, 2014 - 2017) we:

  • completed and processed the initial large trees inventory (2nd and 3rd phase)
  • contrasted terrestrial and airborne data
  • conducted the repeated large trees inventory (70453 trees)
  • inventoried small trees (dbh < 7 cm, 97177 trees)
  • monitored browsing damage (14990 trees)
  • provided data on forest characteristics, stand structure and land use intensity
  • quantified forest growth, tree harvests and other causes of tree mortality
  • prepared a synthesis paper on the impact of even- aged and uneven-aged forest management on regional biodiversity in European beech forests

Project in previous phases

Further project contribution of Prof. Christian Ammer: KnowledgeTransferProject

Previous project contribution of Prof. Christian Ammer: SHAPE, Neighbor

Previous project contribution of Dr. Peter Schall: Neighbor

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