Harz Living Lab, Germany

Responsible  institution:  Max Planck Institute for Biogeochemistry (MPI)

Introduction

The Harz, the northernmost low mountain range in Germany, spans the federal states of Lower Saxony, Saxony-Anhalt, and Thuringia. Stretching approximately 110 kilometers in length and up to 30 kilometers in width, it forms a striking landscape in central Germany. The Brocken, the highest peak of the Harz at 1,141 meters, is a well-known landmark for the region.

The local topography of the Harz creates significant variability in soils (i.e., nutrient and water availability) and climate, allowing for heterogeneous forest structures and a rich diversity in species composition.

The cultural richness of the region is characterized by the Harz spanning three federal states and numerous towns and municipalities, which fosters a variety of different approaches to alternative forest management options. Therefore, the Harz is an ideal landscape for establishing a forest living lab to develop climate-resilient and adaptable forests.

 

Figure 1: Overview of the Harz region, highlighting the Harz National Park (green) and party of the eastern state forestry company areas (yellow).
Figure 1: Overview of the Harz region, highlighting the Harz National Park (green) and party of the eastern state forestry company areas (yellow).

 

Climate

Situated in central Germany, the Harz region provides a temperate climate characterized by discernible seasonal fluctuations.

Winters in the Harz tend to be cold, often accompanied by sub-zero temperatures and frequent snowfall, particularly in higher altitudes. Summers, on the other hand, exhibit mild to moderately warm conditions, with temperatures ranging from pleasantly temperate to moderately hot. The transitional seasons of spring and autumn bring about moderate temperatures and sporadic rainfall, marking periods of transition.

Exposed to the rain-rich Atlantic westerly winds, up to 1,600 mm of rain falls annually on the windward side (Western Harz, Upper Harz, High Harz), while, mountain-typically, only about 600 mm of precipitation falls on the lee side on average each year (Eastern Harz, Lower Harz, Eastern Harz Slope).

The diverse terrain of the Harz engenders microclimates, characterized by nuanced differences in temperature, precipitation, and wind patterns across various locales. Valleys often exhibit cooler temperatures and elevated humidity levels, while exposed ridges and summits are subject to intensified winds and more pronounced climatic extremes.

Soil types

The soils in the Harz region exhibit considerable diversity due to variations in parent material, topography, climate, and vegetation cover. Broadly categorized, the predominant soil types found in the Harz include:

 

  1. Podzols: Podzols are acidic soils characterized by a distinct soil profile with distinct horizons. They typically develop under coniferous forests, such as those dominated by spruce, and are common in the higher elevations of the Harz. Podzols are known for their leached, sandy upper horizons and accumulation of organic matter and iron oxides in deeper layers.
  2. Brown Soils: Brown soils are fertile, well-drained soils that develop under deciduous forests and grasslands. They are characterized by a dark, organic-rich surface horizon (the A horizon) and a reddish-brown subsurface horizon (the B horizon) enriched with clay and iron oxides. Brown soils are prevalent in the lower elevations of the Harz and support diverse vegetation communities.
  3. Cambisols: Cambisols are soils that have undergone weathering and horizon development but lack the distinct characteristics of Podzols or Brown soils. They are common in areas with moderate weathering and are often found on slopes and hillsides in the Harz region. Cambisols exhibit a variable soil profile and support a wide range of vegetation types.
  4. Fluvisols: Fluvisols are alluvial soils that form in river valleys and floodplains. They are characterized by their high fertility and periodic deposition of silt, clay, and organic matter by flowing water. Fluvisols are found along the river valleys of the Harz, where they support intensive agricultural activities and wetland habitats.
  5. Regosols: Regosols are shallow soils with limited horizon development, often found on rocky slopes and steep terrain in the Harz. They are characterized by their rocky substrate and thin, poorly developed soil horizons. Regosols are typically less fertile than other soil types and are often subject to erosion.

These soil types play a critical role in supporting the diverse ecosystems and vegetation communities found in the Harz region, influencing plant growth, water retention, and nutrient cycling processes. Understanding the distribution and characteristics of these soils is essential for sustainable land management and conservation efforts in the area.

Forest Use

Forest use in the Harz is diverse and has a long tradition dating back to the Middle Ages. The Harz, as one of Germany's most significant forested areas, offers economic, ecological, and cultural value.

Historically, the Harz was a center of mining, and the forests were intensively exploited to provide timber for mine construction, energy for ore smelting, and charcoal production. This utilization led to extensive deforestation and has significantly shaped the current forest landscape.

Today, sustainable forestry is paramount. The Harz is characterized by coniferous forests, particularly spruces, which were commonly planted due to their rapid growth and economic importance. However, climate change has increased the vulnerability of these monocultures to storms, droughts, and pests such as the bark beetle, leading to significant forest losses in recent years.

The Harz National Park plays a central role in nature conservation and the preservation of natural forest landscapes. Here, the forest is largely left to develop naturally, creating valuable habitats for numerous animal and plant species. This not only contributes to biodiversity conservation but also provides important research areas for studying natural forest processes.

In addition to forestry and conservation, the Harz is a significant recreational area. Its forests offer extensive opportunities for outdoor activities such as hiking, cycling, and winter sports, making tourism an important economic factor for the region.

In summary, forest use in the Harz today is characterized by an integrative approach that combines sustainable forestry, nature conservation, and recreation. This multifunctional use is crucial for preserving the Harz forests for future generations and maintaining their diverse functions and values.

Forest Resilience Challenges

Although many forest areas in Germany face significant challenges due to climate change, the mid-mountain regions dominated by spruce trees are experiencing the highest forest losses nationwide, with losses in the Harz region reaching up to 80%. The large-scale die-off of forests in the Harz has numerous negative consequences for the region, including habitat loss and disruptions to water and nutrient cycles. For example, increased nutrient inputs from damaged forest areas into neighboring reservoirs lead to severe problems with drinking water supply, as seen with the Rappbode Reservoir in the Harz, one of Germany's largest reservoirs. A deterioration in water quality would therefore have both ecological and socio-economic impacts on the Harz.

The massive tree die-off in this region also presents significant challenges for tourism, the national park, forest owners, and forest management authorities: Developing strategies for a sustainable and socially accepted redesign of the forest. It is certain that the redesign or restructuring of the forest must, in addition to meeting the demands of societal, ecological, and economic interests, also address climate protection concerns in the region, in the wider surroundings, as well as at the national level.

Key Stakeholders

The stakeholders in the Harz region regarding the forest include a variety of interest groups that are affected by forest resources and activities in different ways. These include:

 

  1. Forestry companies and forest owners: This group includes state forestry enterprises, private forest owners, forestry companies, and timber industries involved in the management and utilization of forests in the Harz.
  2. Conservation organizations: Conservation organizations advocate for the protection and preservation of natural habitats in the Harz, including the promotion of protected areas such as the Harz National Park.
  3. Tourism industry: The tourism industry in the Harz benefits from the natural beauty and diversity of the forests, which are a major attraction for visitors. This includes hotels, restaurants, tour operators, and outdoor activity providers.
  4. Local communities and authorities: Local government agencies and communities in the Harz play a crucial role in the management and planning of forest resources, as well as in promoting economic development and environmental conservation in the region.
  5. Drinking water authorities: Drinking water authorities are responsible for ensuring the quality and availability of drinking water sources in the Harz region, including monitoring and managing water resources within forested areas.
  6. Citizens and local communities: The residents of the Harz and local communities have direct interests in the use and conservation of forest resources, whether through recreational activities, traditional uses, or protection from natural disasters such as wildfires and floods.
Key stakeholdersCategory
Forstbetrieb OstharzForest owner, political organ
PrivatwaldbesitzendeForest owner
Harz CountyForest owner, political organ
Nationalpark HarzForest management, education, conservation
Wernigerode Tourismus GmbHTourism
Quedlinburg-Tourismus-Marketing GmbHTourism
Harzklub e.V.Outdoor sports
BUND Sachsen-AnhaltConservation
Krisenstab WaldGovernmental interests
Harzwasserwerke GmbHWater service
Harzkreis residentsPublic