Biodiversity needs deadwood

These species use the deadwood for shelter, hibernation sites, breeding ground, and food sources. Since it takes years for wood to decompose completely and become deadwood, it provides a reliable habitat for even more species until decomposition has completed.  

The diversity of species increases significantly with the deadwood’s age, which is why older, heavily weathered branches and trunks should be removed. New branches can be cut and added to a shrunken brush pile to compensate for wood lost to the decomposition process.  

Deadwood attracts different organisms depending on the design of the garden and its location (shady/sunny, dry/wet). For example, reptiles and ants prefer sunny, dry locations.  

Deadwood connects different habitats. For example, piles of branches in shady locations or tree stumps near gardens ponds attract amphibians like frogs, toads, and newts because these species need both water and land for their life cycle.  

Ways to incorporate deadwood into gardens include: 

• Dead trees, stumps, and shrub roots 

• Fallen logs as borders for gardening beds or pathways 

• Layering logs or branches in a decorative fashion 

• Creating brush piles 

• Weaving brushwood into a privacy or boundary hedge (add climbing plants for more greenery) 

• Utilizing wood chips as a pathway or foundation for play equipment (swings etc.)  

Tip: Once wood material (brush piles etc.) has been stacked, it should be left alone completely and not further rearranged or shredded, as this is the only way for the decomposition process to proceed completely.  

The wood decay process can be divided into three main phases: 

• Colonization Phase: Pioneer insects such as beetles, as well as fungi colonize the wood, feeding on it and creating tunnels. The wood already starts to decay on a microbial level during this phase.   

• Decomposition Phase: Fungi and bacteria gradually decompose the wood while additional insect species settle in.  

• Humification Phase: The wood slowly disintegrates and becomes a part of the soil. Soil organisms such as worms, snails, woodlice, and millipedes infiltrate the decaying wood, further breaking down the substance. Fungi breaks down the cellulose and lignin from the wood. The decaying wood is finally transformed into humus thanks to the work of countless organisms.  

Wood decay is a slow process that takes different amounts of time depending on the type of wood and microclimate (temperature, humidity).