Nurse structures effectively improve the performance of restoration plantings: a systematic review
Klaus Kremer, Sarah Holtkamp, Bengt‐Gunnar Jonsson, Jürgen BauhusAbstract
Introduction
Tree planting for ecosystem restoration often occurs on disturbed, degraded, or former agricultural sites, where seedlings face harsh conditions like sun exposure, drought, wind, frost, and browsing, which can lead to poor performance. To improve survival and growth, nurse structures such as nurse plants, plant residues, or artificial shelters may be used to buffer environmental stress.
Objectives
We aimed to assess how different nurse structures influence the performance of restoration plantings and how this effect varies with climate and environmental stressors, nurse structure type, plantation age, and tree species traits.
Methods
Using descriptive statistics and meta‐analyses, we systematically reviewed 82 studies from temperate and boreal forests addressing effects of nurse structures on the performance of planted trees.
Results
Nurse structures improve the performance of planted seedlings or saplings, particularly by enhancing survival and height growth. However, their effects on diameter growth and plant water status tend to be negative. The effects are consistent across tree species types but are stronger in temperate and continental climates, in younger plantations, and when using artificial shelters rather than nurse plants. Nurse structures are most effective at mitigating drought, frost, and browsing, while evidence for impacts on competition or wind is inconclusive.
Conclusions
Survival and growth of planted seedlings are improved through nurse structures. However, their effectiveness is context‐dependent, so site‐specific conditions should be considered when applying them for restoration purposes.