Tree Vitality and Forest Health: Can Tree-Ring Stable Isotopes Be Used as Indicators?

Abstract Purpose of Review Society is concerned about the long-term condition forests. Although a clear definition forest health still missing, to evaluate health, monitoring efforts in past 40 years have concentrated on assessment tree vitality, trying estimate photosynthesis rates and productivity. Used decline Central Europe since 1980s, crown foliage transparency has been commonly believed be best indicator relation air pollution, although annual variations appear more closely related water stress. not good rates, defoliation one most used indicators vitality. Tree rings often as However, growth trends are difficult interpret because sampling bias, ring width patterns do provide any information physiological processes. Recent Findings In two decades, tree-ring stable isotopes only reconstruct impact climatic events, such drought, but also study induced by pollution episodes, other natural disturbances environmental stress, pest outbreaks wildfires. They proven useful tools for understanding processes response stress factors. Summary Tree-ring integrate transpiration may enhance our promising We call use future programmes.