Successful forest regeneration under a changing
Transcription
Successful forest regeneration under a changing
Successful forest regeneration under a changing climate ris Jansons, Ulrike Hagemann & FUTUREforest contributors [email protected] Forest regeneration is the most sensitive phase in all forest rotation cycle and also the point, where forester can have most of the influence to future of particular stand Climate is changing even the rate is slow and difficult to notice Climate is changing even the rate is slow and difficult to notice Mother Nature is magnifying the changes so we could notice them via short-living organisms Climate is changing even the rate is slow and difficult to notice Mother Nature is magnifying the changes so we could notice them via organisms with good dispersal ability Climate is changing even the rate is slow and difficult to notice Mother Nature is magnifying the changes so we could notice them via long-term trends of seasonal phenomenon Auni š, 2006; LOB Climate is predicted to change in different manner across the Europe Changes in mean annual temperature OC Changes in mean annual precipitation, % JRC PESETA Spatial variation remains even in fines scale Length of vegetation period now and changes by mid-century Bether et al., 2010 Notable uncertainty remains in predictions But as the changes is fact, that will affect our forests in future – we cant simply ignore it Even if the changes are Global, adaptation is always local Population is the unit of adaptation Advantages of natural regeneration • Preservation of locally adapted populations • Preservation of high genetic variability • Good adaptation to micro-sites • Undisturbed root development • Mostly low cost • Low investment risk Is the local population always adapted? As the changes are continuous – as closer to present the natural selection have operated, as better the adaptation shall be Different natural regeneration methods are suitable in different cases; they all also have not the same advantages in terms of adaptation Seed trees are producing seeds. Sometimes. Retention trees are producing seeds. Always. Other important constraints shall not be forgotten, while choosing natural regeneration Natural regeneration needs to be used intentionally and with KNOWLADGE Advantages of artificial regeneration • Controlled plant density • Predictable seedling production • High flexibility • Low management intensity • Option of introducing of improved seed or plant material (control the desirable traits) • Changing species and/or varieties/provenances (because there might not be desirable traits/adaptation capacity around) Use of seed orchard progenies Additional gain in comparison to progenies of forest stands, % 30 25 20 1. stage_21 1. stage_26 15 2. stage_32 10 5 0 Yield Branch thickness Trees, selected for seed orchards, have been grown and selected in conditions closer to those, that are predicted in future, than trees, that contributes to natural regeneration Suitability for future conditions can be even further improved, while shifting the seed zones and using the seed orchard material according to existing/predicted conditions Mother Nature cant do this trick Besides high genetic quality and adaptability, plant material have also high physiological quality, that could help to withstand the conditions at first years in forest Only vital, resilient and productive forests can lock away large amounts of carbon in trees and soil and produce timber for material and energetic use, thus storing carbon in wood products or replacing non-renewable energy sources. Therefore, the timely regeneration of (over-) mature and damaged forests using an adequate strategy is crucial for maintaining or restoring forest functionality Thank You ! ris Jansons [email protected]
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