Canopy and soil interaction with deposition in remote boreal forest ecosystems: a long-term integrated monitoring approach.

Dissertation + appendices

Forest condition monitoring under the UN/ECE and EU programmes in Finland

Part of the online report: Merilä, P. & Jortikka, S. (eds.). Forest Condition Monitoring in Finland – National report. The Finnish Forest Research Institute. http://urn.fi/URN:NBN:fi:metla-201305087568. Original webpages have been converted to a PDF file

Metsien hiilensidonta, metsätalouden vesistökuormitus ja monimuotoisuus : tukimahdollisuuksia metsänomistajalle

Metsä toimii kasvaessaan tehokkaana hiilinieluna ja sitoo merkittävän osan Suomen kasvihuonekaasupäästöistä. Ilmakehässä olevan hiilidioksidin sitoutuminen metsiin on suoraan suhteessa metsien kasvuun. Metsänomistajalle hiilensidonta ja monimuotoisuuden suojelu markkinaehtoisesti voivat olla tapa laajentaa ansaintamahdollisuuksia omasta metsästään. Tähän esitteeseen on koottu tämän hetken yleistietoa metsien hiilensidontaan ja päästövähennyksiin liittyvistä mahdollisuuksista sekä aiheeseen liittyvistä metsätalouden tuista. Mukana on myös tietoa ja linkkejä ekologisen kompensaation mahdollisuuksista ja mm. hiilikaupan keskeisistä käsitteistä

Post-drainage stand growth and peat mineralization impair water quality from forested peatlands

Many recent studies have indicated upward trends in carbon and nutrient concentrations from drained peatland forests over time since their initial drainage, but the mechanisms behind these trends are still poorly understood. We gathered data on nitrogen and phosphorus concentrations discharged from 37 drained boreal peatland forests where we also had data on peat and tree stand characteristics. We found that tree stand volume and peat bulk density were positively correlated with the nitrogen and phosphorus concentrations discharged from particularly the deep-peated sites. We interpret these results to indicate that a plausible reason for the reported upward trends in nutrient concentrations is the maturing and growing of the tree stands over time since initial drainage and the consequent increasing evapotranspiration capacity, which results in lowered soil water levels and enhanced aerobic peat mineralization. We discuss how our results should be considered in the management of drained peatland forests

Increased evidence of nutrient imbalances in forest trees across Europe

202

Exploring the Role of Weather and Forest Management on Nutrient Export in Boreal Forested Catchments Using Spatially Distributed Model

Weather-driven hydrological variability and forest management influence the nutrient export from terrestrial to aquatic systems. We quantified the effect and range of variation in total nitrogen and phosphorus export in Vehka-Kuonanjärvi catchment located in southeastern Finland. A distributed model NutSpaFHy was used with varying weather scenarios (compiled from observed extreme years of dry, wet and wet & mild) and forest management scenarios (including no additional management and intensive clear-cutting of all mature stands in the existing forest structure). Nutrient exports by scenario combinations were compared to modeled baseline export in observed weather. The results showed that the increase in nutrient export by wet & mild weather (over 55%) exceeded the increase caused by the clear-cutting scenario (23 %). Dry weather decreased the exports to tenth of the baseline, which was per hectare 2.22 kg for N, 0.08 kg for P). The results suggest that in future maintaining a good ecological status in aquatic systems can be challenging if extreme wet years with mild winters occur more frequently. Certain catchment characteristics, e.g., deciduous tree percentage, open area percentage and site fertility, influence the export increase induced by the extreme weather. Hotspot analysis enabled identifying areas with currently high nutrient export and areas with high increase induced by the extreme weather. This helps targeting water protection efficiently

Effect of clear-felling and harvest residue removal on nitrogen and phosphorus export from drained Norway spruce mires in southern Finland

201

Exploring the Role of Weather and Forest Management on Nutrient Export in Boreal Forested Catchments Using Spatially Distributed Model

Weather-driven hydrological variability and forest management influence the nutrient export from terrestrial to aquatic systems. We quantified the effect and range of variation in total nitrogen and phosphorus export in Vehka-Kuonanjärvi catchment located in southeastern Finland. A distributed model NutSpaFHy was used with varying weather scenarios (compiled from observed extreme years of dry, wet and wet & mild) and forest management scenarios (including no additional management and intensive clear-cutting of all mature stands in the existing forest structure). Nutrient exports by scenario combinations were compared to modeled baseline export in observed weather. The results showed that the increase in nutrient export by wet & mild weather (over 55%) exceeded the increase caused by the clear-cutting scenario (23 %). Dry weather decreased the exports to tenth of the baseline, which was per hectare 2.22 kg for N, 0.08 kg for P). The results suggest that in future maintaining a good ecological status in aquatic systems can be challenging if extreme wet years with mild winters occur more frequently. Certain catchment characteristics, e.g., deciduous tree percentage, open area percentage and site fertility, influence the export increase induced by the extreme weather. Hotspot analysis enabled identifying areas with currently high nutrient export and areas with high increase induced by the extreme weather. This helps targeting water protection efficiently

Foliar turnover rates in Finland — comparing estimates from needle-cohort and litterfall-biomass methods

201