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2. Annual net nitrogen mineralization and litter flux in well-drained downy birch, Norway spruce and Scots pine forest ecosystems

Author

Becker, Hardo, Aosaar, Jürgen, Varik, Mats, Morozov, Gunnar, Aun, Kristiina, Mander, Ülo, Soosaar, Kaido, and Uri, Veiko

Subjects
Forestry, SD1-669.5
Abstract

The main aim of the current study was to estimate the annual net nitrogen mineralization (NNM) flux in stands of different tree species growing on drained peatlands, as well as to clarify the effect of tree species, soil properties and litter on annual NNM dynamics. Three study sites were set up in May 2014: a downy birch ( Ehrh.) stand and a Norway spruce ( (L.) Karst.) stand in full-drained swamp (ODS) and a Scots pine ( L.) stand in full-drained swamp (MDS). The NNM flux was estimated using the method with incubated polyethylene bags. The highest value of NNM was found in stands that were growing on fertile ODS: 127.5 kg N ha yr and 87.7 kg N ha yr, in the downy birch stand and in the Norway spruce stand, respectively. A significantly lower annual NNM flux (11.8 kg N ha yr) occurred in the Scots pine stand growing in MDS. Nitrification was highest at fertile ODS sites and ammonification was the highest at the low fertility MDS site. For all study sites, positive correlation was found between soil temperature and NNM intensity. The difference in annual NNM between the downy birch stand and the Norway spruce stand growing on similar drained fertile peatlands was due to litter quality. The annual N input into the soil through leaf litter was the highest at the downy birch site where also the C/N ratio of litter was the lowest. The second highest N input into the soil was found in the spruce stand and the lowest in the pine stand.Betula pubescensPicea abiesOxalisPinus sylvestrisMyrtillusin situâ1â1â1â1â1â1

Published
2018
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3. Hariliku kuuse (Picea abies (L.) H. Karst.) kändude juurimise tootlikkus juurimisagregaadiga Pallari KH-160 neljal Eesti katsealal

Author

Kurvits Vahur, Muiste Peeter, Padari Allar, and Uri Veiko

Subjects
pallari kh-160, stump lifting, norway spruce, productivity, Forestry, SD1-669.5
Abstract

The aim of this paper was to provide an overview of the productivity of the stump lifting device Pallari KH-160, the distribution of working time, and to assess the dependence of the time and productivity of lifting operations on stump diameter in four different sample areas. Viru and Orguse sample areas were located in the Hepatica site type, Elva sample area in the Oxalis site type, and Rõuge test area in the Myrtillus site type. Viru sample area had smaller stumps compared to the others and had more stumps affected by decay. The highest productivity in terms of dry mass or volume was observed in stump lifting in Rõuge sample area, where 9.8 t of stumps were lifted per hour based on dry mass. The productivity of Viru and Orguse sample areas was lower, but these sample areas are located in the Hepatica site type, characterized by limestone substrates and leached soils. In contrast, Elva and Rõuge test areas are in the Oxalis and Myrtillus site types, respectively, with soils that are predominantly sandy. As the diameter of the stumps increased, the time required per stump increased, but the lifting speed per unit mass also increased. In other words, the productivity of lifting in stands with larger stumps is higher than in stands with smaller stumps. For example, the average productivity of lifting 10 cm diameter stumps is 0.8 t/h, for 20 cm stumps it is 2.2 t/h, and for 60 cm stumps it is 11.8 t/h.

Published
2024
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5. Nutrient allocation, accumulation and above-ground biomass in grey alder and hybrid alder plantations

Author

Uri, Veiko, Tullus, Hardi, and Lõhmus, Krista

Subjects
Forestry, SD1-669.5
Abstract

The aim of the present work was to investigate the nutrient (N,P,K) allocation and accumulation in grey alder (Alnus incana (L.) Moench) and hybrid alder (Alnus incana (L.) Moench x Alnus glutinosa (L.) Gaertn.) plantations growing on former agricultural land and to estimate the above-ground biomass production during 4 years after establishment. In August of the 4th year, when leaf mass was at its maximum, the amount of nitrogen accumulated in above-ground biomass of grey alder stand was 142.0 kg haâ1, the amount of phosphorus 16.3 kg haâ1 and the amount of potassium 49.5 kg haâ1. The amount of nitrogen accumulated in a hybrid alder stand totalled 76.8 kg haâ1, that of phosphorus 6.2 kg haâ1 and that of potassium 28.2 kg haâ1. The smaller amounts of N,P and K bound in the hybrid alder plantation are related to the smaller biomass of the stand. Still, the amounts of N,P and K consumed for the production of one ton of biomass were similar in the case of up to 4-year-old grey alder and hybrid alder stands. In the 4th year, the amount of nutrients consumed in one ton of biomass produced were: 16.0 kg N, 1.6 kg P and 5.4 kg K for grey alder and 14.6 kg N, 1.1 kg P and 5.2 kg K for hybrid alder. In the 4th year the total above-ground biomass (dry mass) of grey alder (15750 plants haâ1) amounted to 12.3 t haâ1, current annual increment being 6.7 t haâ1. In hybrid alder stands (6700 plants haâ1), the respective figures were 6.1 t haâ1 and 4.5 t haâ1. Comparison of the production capacity on the basis of mean stem mass in the 4th year revealed that the stem mass of grey alder exceeded that of hybrid alder (0.64 kg and 0.58 kg, respectively). Grey alder outpaced hybrid alder in height growth; in the 4th year after establishment, the mean height of the grey alder stand was 4.6 ± 0.9 m and that of the hybrid alder plantation 3.5 ± 0.9 m.

Published
2003
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13. Reply to A. Lõhmus, 2022 letter to the editor regarding Uri et al. (2022): The dynamics of the carbon storage and fluxes in Scots pine (Pinus sylvestris) chronosequence

Author

Uri, Veiko, primary, Kukumägi, Mai, additional, Aosaar, Jürgen, additional, Varik, Mats, additional, Becker, Hardo, additional, Aun, Kristiina, additional, Lõhmus, Krista, additional, Soosaar, Kaido, additional, Uri, Marek, additional, Buht, Mikko, additional, Sepaste, Agnes, additional, and Padari, Allar, additional

Published
2022
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14. Litterfall dynamics in Scots pine (Pinus sylvestris), Norway spruce (Picea abies) and birch (Betula) stands in Estonia

Author

Uri, Veiko, primary, Kukumägi, Mai, additional, Aosaar, Jürgen, additional, Varik, Mats, additional, Becker, Hardo, additional, Aun, Kristiina, additional, Nikopensius, Maris, additional, Uri, Marek, additional, Buht, Mikko, additional, Sepaste, Agnes, additional, Padari, Allar, additional, Asi, Endla, additional, Sims, Allan, additional, and Karoles, Kalle, additional

Published
2022
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29. The effect of stump harvesting on tree growth and the infection of root rot in young Norway spruce stands in hemiboreal Estonia

Author

Aosaar, Jürgen, primary, Drenkhan, Tiia, additional, Adamson, Kalev, additional, Aun, Kristiina, additional, Becker, Hardo, additional, Buht, Mikko, additional, Drenkhan, Rein, additional, Fjodorov, Merit, additional, Jürimaa, Katrin, additional, Morozov, Gunnar, additional, Pihlak, Laura, additional, Piiskop, Kätlin, additional, Riit, Taavi, additional, Varik, Mats, additional, Väär, Rait, additional, Uri, Marek, additional, and Uri, Veiko, additional

Published
2020
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33. The carbon balance of a six-year-old Scots pine (Pinus sylvestris L.) ecosystem estimated by different methods

Author

Uri, Veiko, primary, Kukumägi, Mai, additional, Aosaar, Jürgen, additional, Varik, Mats, additional, Becker, Hardo, additional, Aun, Kristiina, additional, Krasnova, Alisa, additional, Morozov, Gunnar, additional, Ostonen, Ivika, additional, Mander, Ülo, additional, Lõhmus, Krista, additional, Rosenvald, Katrin, additional, Kriiska, Kaie, additional, and Soosaar, Kaido, additional

Published
2019
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37. Adaptive root foraging strategies along a boreal–temperate forest gradient

Author

Ostonen, Ivika, primary, Truu, Marika, additional, Helmisaari, Heljä‐Sisko, additional, Lukac, Martin, additional, Borken, Werner, additional, Vanguelova, Elena, additional, Godbold, Douglas L., additional, Lõhmus, Krista, additional, Zang, Ulrich, additional, Tedersoo, Leho, additional, Preem, Jens‐Konrad, additional, Rosenvald, Katrin, additional, Aosaar, Jürgen, additional, Armolaitis, Kęstutis, additional, Frey, Jane, additional, Kabral, Naima, additional, Kukumägi, Mai, additional, Leppälammi‐Kujansuu, Jaana, additional, Lindroos, Antti‐Jussi, additional, Merilä, Päivi, additional, Napa, Ülle, additional, Nöjd, Pekka, additional, Parts, Kaarin, additional, Uri, Veiko, additional, Varik, Mats, additional, and Truu, Jaak, additional

Published
2017
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40. Long-term dynamics of leaf and root decomposition and nitrogen release in a grey alder (Alnus incana (L.) Moench) and silver birch (Betula pendula Roth.) stands.

Author

Morozov, Gunnar, Aosaar, Jürgen, Varik, Mats, Becker, Hardo, Lõhmus, Krista, Padari, Allar, Aun, Kristiina, and Uri, Veiko

Subjects
FOREST litter decomposition, EFFECT of nitrogen on plants, ALNUS incana, EUROPEAN white birch, PLANT roots, FOREST soils, LEAVES
Abstract

The decomposition of the leaf litter, fine roots (d < 2 mm) and coarser roots (2 ≤ d < 5 mm) of grey alder and silver birch, as well as of α-cellulose sheets using the litterbag method was studied in two experimental stands on Podzoluvisol soils in Southern Estonia. For both tree species, the coarser roots decomposed faster than the fine roots, (p < .05), tree species did not affect the decomposition rate of the roots (p > .5). The nitrogen (N) input to soil from aboveground litter was multiple times higher than the N flux from roots. The remaining relative ash-free mass of the leaves of grey alder and silver birch after three and a half years was similar. After 11 years the remaining relative ash-free mass of the fine and coarser roots of grey alder still accounted for around 10% of the initial value. For silver birch the remaining value was around 20% after 9 years. The litterbag method to underestimates in fertile soils the decomposition of organic matter and thus did not reflect the actual dynamics of decomposition. [ABSTRACT FROM AUTHOR]

Published
2019
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44. Eesti hall-lepikud bioenergiaressursina : SA Keskkonnainvesteeringute Keskuse lepingu nr. 11-10-8/196 KIK metsanduse programmi 2010.a. projekt nr. 27 tulemuste kokkuvõte

Author

Uri, Veiko and Eesti Maaülikool. Metsandus- ja maaehitusinstituut

Subjects
kokkuvõtted, Eesti, hall-lepikud, puistud
Abstract

Järjest suurenev nõudlus energiapuidu järele muudab aktuaalsemaks kiirekasvuliste puude kasvatamise ja majandamise Eestis. Üheks kiirekasvulisemaks ning vastupidavamaks puuliigiks meie looduses on hall lepp (Alnus incana (L.) Moench) ning ta on perspektiivne puuliik ka lühikese raieringiga metsanduse (energiametsanduse) seisukohalt. Hetkel on Eestis kasvavate hall-lepikute tagavara 31 miljonit m3 (Aastaraamat Mets 2010) ja see ressurss on tugevalt alamajandatud. Kuid kahanev fossiilsete kütuste varu maailmas ja suurenev nõudlus bioenergia järele lubavad oletada, et lähitulevikus hakatakse Eestis hall-lepikuid senisest rohkem majandama. Biomassi, sealhulgas puidu kasutamine energia tootmiseks võimaldab oluliselt vähendada CO2 emissiooni ja seeläbi leevendada ka võimalikke kliimamuutusi. Euroopa Liit on seadnud aastaks 2020 energia sektorile eesmärgiks suurendada taastuvenergia kasutamist 20%-ni (Directive 2009/28/EC). Sellest tulenevalt võib lähitulevikus oodata intensiivsemat ja ulatuslikumat hall-lepikute majandamist, mis aga eeldab paremaid teadmisi nende puistute kasvukäigust, produktsioonivõimest, aga ka majandamise mõjust keskkonnale, eelkõige lämmastikuringele. Kuigi Eestis on uuritud hall-lepikute biomassi ja kasvudünaamikat viimasel kümnendil üsna intensiivselt (Uri et al. 2002, 2009, 2010), pärinevad esimesed ning seni ainukesed Eestis koostatud hall-lepikute kasvukäigutabelid aastast 1930 (Raukas 1930). Samas peaks metsade jätkusuutlik ning looduslähedane majandamine põhinema adekvaatsetel teadusuuringutel ning nende põhjal koostatud puistute kasvumudelitel. Käesolevas projektis on püütud katta mõningaid olulisi seni uurimata hall-lepikute kasvatamise ning majandamisega seotud aspekte Eestis.

Published
2011

45. Metsageneetiliste ressursside säilitamise strateegia ning metsakultiveerimismaterjali tootmise ja kasutamise strateegia lähteülesannete koostamine ning täiendavate vajakute kaardistamine : projekti lõpparuanne

Author

Maaten, Tiit (koostaja), Tetlov, Eda (konsultant), Laas, Eino (konsultant), Jõgiste, Kalev (konsultant), Eek, Liina (konsultant), Parv, Maret (konsultant), Külvik, Mart (konsultant), Bratka, Märt (konsultant), Siimon, Vahur (konsultant), Uri, Veiko (konsultant), and Eesti Maaülikool. Metsandus- ja maaehitusinstituut

Subjects
aruanded, metsakultiveerimine, looduskaitse, Eesti, metsad, geneetilised ressursid
Abstract

Projekti eesmärgiks oli eeltöö metsageneetiliste ressursside säilitamise ning metsa-kultiveerimismaterjali kasutamise ja tootmise strateegia koostamiseks. Projekti taotluse koostamise ja täitmise vahelisel ajal projekti eesmärk veidi muutus kuid sisu jäi sisuliselt samaks, samuti pöörati põhirõhk metsageneetiliste ressursside säilitamist reguleerivate õigusaktide loomiseks ja täiendamiseks vajalike põhjenduste ning ettepanekute väljatöötamisele.

Published
2011

48. Puittaimede kasutusvõimalused energiakultuurina Eestis

Author

Tullus, Hardi (koostaja), Tullus, Hardi, Koppel, Andres, Uri, Veiko, Tullus, Arvo, and Pärn, Linnar

Subjects
uuringute aruanded, puittaimed, Eesti, energiakultuurid
Abstract

Vastavalt Maaelu Edendamise Sihtasutuse ja Eesti Maaülikooli vahel sõlmitud töövõtulepingule uuring peab: 1) Andma võrdleva ülevaate Eestis viljelemiseks sobivatest ning soovituslikest energiakultuuride liikidest ja sortidest (sh geneetiliselt muundatud) vastavalt kasutuseesmärgile; 2) Analüüsima energiakulutuuride viljelemiseks vajaminevat tehnikat ja agrotehnoloogia olemasolu kohta ning täiendavast vajadusest või olemasoleva kohendamisvajadusest potentsiaalset tootmismahtu silmas pidades; 3) Analüüsima ja kirjeldama eri energiakultuuride viljelemise mõju mulla viljakusomadustele; 4) Andma hinnangu eri energiakultuuride sobivuse ja kasvatamise võimaluste kohta piirkonniti tulenevalt EL ühise põllumajanduspoliitika jõustuvatest ristvastavusnõuetest; 5) Analüüsima energiakultuuride kasvatamist piiravaid ja soodustavaid tegureid (sh keskkonnakaitselisi nõudeid); 6) Analüüsima oodatavaid keskkonnamõjusid; 7) Andma soovitused energiakultuuride laialdasema viljelemise korraldamiseks Eestis. Viiakse läbi varemkogutud erinevate puuliikide erinevate biomassifraktsioonide kalorsuse uuringud. Tulemuseks peab olema analüüs, mis annab ülevaate, milliseid kultuure konkreetsetes oludes on võimalik ja otstarbekas viljelda, milliseid keskkonnakaitselisi ja agrotehnoloogilisi nõudeid (sh ristvastavusnõudeid) tuleb viljelemisel arvestada, toob välja energiakultuuride kasvatamist piiravad ja soodustavad tegurid ning esitab vajadusel ettepanekud ametliku korralduse (õigusaktid, fiskaalinstrumendid jms) muutmiseks, et soodustada energiakultuuride viljelemist soovitataval määral.

Published
2007

49. The reclamation of the North Estonian oil shale mining area

Author

Lõhmus, Krista, primary, Kull, Ain, additional, Truu, Jaak, additional, Truu, Marika, additional, Kaar, Elmar, additional, Ostonen, Ivika, additional, Meel, Signe, additional, Kuznetsova, Tatjana, additional, Rosenvald, Katrin, additional, Uri, Veiko, additional, Kurvits, Vahur, additional, and Mander, Ülo, additional

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