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Nutrient imbalance in Norway spruce

Thelin, Gunnar LU (2000)
Abstract (Swedish)
Popular Abstract in Swedish

Studierna som presenteras i min avhandling visar att granmonokultur inte är uthålligt skogsbruk i en miljö med högt nedfall av kväve och svavel, som i södra Sverige. Markens näringskapital minskar p g a onaturligt hög tillväxt, orsakad av den höga kvävetillgången, och utlakning p g a markförsurning. När den begränsade tillgången på näring inte motsvarar trädens näringsbehov, ökar risken för näringsobalans.



I skånska gran- och tallbestånd har näringsstatus, hos såväl barr som mark, försämrats gradvis från mitten av 80-talet och framåt. Utvecklingen av näringsobalans verkar i stor utsträckning bero på högt nedfall av kväve och svavel. Idag begränsas tillväxt och vitalitet av... (More)
Popular Abstract in Swedish

Studierna som presenteras i min avhandling visar att granmonokultur inte är uthålligt skogsbruk i en miljö med högt nedfall av kväve och svavel, som i södra Sverige. Markens näringskapital minskar p g a onaturligt hög tillväxt, orsakad av den höga kvävetillgången, och utlakning p g a markförsurning. När den begränsade tillgången på näring inte motsvarar trädens näringsbehov, ökar risken för näringsobalans.



I skånska gran- och tallbestånd har näringsstatus, hos såväl barr som mark, försämrats gradvis från mitten av 80-talet och framåt. Utvecklingen av näringsobalans verkar i stor utsträckning bero på högt nedfall av kväve och svavel. Idag begränsas tillväxt och vitalitet av kalium, snarare än kväve, i granbestånd äldre än 40 år. Yngre bestånd, å andra sidan, verkar kunna ta emot högt kvävenedfall utan negativa effekter på tillväxt och vitalitet. Granens vitalitet bedömdes med en s k grenutvecklingsmetod. När man studerar effekter av näringsstress på vitalitet är indikatorer som grenlängd och skottutvecklingshastighet lämpliga, eftersom de kan mäta effekter som ackumulerats i flera år.



Det är nödvändigt med motåtgärder för att skogsproduktionen på sikt ska kunna upprätthållas i södra Sverige. I två bestånd med mikronäringsbrist i Mellansverige ledde vitatilitetsgödsling till förbättrad barrnäringsstatus. I ett av bestånden, där gödslingsmedlet beståndsanpassats och spridits från helikopter, påverkades även trädens vitalitet positivt. Det är mycket troligt att beståndsanpassning av vitaliseringsmedel förbättrar möjligheterna till positiva effekter av vitalitetsgödsling.



I en undersökning av gran i blandning med bok, björk, eller ek jämfört med monokultur visade sig granens näringsstatus vara högre i blandbestånd än i monokultur. Behoven av näringstillförsel, för att kompensera för näringsförluster, är sannolikt lägre i blandbestånd med lövträd än i granmonokulturer.



Det är möjligt att motverka näringsobalans genom förändrad skogsskötsel och näringstillförsel. Men, på sikt måste kvävenedfallet minska, om skogsmarkens långsiktiga produktionsförmåga ska kunna upprätthållas i södra Sverige. (Less)
Abstract
The studies presented in my thesis indicate that growing Norway spruce in monoculture does not constitute sustainable forest management in a high N and S deposition environment, such as in southern Sweden. The combination of N-induced high growth rates and leaching due to soil acidification causes soil reserves of nutrients to decrease. This will increase the risk of nutrient imbalance within the trees when nutrient demands are not met.



The development of nutrient imbalance in Scania, southern Sweden, was shown as negative trends in needle and soil nutrient status from the mid-80s to the present in Norway spruce and Scots pine stands. This imbalance appears to be connected to high levels of N and S deposition. Clear... (More)
The studies presented in my thesis indicate that growing Norway spruce in monoculture does not constitute sustainable forest management in a high N and S deposition environment, such as in southern Sweden. The combination of N-induced high growth rates and leaching due to soil acidification causes soil reserves of nutrients to decrease. This will increase the risk of nutrient imbalance within the trees when nutrient demands are not met.



The development of nutrient imbalance in Scania, southern Sweden, was shown as negative trends in needle and soil nutrient status from the mid-80s to the present in Norway spruce and Scots pine stands. This imbalance appears to be connected to high levels of N and S deposition. Clear negative effects on tree vitality were found when using a new branch development method. Today, growth and vitality seems to be limited by K, rather than N, in spruce stands older than 40 years. However, younger stands appear to be able to absorb the deposited N without negative effects on growth and vitality. When investigating effects of nutrient stress on tree vitality, indicators such as branch length and shoot multiplication rate, which include effects accumulated over several years, are suitable.



Countermeasures are needed in order maintain the forest production at a high level. Positive effects on tree nutrient status after vitality fertilization (N-free fertilization) was shown in two micronutrient deficient stands in south-central Sweden. In addition, tree vitality was positively affected after the application of a site-adapted fertilizer to the canopy. Site-adaption of fertilizers will most likely improve the possibilities of a positive response on tree growth and vitality in declining stands. In a survey of Norway spruce in mixtures with beech, birch, or oak compared to monocultures it was shown that spruce nutrient status was higher in mixtures with deciduous species than in monocultures. By using mixed-species stands the needs for nutrient additions are most likely decreased.



Nutrient imbalance may be counteracted by changed forest management and nutrient compensation. However, in the long term N deposition to the forest ecosystems must be decreased in order to maintain the productivity of the forest soils in southern Sweden. (Less)
Please use this url to cite or link to this publication:
author
opponent
  • Doctor Emmett, Bridget, Centre for Ecology and Hydrology, Bangor, UK
organization
publishing date
type
Thesis
publication status
published
subject
keywords
Silviculture, Växtekologi, Plant ecology, nitrogen saturation, base saturation, pH, multiple limitation, deficiency, copper, boron, potassium, pollution, sustainability, conifers, forestry, forestry technology, Skogsvetenskap, skogsbruk, skogsteknik, Soil Science, agricultural hydrology, Lantbrukshydrologi, marklära
pages
145 pages
publisher
Plant Ecology, Ecology Building, SE-223 62 Lund
defense location
Blå hallen, Ecology Building, Lund
defense date
2000-12-01 10:00
external identifiers
  • Other:ISRN: SE-LUNBDS/NBBE-00/1061+145pp
ISBN
91-7105-147-3
language
English
LU publication?
yes
id
0ba0a838-26b9-4771-a41f-d195336b8f5a (old id 41075)
date added to LUP
2007-08-01 09:30:30
date last changed
2016-09-19 08:45:04
@misc{0ba0a838-26b9-4771-a41f-d195336b8f5a,
  abstract     = {The studies presented in my thesis indicate that growing Norway spruce in monoculture does not constitute sustainable forest management in a high N and S deposition environment, such as in southern Sweden. The combination of N-induced high growth rates and leaching due to soil acidification causes soil reserves of nutrients to decrease. This will increase the risk of nutrient imbalance within the trees when nutrient demands are not met.<br/><br>
<br/><br>
The development of nutrient imbalance in Scania, southern Sweden, was shown as negative trends in needle and soil nutrient status from the mid-80s to the present in Norway spruce and Scots pine stands. This imbalance appears to be connected to high levels of N and S deposition. Clear negative effects on tree vitality were found when using a new branch development method. Today, growth and vitality seems to be limited by K, rather than N, in spruce stands older than 40 years. However, younger stands appear to be able to absorb the deposited N without negative effects on growth and vitality. When investigating effects of nutrient stress on tree vitality, indicators such as branch length and shoot multiplication rate, which include effects accumulated over several years, are suitable.<br/><br>
<br/><br>
Countermeasures are needed in order maintain the forest production at a high level. Positive effects on tree nutrient status after vitality fertilization (N-free fertilization) was shown in two micronutrient deficient stands in south-central Sweden. In addition, tree vitality was positively affected after the application of a site-adapted fertilizer to the canopy. Site-adaption of fertilizers will most likely improve the possibilities of a positive response on tree growth and vitality in declining stands. In a survey of Norway spruce in mixtures with beech, birch, or oak compared to monocultures it was shown that spruce nutrient status was higher in mixtures with deciduous species than in monocultures. By using mixed-species stands the needs for nutrient additions are most likely decreased.<br/><br>
<br/><br>
Nutrient imbalance may be counteracted by changed forest management and nutrient compensation. However, in the long term N deposition to the forest ecosystems must be decreased in order to maintain the productivity of the forest soils in southern Sweden.},
  author       = {Thelin, Gunnar},
  isbn         = {91-7105-147-3},
  keyword      = {Silviculture,Växtekologi,Plant ecology,nitrogen saturation,base saturation,pH,multiple limitation,deficiency,copper,boron,potassium,pollution,sustainability,conifers,forestry,forestry technology,Skogsvetenskap,skogsbruk,skogsteknik,Soil Science,agricultural hydrology,Lantbrukshydrologi,marklära},
  language     = {eng},
  pages        = {145},
  publisher    = {ARRAY(0xa986570)},
  title        = {Nutrient imbalance in Norway spruce},
  year         = {2000},
}