CO2 production as a measure of decay activity in wood blocks

Allan Klingström

CO2 production as a measure of decay activity in wood blocks

Allan Klingström

Publikation: Bok/rapport/proceedings › Rapport › Forskning

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Sammanfattning

1. Yttersta splinten har hög CO2-produktion i nyavverkad frisk granved med temperaturoptimum slid + 38°-40°C. C02-avgivningen minskar in mot gränsen mellan splint och kärna. Kärnveden har ingen SO"-produktion. 2. CO2-avgivningen från kärnved med naturlig Fomes annosus-röta är låg och jämn vid mätning i anslutning till avverkning. Om klossar med naturlig röta fuktas något och får acklimatiseras några dygn vid + 25°C och hög relativ luftfuktighet, inträder stark ökning av CO2- avgivningen, och spridningen för CO2-värdena blir stor. Detta gäller oavsett man använder torrvikt eller totalkväve som referens for CO2. 3. CO2-avgivningen från naturligt anlagd rotröta är starkt temperaturberoende med optimum vid + 29°C. Lagring av ved vid låga temperaturer kan påverka CO2-avgivningens intensitet vid påföljande försök vid högre temperaturer. 4. Fuktkvoten i rotved påverkar CO2-avgivningen mindre entydigt inom vida gränser. Sub- och supraoptimala värden verkar dock hämmande. 5. Om substansförlust mätes vid upprepade tillfällen och befinnes ha en konstant hastighet pendlar också C02-värdena inom snäva gränser. Detta gäller naturligt anlagd rotröta. Man kan alltså fastställa C02-värden som motsvarar en viss intensitet av substansförlusten för den undersökta svampen. Olika svamparter och olika rottyper kan inte utan vidare jämföras. Vid rotförsök med sterila torrviktsbestämda träklossar kan initialskedet giva höga CO2-värden, som sedan sjunker. Detta återspeglas vanligen ej av substans-förlusten, som kan vara jämnt kontinuerlig. 6. C02-mätningar på röta i ved ger känsliga utslag för t. ex. förändringar av temperatur och fuktighet, införande av antagonistiska svampar eller tillförande av impregnerings-medel eller andra giftiga ämnen. Metoden bör kunna användas för studier av naturligt anlagda rotprocesser, då det är mycket besvärligt att uppskatta en torrvikt vid start av försök utan att drastiskt torka veden och därmed skada de svampar man vill studera.

Originalspråk	Engelska
Förlag	Skogshögskolan
Antal sidor	20
Status	Publicerad - 1965
Externt publicerad	Ja

Publikationsserier

Serie	Studia Forestalia Suecica
Numrering	26
ISSN	0039-3150

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@book{19fca6f304d842719e1efe3e2ef616cf,

title = "CO2 production as a measure of decay activity in wood blocks",

abstract = "1. There is a high CO2 production in the youngest sapwood of newly felled, sound spruce with an optimum temperature of + 38-40°C. The CO2 output diminishes towards the boundary between sapwood and heartwood. The heartwood has no CO2 production. 2. The CO2 output of heartwood with naturally established decay of Fomes annosus is low and even when measured directly after felling. If blocks with natural decay are moistened slightly and permitted to acclimatise for some days at 125°C in a high relative air humidity a sharp increase in the CO2 output ensues. The variation in CO2 output among replicates becomes high irrespective of whether dry weight or N-content is used as a reference for CO2 output. 3. The CO2 output of naturally occurring root rot varies to a great extent with changes in temperature; the optinlurn temperature is + 2g°C. The storage of wood in low temperatures may affect the intensity of the CO2 output in later experiments at higher temperatures. 4. The moisture quotient in decaying wood affects the CO2 output less clearly between wide limits. Sub-optimum and super-optimum temperatures have a restricting effect however. 5. If the weight loss is measured frequently and found to have a constant rate the CO2 values also move between close boundaries. This concerns naturally established decay. It is therefore possible to establish CO2 values quite accurately. In other words one can determine CO2 values which correspond to a certain intensity of weight loss in the fungus under examination. In decay tests using sterile wood blocks of known dry weight high CO2 values can be recorded in the initial phase, which then decrease. This is not reflected by the weight loss, which can have a constant rate in ordinary experiments. 6. CO2 measurements in decaying wood are highly sensitive for example to changes in temperature and moisture, inoculation with antagonistic fungi or the introduction of preservatives or other poisonous substances. It should be possible to use the method for the study of natural decay processes as it is very difficult to estimate the dry weight at the start of the test without drastically drying the wood, thereby damaging the fungi it is proposed to study.",

author = "Allan Klingstr{\"o}m",

year = "1965",

language = "English",

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N2 - 1. There is a high CO2 production in the youngest sapwood of newly felled, sound spruce with an optimum temperature of + 38-40°C. The CO2 output diminishes towards the boundary between sapwood and heartwood. The heartwood has no CO2 production. 2. The CO2 output of heartwood with naturally established decay of Fomes annosus is low and even when measured directly after felling. If blocks with natural decay are moistened slightly and permitted to acclimatise for some days at 125°C in a high relative air humidity a sharp increase in the CO2 output ensues. The variation in CO2 output among replicates becomes high irrespective of whether dry weight or N-content is used as a reference for CO2 output. 3. The CO2 output of naturally occurring root rot varies to a great extent with changes in temperature; the optinlurn temperature is + 2g°C. The storage of wood in low temperatures may affect the intensity of the CO2 output in later experiments at higher temperatures. 4. The moisture quotient in decaying wood affects the CO2 output less clearly between wide limits. Sub-optimum and super-optimum temperatures have a restricting effect however. 5. If the weight loss is measured frequently and found to have a constant rate the CO2 values also move between close boundaries. This concerns naturally established decay. It is therefore possible to establish CO2 values quite accurately. In other words one can determine CO2 values which correspond to a certain intensity of weight loss in the fungus under examination. In decay tests using sterile wood blocks of known dry weight high CO2 values can be recorded in the initial phase, which then decrease. This is not reflected by the weight loss, which can have a constant rate in ordinary experiments. 6. CO2 measurements in decaying wood are highly sensitive for example to changes in temperature and moisture, inoculation with antagonistic fungi or the introduction of preservatives or other poisonous substances. It should be possible to use the method for the study of natural decay processes as it is very difficult to estimate the dry weight at the start of the test without drastically drying the wood, thereby damaging the fungi it is proposed to study.

AB - 1. There is a high CO2 production in the youngest sapwood of newly felled, sound spruce with an optimum temperature of + 38-40°C. The CO2 output diminishes towards the boundary between sapwood and heartwood. The heartwood has no CO2 production. 2. The CO2 output of heartwood with naturally established decay of Fomes annosus is low and even when measured directly after felling. If blocks with natural decay are moistened slightly and permitted to acclimatise for some days at 125°C in a high relative air humidity a sharp increase in the CO2 output ensues. The variation in CO2 output among replicates becomes high irrespective of whether dry weight or N-content is used as a reference for CO2 output. 3. The CO2 output of naturally occurring root rot varies to a great extent with changes in temperature; the optinlurn temperature is + 2g°C. The storage of wood in low temperatures may affect the intensity of the CO2 output in later experiments at higher temperatures. 4. The moisture quotient in decaying wood affects the CO2 output less clearly between wide limits. Sub-optimum and super-optimum temperatures have a restricting effect however. 5. If the weight loss is measured frequently and found to have a constant rate the CO2 values also move between close boundaries. This concerns naturally established decay. It is therefore possible to establish CO2 values quite accurately. In other words one can determine CO2 values which correspond to a certain intensity of weight loss in the fungus under examination. In decay tests using sterile wood blocks of known dry weight high CO2 values can be recorded in the initial phase, which then decrease. This is not reflected by the weight loss, which can have a constant rate in ordinary experiments. 6. CO2 measurements in decaying wood are highly sensitive for example to changes in temperature and moisture, inoculation with antagonistic fungi or the introduction of preservatives or other poisonous substances. It should be possible to use the method for the study of natural decay processes as it is very difficult to estimate the dry weight at the start of the test without drastically drying the wood, thereby damaging the fungi it is proposed to study.

UR - https://res.slu.se/id/publ/125317

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BT - CO2 production as a measure of decay activity in wood blocks

PB - Skogshögskolan

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