Stubbrytningens klimatpåverkan : en studie av stubbrytningens kortsiktiga effekter på koldioxidbalansen i boreal barrskog

Harvesting stumps for biofuel purposes has the potential to reduce the amount of fossil fuel that we use. The climate gain from exchanging fossil- for biofuel can however be offset if the harvesting technique results in higher decomposition rates. Stump extraction causes a significant disturbance of the soil that could result in a net CO2 efflux from increased decomposition. The aim of this study was to determine whether or not stump harvesting can be considered climate neutral in terms of CO2 emissions in a short term perspective. To do this, NEE (net ecosystem exchange) for three years from two areas in a former coniferous boreal forest in central Sweden was investigated. The reference site was clear felled and site prepared, the control site was clear felled, stump harvested and then site prepared. For comparison, the reduced amount of decomposable substrate on the stump harvested site had to be accounted for. This was achieved by calculating the total amount of stump biomass that was removed and then by modelling respiration from its decay using a negative exponential function. The results indicate no increase in CO2 emissions from the stump harvested site, on the contrary it was found to be a smaller CO2 source annually than the reference site. The difference in CO2 fluxes was however not significant (p<0,05). In conclusion stump harvesting can be considered climate neutral in terms of CO2 emissions in a short term perspective. The long term effects of stump harvesting are however still unknown.Att skörda stubbar för att använda som biobränsle kan potentiellt minska användandet av fossila bränslen, men klimatnyttan reduceras om avverkningstekniken skulle visa sig resultera i en ökad nedbrytning. Stubbrytning orsakar en kraftig störning av jorden som skulle kunna leda till ökad nedbrytning och ett ökat koldioxidflöde från marken. Syftet med denna studie är att avgöra huruvida stubbskörd kan anses klimatneutralt i fråga om CO2-utsläpp ur ett kortsiktigt perspektiv. För jämförelsen undersöktes två ytors kolbalanser för tre år. Ytorna låg i en tidigare boreal barrskog i Mellansverige. Referensytan var slutavverkad och markberedd, kontrollytan var slutavverkad, stubbskördad och därefter markberedd. De två ytornas kolbalanser var dock inte direkt jämförbara eftersom stubbarna skördats från kontrollytan och mängden nedbrytbart substrat alltså minskat med en betydande mängd. Detta korrigerades genom att beräkna den totala mängden stubbiomassa som skördats för att sedan modellera nedbrytningen med en negativ exponentialfunktion. Den resulterande mängden koldioxid från nedbrytningen adderades till den stubbskördade ytans för analys. Studien visar inte på några signifikanta (p<0,05) skillnader i koldioxidflöden från stubbskördad mark jämfört med konventionellt slutavverkad mark. Tvärtom visade sig den stubbskördade ytan årligen vara en mindre kolkälla än referensytan under undersökningsperioden. Den störning som stubbrytning utgör verkar således inte vara mer omfattande än den som utgörs av markberedningsåtgärder. Sammanfattningsvis kan stubbrytning anses vara klimatneutralt i fråga om CO2-utsläpp ur ett kortsiktigt perspektiv. De långsiktiga effekterna av stubbskörd är dock fortfarande okända

Comparing weaning methods in dairy calves with different dam-contact levels

Allowing the dam to rear her calf is an alternative practice in the dairy industry where cow and calf may gain welfare benefits from performing natural and highly motivated behaviors. However, this system has been linked to an increased separation and weaning response. Reducing the daily dam-calf-contact time may be a way to prepare the calf for weaning and separation. The first aim of the present study was to investigate the effect of 8 weeks of half-day dam-calf-contact on calves' response to weaning and separation, compared with calves reared with whole-day dam-calf-contact and an artificially reared, group-housed control with unrestricted access to milk for 20 min twice daily. Weaning off milk and separation from the dam can be viewed as 2 independent stressors. By introducing each stressor separately, it may be possible to reduce the overall behavioral response. The second aim of the present study was to investigate the effect of one-week fence-line weaning before permanent separation. The study was conducted with a 3x2 factorial design with dam-contact treatments: “Whole-day,” “Half-day” and “Control” and weaning treatments “Simultaneous” and “Stepwise.” Whole-day calves were separated twice daily from their dams during milking while Half-day calves were separated daily from the afternoon milking and until next morning milking. Simultaneous weaning and separation were done in wk 9, while Stepwise weaning and separation started in wk 8 with calves being fence-line weaned before permanent separation in wk 9. Data were collected on 69 dairy calves in wk 8 and wk 9, and data were summarized over the 2 weeks for analysis. Stepwise weaning and separation reduced the number of high-pitched vocalizations and activity of dam-reared dairy calves, while having little impact on control calves. There was no difference between Whole-day and Half-day calves in their response to separation, but as expected, dam-reared calves reacted more strongly than the control group. This was also reflected in the average daily BW gain the week after weaning, with Control calves having a higher average daily gains than Whole-day, while Half-day calves were intermediate. However, the behavioral response did not fully wane within the observation period (0–48 h of interventions). In conclusion, one-week fence-line weaning reduced the summed weaning and separation response in dam-reared calves. However, no difference between half-day dam-calf contact and whole-day dam-contact was detected as regards the behavioral response to weaning and separation

Performing Rurality in Online Community Groups*

In this paper, we investigate how rurality is performed in online community groups, attending in particular to outdoor recreation and engagement with local nature. The starting point for our performative approach is that when places are digitally mediated, the technological intermediary is never innocent or neutral. Methodologically, we conducted an online ethnography in 20 rural community groups on Facebook during one full year, collecting every post and associated comment threads relating to outdoor recreation and other forms of engagement with local nature. An iterative, heuristic coding process was employed to engage with and further develop existing performative approaches to the sociological study of rural places. Distinguishing throughout between staged and quotidian performances, our findings detail how the routines, pleasures, and tasks of everyday rural life are performed online. Important distinctions that emerge from this include routines that are given vis-à-vis those that are in-the-making; pleasures based on impression and expression respectively; and tasks relating to carework and sharework. The paper contributes valuable new insights regarding the performance of rurality in the age of the everyday Internet.publishedVersio