| 1. |
- Carlsson, Fredrik, et al.
(författare)
-
Effect of heat on interspecific competition in saprotrophic wood fungi
- 2014
-
Ingår i: Fungal ecology. - : Elsevier BV. - 1754-5048 .- 1878-0083. ; 11, s. 100-106
-
Tidskriftsartikel (refereegranskat)abstract
- Some boreal wood fungi that are associated with forest fire or open dry habitats have an increased resistance to heat in comparison to species associated with a less specific distribution or species found in mesic forests. We hypothesize that extreme temperature-stress experienced during fires will favor species adapted to heat and, ultimately, the composition of species inhabiting logs in such habitats will change. Competitiveness after temperature stress was examined in three fire-associated species – Dichomitus squalens, Gloeophyllum sepiarium and Phlebiopsis gigantea – and three non fire-associated species – Ischnoderma benzoinum, Phellinus pini and Fomitopsis pinicola. There was a difference between the fire-associated species and the non fire-associated species with respect to competitive strength after heat stress. All fire-associated species had an advantage after heat treatment, colonizing a larger volume of wood than any non-fire-associated competitor. Our findings suggest that increased heat tolerance of mycelia can exert a competitive balance shift after forest fire. It shows that a system governed by forest fire will be dominance controlled under certain conditions. Furthermore, from a management perspective, during a prescribed burning, certain species already present in the ecosystem will be favored if the fire is not allowed to totally consume the substrates.
|
|
| 2. |
- Carlsson, Fredrik, 1974-, et al.
(författare)
-
Increased CO2 evolution caused by heat treatment in wood-decaying fungi
- 2017
-
Ingår i: Mycological progress. - : Springer Science and Business Media LLC. - 1617-416X .- 1861-8952. ; 16:5, s. 513-519
-
Tidskriftsartikel (refereegranskat)abstract
- Wood-decaying fungi are regarded as the main decomposers of woody debris in boreal forests. Given that fungal respiration makes a significant contribution to terrestrial carbon flows, it is important to understand how the wood-decaying fungal metabolism is regulated in relation to different environmental conditions and disturbances. In the present study, we investigated the effect of temperature stress on wood decomposition rate in 18 species of wood-decaying fungi, representing a broad range of species-habitat associations. Heat shock duration and temperature were calibrated to match the conditions of a forest fire. We found a general increase in fungal decay rate after heat shock; the response was more pronounced in species associated with fire-prone forests. The underlying mechanism is unclear, but possibly relates to an up-regulation at the cellular level in response to heat shock. Our results show that the decomposition rate of dead wood can be strongly affected by environmental triggers.
|
|
| 3. |
- Carlsson, Fredrik, 1974-, et al.
(författare)
-
Increased decomposition, triggered by heat shock found in wood fungi
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Wood fungi can be extremely heat resilient: several studies have shown that species can survive highly elevated temperatures relative to their growth optima. In this study we examine the effect of heat shock on subsequent decomposition rates. Sixteen species of wood fungi were tested over a period of 17 weeks. All strains were inoculated on to sterilized pine wood cylinders, placed in small bio chambers and tested twiice a week for CO2 accumulation. After 8 weeks all species were subjected to heat shock. We found that this triggered an increased decomposition rate in all species, this increase peaked 6 weeks after the shock. the peak was higher in wood fungi species that are associated with forest fires compared to specoes with no such association.
|
|
| 4. |
- Carlsson, Fredrik, 1974-, et al.
(författare)
-
Increased heat resistance in mycelia from wood fungi prevalent in forests characterized by fire : a possible adaptation to forest fire.
- 2012
-
Ingår i: Fungal Biology. - : Elsevier BV. - 1878-6146 .- 1878-6162. ; 116:10, s. 1025-1031
-
Tidskriftsartikel (refereegranskat)abstract
- AbstractForest fire has for a long time been the major stand replacing/modifying disturbance in boreal forests. For organisms to adopt to this phenomenon different strategies for protective measurements has evolved. This study focuses on the organism group of wood fungi, and one of several possibilities for adaptation to forest fire - increased heat resistance in the mycelia. 16 species of wood fungi where selected and sorted a priori according to their prevalence for fire affected substrate. These were isolated and re-inoculated on pine wood before testing. Experiments where done in a series where the mycelia was exposed to 100, 140, 180, 220°C for 5, 10, 15, 20, 15 min. A very clear difference was found, the group containing species with a prevalence for a fire affected substrate had a much higher survival rate over all combinations of time and temperature compared to species with a more general ecology. This data suggests that increased heat resistance in mycelia could be a possible adaptation to forest fire. This in turn has major impacts on the ecology and population dynamics of wood fungi. An increase in temperature could shift the population structure in a log, allowing minor non fruiting mycelia content to expand on the expense of earlier dominant colonizers. Furthermore this study has implications on how to control prescribed restoration burning events. When burning areas where the dead wood content is dominated by early decay stages, loss of species can be avoided by proper management.
|
|
| 5. |
- Carlsson, Fredrik, 1974-
(författare)
-
Wood Fungi and Forest Fire
- 2014
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Forest fires have been the major stand-replacing/modifying disturbance in boreal forests. To adapt to fire disturbance, different strategies have evolved. This thesis focuses on wood fungi, and the effect of forest fire on this organism group. In many ways it is a study on adaptation to forest fire, in concurrence with adaptation to dry open habitats. In Paper I we study increased heat resistance in mycelia from species prevalent in fire prone environments. Fungi were cultivated on fresh wood and exposed to different temperatures. Species prevalent in fire affected habitats had a much higher survival rate over all combinations of time and temperature compared to species associated with other environments. Based on this results the competitiveness was tested after temperature stress (paper II), three fire associated species, were tested against three non fire associated species. All fire associated species had a clear advantage after heat treatment, conquering a larger volume of wood than its competitor. In paper III we studied the effect of heat shock on decomposition rate, 18 species was tested. Species were cultivated and monitored for CO2 accumulation for 8 weeks and then heat shocked. All species including non fire associated species seemed to up-regulate decomposition after heat shock, this response was more pronounced in fire associated species. To look at the possible effect of forest fire on population structure (Paper IV), we developed 29 SNP/INDELs for Phlebiopsis. gigantea. We amplified the marker containing fragments in 132 individuals of P. gigantea in 6 populations, 3 which were found in areas affected by forest fire and 3 in unaffected areas. We found no genetic structure in accordance to forest fire. However we detected geographic structure, which stands in contrast to earlier studies. This might be due to the method, using SNP´s and number of individuals in the study. Finally we collected cross-sections of decayed logs to evaluate the number of fungal species domains that are likely to be hit when drilling a saw-dust sample in a log. We used these estimates to simulate how many species that will be found by a certain number of samples. We found that in 99% of the
|
|
| 6. |
|
|
| 7. |
- Edman, Mattias, et al.
(författare)
-
Fungi and wind strongly influence the temporal availability of logs in an old-growth spruce forest
- 2007
-
Ingår i: Ecological Applications. - : Wiley. - 1051-0761 .- 1939-5582. ; 17:2, s. 482-490
-
Tidskriftsartikel (refereegranskat)abstract
- Coarse woody debris (CWD) is a key habitat for many species in forest ecosystems. To ensure the long-term survival of such species, forest management regimes must include measures that promote dead wood dynamics similar to those of natural forests. Thus, information on CWD dynamics under natural conditions is required, including data pertaining to the underlying agents of disturbance. This study examines modes of mortality, decay rates, and temporal patterns in the availability of Picea abies logs in a Swedish old-growth forest affected by internal, small-scale disturbance. All 684 logs in a 6.6-ha plot were mapped and classified into one of six decay classes. Logs in the early stages of decay were examined for the presence of heart-rot fungi. Six years later all logs were re-inventoried, including newly formed logs. Matrix models based on the transition rates between decay classes showed that it took about 60 years for 90% of the logs to decay beyond class 6 (a deformed trunk with soft wood). Large logs (≥26 cm) decayed 40% more slowly than small logs (≤25 cm). The initial volume of logs was 37.6 m3/ha but increased to 44.8 m 3/ha after six years. In addition, there was a large shift in the decay-class distribution. The volume of logs in early and late decay classes increased by 71% and 45%, respectively, while the volume of logs in the intermediate decay classes decreased by 32%. The fluctuations appear to result from pulses in mortality, driven by a combination of strong winds and the heart-rot fungus, Phellinus chrysoloma, which was present in more than 30% of all logs at an early stage of decay. These results show that large temporal fluctuations in dead wood also occur in the absence of large-scale disturbance, and that heart-rot fungi are important factors driving the overall dynamics of dead wood. Since many wood-inhabiting species are naturally rare and have very specific substrate demands, such temporal variability in dead wood availability may have effects on biodiversity and should be taken into account when designing small, protected forest areas.
|
|
| 8. |
- Edman, Mattias, et al.
(författare)
-
Local dispersal sources strongly affect colonization patterns of wood-decaying fungi on experimental spruce logs
- 2004
-
Ingår i: Ecological Applications. - : Wiley. - 1051-0761 .- 1939-5582. ; 14:3, s. 893-901
-
Tidskriftsartikel (refereegranskat)abstract
- Coarse woody debris (CWD) is an important habitat for many species in forest ecosystems. However, forestry has decreased the abundance of CWD so that many wood-dependent species have become threatened. To alleviate this problem, guidelines for a more biodiversity-oriented forestry focus on increasing CWD in managed forests. Unfortunately, how this increase is to be allocated on a landscape scale is not well understood. The present study reports an experiment in which freshly cut logs of varying sizes were placed in stands with contrasting abundance of natural CWD and subsequently varying pools of wood-inhabiting species. The first six years of colonization by wood fungi show that local abundance and composition of the fungal flora strongly influenced colonization. Higher species richness was observed in CWD-rich sites, and several species were more frequent on the experimental logs at CWD-rich sites. The strong within-site effect is interpreted as resulting from high spore deposition from the local species pool. This is supported by spore deposition estimates of Fomitopsis rosea, a red-listed species that only occurred on experimental logs at the CWD-rich sites. F. rosea had a 9-180 times higher spore deposition at the CWD-rich sites compared to the CWD-poor sites. The species richness and composition on small logs differed from that of large logs with higher richness on the latter. The results strongly suggest that restoration efforts would be more efficient if directed toward sites close to CWD-rich sites and that preferably large logs should be created.
|
|
| 9. |
|
|
| 10. |
- Edman, Mattias, et al.
(författare)
-
Spatial pattern of downed logs and wood-living fungi in an old-growth spruce forest
- 2001
-
Ingår i: Journal of Vegetation Science. - 1100-9233 .- 1654-1103. ; 12:5, s. 609-620
-
Tidskriftsartikel (refereegranskat)abstract
- Since many wood-living forest species are influenced by the dynamics of coarse woody debris (CWD), information about the spatial pattern of CWD under natural conditions is essential to understand species distributions. In this study we examined the spatial pattern of downed logs and wood-decaying fungi in an old-growth boreal Picea abies forest in northwestern Sweden that is governed by gap-phase dynamics. The spatial pattern of wood-decaying fungi was studied to draw conclusions about species dispersal abilities. A total of 684 logs with a diameter 10 cm were mapped and analysed with Ripley's K-function. The distribution of all logs taken together displayed a significant aggregated pattern up to 45 m. The different decay stages also deviated from random expectations. Fairly fresh logs and logs in the middle decay stage were clumped up to about 25 and 35 m respectively, and late decayed logs aggregated up to 95 m. Logs with diameters from 10-29 cm were aggregated up to 25 m, whereas logs ≥30 cm diameter were randomly distributed. The result suggests that gap-dynamics do have an impact on the spatial pattern of the CWD, creating fine-scale clumping. The random distribution of large logs may result from the slightly regular spacing of large living trees. The spatial patterns of 16 species (n 20) of wood-decaying fungi were analysed with Ripley's K-function. Three patterns were aggregated, for Gloeophyllum sepiarium, Coniophora olivacea and Vesiculomyces citrinus. These results indicate that the distribution of most species at the stand level is generally not influenced by dispersal limitations.
|
|
