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Dominant fungi, especially primary decayers, probably influence other fungi growing together with them. Fomitopsis pinicola is one of the important primary decayers, and it has been shown that several other species regularly co-occur together with it. We asked whether the presence of common species (especially F. pinicola) affects the species richness and composition of other fungi. This study was conducted in an old-growth mountain spruce forest in the Bohemian Forest, Czech Republic. We surveyed logs on the ground for sporocarps of fungi in three successive years. Characteristics of logs such as dimensions, stage of decay and the cause of tree death (wind, competition, butt rot, bark beetles and unascertained) were recorded. F. pinicola was abundant mostly on logs that originated from trees infested by bark beetles. Analysis of covariance with the volume of logs and decay stage as covariables showed significant effect of these covariables and of F. pinicola presence on species numbers – logs in middle decay stages with the sporocarps of F. pinicola had more species than other logs. Based on Canonical Correspondence Analysis with volume, decay stage and the cause of tree death as covariables, the species composition on logs was also influenced by F. pinicola. We found such statistical effects in several other species. Redlisted species Antrodiella citrinella and Camarops tubulina co-occurred with F. pinicola.
I tested the hypothesis that habitat heterogeneity increases with increasing amounts of coarse woody debris (CWD) by comparing Peromyscus maniculatus populations in sites with high and low amounts of CWD. Sherman live-trapping technique was applied to monitor population fluctuation and to measure demographic parameters. In sites with high amount of CWD density was higher, populations fluctuated less, survivorship was better and residency time was longer. These results were in accordance with predictions of habitat heterogeneity and CWD played an important role for demography of P. maniculatus in managed coniferous forests.
Seasonal fluctuation and its causes for three species of Sorex shrews and the shrew-mole Neurotrichus gibbsii Baird, 1857 were investigated in three sites with high amounts of coarse woody debris (CWD) and three sites with low amounts of CWD in managed forests of western Washington, USA. Sorex trowbridgii Baird, 1857 was more abundant on sites with high amounts of CWD (captures per 100 trapping nights), and had higher reproductive rates than in sites with low amounts of CWD. Sorex monticolus Merriam, 1890 showed higher reproductive rates on sites with high amount of CWD. Population of Sorex vagrans Baird, 1857 fluctuated greater and abundance was higher in sites with low amounts of CWD. Most reproduction occurred from January to April and declined rapidly in May. Previous studies also have shown an early onset of breeding in Coastal California and Oregon. It seems that local species of soricids and Neurotrichus gibbsii gain reproductive benefits by breeding primarily in January through May.
Highly decayed coarse woody debris (CWD) is an important seedbed substrate in various forest ecosystems. In Europe, this particularly holds for spruce forests on shallow soils with insufficient water-holding capacity. Effect of Norway spruce (Picea abies L. Karst.) seedlings cover on CWD moisture was investigated under field conditions. Our hypothesis was that if CWD provides moisture benefits for successful recruitment and further growth of spruce seedlings, CWD water content should be considerably reduced in nurse logs compared to logs without spruce seedlings. The study was conducted in a natural subalpine Norway spruce forest located in the massif of Poľana (1351 m a.s.l.), Western Carpathians, Slovakia. Six downed spruce logs in advanced stage of decay were selected in the forest, three of them covered with advanced seedlings and the remaining logs devoid of them. CWD moisture was measured by Time Domain Reflectometry during two vegetation periods (2007, 2008). Average difference between CWD moisture in logs with and without advanced seedlings was –0.09 and thus significant at P = 0.02 according to t-test. Based on the tested assumption that throughfall was comparable for both groups of logs, the assessed evaporation of the seedlings cover reached ca 0.73 mm day⁻¹ m⁻² of CWD surface (in the horizontal projection) during one vegetation period. This rate is generally comparable with seedlings growing in soils under unconstrained moisture conditions. The role of nurse logs in the recruitment of spruce seedlings is therefore mainly important on soils with limited water-holding capacity.
Using the characteristic of accumulated woody debris, data on vegetation, and data on previous climate fluctuations, we reconstructed the history of Scots pine (Pinus sylvestris L.) encroachment and retreat in a raised bog. The available patchy information on plant cover allowed us to pinpoint events in the development of pine seedlings and the first cases of trees dying off on the time scale. The results obtained show that the process of natural bog afforestation and deforestation was very dynamic and lasted only 22 years. These short-term changes in the tree populations were clearly linked to short-term climate fluctuations. The annual precipitation and mean temperature of winter months were the most important variables and the main factors directly influencing the young woodland. We assumed that the woody remnants represent the last stage of the contemporary phase of high germination and dying-off (GDO) of pine trees. The spatial distribution of woody debris and its characteristics indicate the naturalness of vegetation during this temporary ‘woodland phase’. The study show that the investigation of woody debris can be used to further improve our understanding of bog vegetation dynamics, especially with regard to the influence of periodical climate fluctuations on transitions between open and forested peatland.
Background. Thirty species were previously recorded for unstructured habitats (unvegetated soft substrates: USS) in Pantanos de Centla. However, a lack of information on the tropical ichthyofauna of the structured habitats such as marginal vegetation (MV), submerged macrophytes (SM) and coarse woody debris (CWD) emphasizes the importance of the aim of this paper that is the updating the records of the species distributed in these habitats, as they have been frequently reported as high biodiversity sites that are currently threatened by anthropogenic activities. Materials and methods. Sampling was carried out in 30 shallow sites, each with unstructured habitats and the three structured habitats, in Pantanos de Centla, a Ramsar wetland, over a period of three years. Fish were collected with a dip net, a drop net and a Renfro beam net. Results. A total of 6506 fish of 37 genera and 44 species were collected. Eleven species are new records for Pantanos de Centla, and the scientific name of 11 species was updated. The Poeciliidae and Cichlidae families are dominant with 10 and 13 species, respectively. Nine species of the genus Cichlasoma sensu lato were placed in six genera. Three species are new records for the Usumacinta Province. Ctenogobius claytoni, Gobionellus oceanicus, and Rhamdia quelen proved to be synonyms. Of all species, 84% were collected from USS, however, the number of species distributed in USS, MV, and SM was similar (CCj 0.4736-0.5813). Conclusion. Most of the species that were added to the previously recorded species list of Pantanos de Centla, inhabit structured habitats. This confirms the importance of including these habitats in surveys aimed at generating checklists, and of analysing the distribution of fish species in shallow tropical ecosystems.
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