scholarly journals Wood-decaying fungi in old-growth boreal forest fragments: extinctions and colonizations over 20 years

Silva Fennica ◽  
2021 ◽  
Vol 55 (1) ◽  
Author(s):  
Atte Komonen ◽  
Ilkka Puumala ◽  
Gergely Varkonýi ◽  
Reijo Penttilä

According to ecology theory, isolated habitat fragments cannot maintain populations of specialized species. Yet, empirical evidence based on monitoring of the same fragments over time is still limited. We studied the colonization–extinction dynamics of eight wood-decaying fungal species in 16 old-growth forest fragments (<14 ha) over a 20-year period (1997–2017). We observed 19 extinctions and 5 colonizations; yet, the distribution of extinctions and colonizations did not differ from the one expected by chance for any of the species. Twenty-six percent of the extinctions took place in two natural fragments amid large forest–peatland complexes. (Romell) Bourdot and Galzin decreased and (P. Karst.) Bourdot increased in abundance (number of logs occupied). The volume of living spruce trees in the forest fragments correlated positively with the number of logs inhabited in five of the study species. Because fragment characteristics did not affect species turnover, it seems that stochastic processes governed colonizations and extinctions. Although the least abundant species in 1997 had declined, and the most abundant species had become more abundant, it appears that specialized wood-decaying fungi can persist for decades in isolated old-growth forest fragments, if suitable dead wood is continuously available.Phellinus nigrolimitatusPhellinus ferrugineofuscus

2019 ◽  
Vol 21 (1) ◽  
pp. 19-32 ◽  
Author(s):  
Ewa Durska ◽  
James Bonet ◽  
Bert Viklund

In natural forests, fire is an important disturbance factor and many studies have been carried out concerning its effect on different ecosystems, but no studies have previously been done considering the scuttle flies in hemiboreal forests. Here, we carried out an ecological investigation of the scuttle fly assemblage in a hemiboreal old-growth forest in Tyresta National Park and Nature Reserve (Sweden) from material collected, using Malaise traps, after wildfires in 1997 and 1999. We evaluated abundances of species, dominance structure, species richness (by non-parametric species richness method — Chao 1) as well as phenology. The most abundant species of the dominant group (i.e. Megaselia pleuralis, M. nigriceps, M pulicaria-complex and M. brevicostalis) are multivoltine and saprophagous, displaying spring and late summer/autumn activity.


2007 ◽  
Vol 139 (1) ◽  
pp. 118-130 ◽  
Author(s):  
Rebecca M. Zeran ◽  
Robert S. Anderson ◽  
Terry A. Wheeler

AbstractFungivorous Coleoptera were sampled from old-growth and managed (selectively logged in 1999) hemlock–hardwood forests in southeastern Ontario to examine the effect of small-scale forest management on fungivore diversity in forest fragments. Sampling using flight-intercept traps and trunk-window traps for 22 weeks in 2003 yielded 11 888 beetles representing 73 species in 11 target families (Anthribidae, Cerylonidae, Endomychidae, Erotylidae, Leiodidae, Mycetophagidae, Scaphidiidae, Sphindidae, Tenebrionidae, Trogossitidae, and Zopheridae). The leiodid subfamily Leiodinae was the dominant taxon (10 386 individuals, 38 species). While old-growth stands had no recent logging and had higher volumes of coarse woody debris, species diversity and composition of fungivorous Coleoptera were similar between forest types, suggesting that the stand differences measured (recent logging history, volume of coarse woody debris) did not have a significant effect on beetle diversity in this study. Indicator species analysis showed that Triplax macra LeConte (Erotylidae) was strongly associated with old-growth stands, while Anisotoma blanchardi (Horn), Anogdus obsoletus (Melsheimer), Agathidium sp. 1 (Leiodidae), and Mycetina perpulchra (Newman) (Endomychidae) were associated with managed stands. The lack of difference observed between stand types may be related to the small size of the forest fragments or the relatively small scale of the disturbance.


1990 ◽  
Vol 68 (5) ◽  
pp. 1156-1162 ◽  
Author(s):  
Cheryl A. Ingersoll ◽  
Mark V. Wilson

Soil blocks collected from an old-growth Pseudotsuga menziesii forest were subjected to three types of disturbances (shade removal, surface burning, and soil churning) in a factorial experiment. Most émergents (88%) were vegetative sprouts. Total emergence and emergence of vegetative sprouts were significantly higher in the undisturbed (control) treatment than in any other treatment. As intensity of disturbance (measured by the number of disturbance factors applied) increased, the number of emergents declined. Exposure to sun caused a significant decline in emergence of each of the six most abundant species; the effects of burning and churning varied by species. Burning decreased the emergence of species with shallow regenerating structures. None of the experimental treatments significantly affected seedling emergence. Density of émergents (both seedlings and vegetative sprouts) was higher under greenhouse condition (411.7/m2) than in the experimental treatments (94.6/m2), indicating that greenhouse emergence is more suitable for quantifying the buried propagule bank. Key words: seed bank, propagules, old-growth forest, disturbance, fire.


2003 ◽  
Vol 79 (3) ◽  
pp. 475-484 ◽  
Author(s):  
Andy MacKinnon

Canada's west coast, temperate, old-growth forests include its largest, most commercially valuable, fastest-growing, oldest, and certainly most fought-over forests. They can be divided into three main types: coastal rainforest, coastal subalpine forest, and "rain-shadow" forest. Although there is great variation within each of these broad types, coastal rainforests and subalpine forests share a wet climate and are relatively unimpacted by fire as a stand-replacing disturbance. This allows development of multi-aged, multi-canopy, old-growth forests with large volumes of living and dead wood. These forests are structurally and biologically complex. Coastal rain-shadow forests, on the other hand, have a distinctively drier climate (for the coast), and a history of frequent, low-intensity fires. Although well over half of Canada's original west coast, temperate, old-growth forests remain as old growth, there is great variation ecologically and geographically. In general, the percentage of old-growth forest remaining increases with increasing latitude and elevation. Key words: old growth, old-growth forest, coastal British Columbia, temperate rainforest, protected areas, stand structure


2020 ◽  
Vol 36 (3) ◽  
pp. 123-132
Author(s):  
Leila J.B. Gonçalves ◽  
Edgar E. Santo-Silva ◽  
Maria Fabíola Barros ◽  
Kátia F. Rito ◽  
Inara R. Leal ◽  
...  

AbstractThe proliferation of disturbance-adapted species in human-modified landscapes may change the structure of plant communities, but the response of biodiversity to human disturbances remains poorly understood. We examine the proliferation of the palm, Syagrus coronata, in disturbed forest stands and its impacts on the structure of vascular epiphyte assemblages in a human-modified landscape of Brazilian Caatinga dry forest. First, we compared S. coronata density between old-growth and regenerating forest stands. We then surveyed vascular epiphytes on 680 phorophytes (S. coronata and non-palm/control species) across five habitat types with different disturbance levels. There was an eight-fold increase in S. coronata density in regenerating areas compared with in old-growth forest. Syagrus coronota supported richer epiphyte assemblages at local (i.e. per palm) and landscape (i.e. pooling all palms) scale than control phorophytes, supporting more than 11 times the number of species of control phorophytes at both scales. Epiphyte assemblages were more abundant, species-rich and dominated by abiotically dispersed species in forest sites with intermediate disturbance levels (regenerating forest stands). More than simply operating as an exclusive phorophyte for more than 90% of the epiphyte species we recorded here, S. coronata favours epiphyte persistence and structures their assemblages across human-modified landscapes of the Caatinga forest.


2015 ◽  
Vol 166 (2) ◽  
pp. 67-74 ◽  
Author(s):  
Rita Bütler ◽  
Markus Bolliger ◽  
Brigitte Commarmot

The search for old-growth forests in Switzerland Old-growth forests and stands have multiple values, such as biological, scientific, socioeconomic, aesthetic, spiritual and cultural ones, but they are very rare in central Europe. Currently, an overview about the existence and size of old-growth forest patches in Switzerland is missing. We propose a definition for old-growth forests worth preserving based on ten criteria: 1) presence of veteran trees, 2) significant biomass, 3) heterogeneous stand structure including senescent and decaying stages, 4) presence of natural processes and disturbances, 5) high dead wood volume (at least 30 m3/ha) and a large diversity of dimensions and decay stages of dead wood pieces, 6) autochthonous tree species, 7) diverse and natural species assemblages, 8) only extensive or no harvesting for the last 50 years, 9) long continuity of forest cover, 10) minimal area of 30 ha for old-growth forests and 1 ha for old-growth stands. When searching for old-growth forests and stands worth preserving, quantitative criteria from the National Forest Inventory and other sources should also be used. We call on all forest specialists to identify old-growth patches, to inform the population and decision makers about their high value, and to protect them in an adequate manner as a unique natural heritage.


2017 ◽  
Vol 7 (1-2) ◽  
pp. 73-107
Author(s):  
Orsolya Perger ◽  
Curtis Rollins ◽  
Marian Weber ◽  
Wiktor Adamowicz ◽  
Peter Boxall

Sign in / Sign up

Export Citation Format

Share Document