Influence of Site and Stand Factors on the Distribution of Crustose Lichens Of The Caliciales in a Suboceanic Spruce Forest Area in Central Norway

1996 ◽  
Vol 28 (4) ◽  
pp. 315-330 ◽  
Author(s):  
Håkon Holien
Keyword(s):  
Species Diversity ◽  
Boreal Forests ◽  
Detrended Correspondence Analysis ◽  
Stand Age ◽  
Spruce Forest ◽  
Humid Climate ◽  
Forest Patches ◽  
Young Forests ◽  
Old Trees ◽  
Crustose Lichens

AbstractThe distribution of crustose Caliciales has been surveyed in 100 spruce forest patches in Sør-Trøndelag, central Norway. Relationships between occurrence of the species and a number of site and stand variables were analysed by detrended correspondence analysis (DCA) and direct gradient analysis. Species diversity7 was significantly higher in old forests and in forests at higher altitudes compared to young forests and forests at lower altitudes. Old trees and snags are considered to be the most important structural components in old forests promoting species diversity of the Caliciales. Threatened or vulnerable species, such as Chaenotheca gracilliina, Cybebe gracilenta, Sclerophora coniophaea and S. peronella were confined to forest on rich soils showing no correlation with forest stand age. Chaenotheca brachypoda and C. trichialis were found to be the most typical old forest species among the Caliciales. Humidiphilous species are considered to be less affected by forestry in a humid climate. A change in forestry practice towards methods imitating the natural dynamic processes is considered necessary to maintain species diversity of the Caliciales in boreal forests.

scholarly journals Linking hypothesized causal factors to aboveground biomass growth in forests of Alabama and the eastern United States

2018 ◽  
Vol 26 (3) ◽  
pp. e016 ◽  
Author(s):  
Santosh K. Ojha ◽  
Luben D. Dimov
Keyword(s):  
Species Richness ◽  
Species Diversity ◽  
Relative Density ◽  
Stand Age ◽  
Path Coefficient ◽  
Eastern Region ◽  
Biomass Growth ◽  
Lower Productivity ◽  
Young Forests ◽  
Positive Direct

Aim of study: We analyzed the hypothesized causal effects of relative density, density, height, species richness, species diversity, temperature, precipitation, and slope on above ground biomass growth (AGBG).Area of study: Eastern region of the USA.Materials and methods: We used the USDA Forest Service’s Forest Inventory and Analysis (FIA) database. A total of 2554 plots from all stand ages, regardless of disturbance history, were selected from the state of Alabama and 967 plots of stand age under 30 years and no prior disturbance were selected from the eastern US. We analyzed the data using descriptive statistics and structural equation modeling.Main results: Relative stand density exhibited a strong positive direct effect on AGBG, especially in the young forests (path coefficient 0.79), but a weaker indirect effect through species richness/diversity. Tree height influenced positively AGBG directly and indirectly through relative density and species richness. The effect of temperature and slope was greater than the effect of species richness/diversity on AGBG in the young forests of the eastern US.Research highlights: For the forests of the eastern US, greater tree species diversity did not appear to result in neither greater nor lower productivity. The diversity-productivity relationship was negative in forests of Alabama, however, where prior management likely resulted in removal of select dominant trees from valuable species (i.e., high-grading). 

Influence of Stand Age And Structure on the Epiphytic Lichen Vegetation in the Middle-Boreal Forests of Finland

1992 ◽  
Vol 24 (2) ◽  
pp. 165-180
Author(s):  
M. Hyvärinen ◽  
P. Halonen ◽  
M. Kauppi
Keyword(s):  
Boreal Forests ◽  
Environmental Variables ◽  
Competitive Ability ◽  
Lichen Species ◽  
Tree Canopy ◽  
Stand Age ◽  
Ecological Strategy ◽  
Epiphytic Lichen ◽  
Vertical Location ◽  
Community Variation

Abstract The epiphytic lichen vegetation on the trunks of Pinus sylvestris and Picea abies was studied and analysed by canonical correspondence analysis in relation to a number of environmental variables. The distribution and abundance of epiphytic lichen species proved to be dependent on the age of the stand, showing divergent responses in relation to phorophyte species and environmental variables such as acidity of the bark and vertical location on the trunk. The importance of stand age in the pattern of community variation is concluded to be an outcome of interaction between changes in the structure of the tree canopy, microclimate and properties of the bark. The responses of single lichen species to changes in the environment seem to vary considerably, indicating differences in competitive ability and ecological strategy between the species.

Diversification of tree stands as a means to manage pests and diseases in boreal forests: myth or reality?

2006 ◽  
Vol 36 (2) ◽  
pp. 324-336 ◽  
Author(s):  
Julia Koricheva ◽  
Harri Vehviläinen ◽  
Janne Riihimäki ◽  
Kai Ruohomäki ◽  
Pekka Kaitaniemi ◽  
...  
Keyword(s):  
Species Diversity ◽  
Tree Species ◽  
Boreal Forests ◽  
Tree Mortality ◽  
Tree Species Diversity ◽  
Mixed Stands ◽  
Tree Species Composition ◽  
Pests And Diseases ◽  
Pest Outbreaks ◽  
Disease Epidemics

Pure forest stands are widely believed to be more prone to pest outbreaks and disease epidemics than mixed stands, leading to recommendations of using stand diversification as a means of controlling forest pests and pathogens. We review the existing evidence concerning the effects of stand tree-species diversity on pests and pathogens in forests of the boreal zone. Experimental data from published studies provide no overall support for the hypothesis that diversification of tree stands can prevent pest outbreaks and disease epidemics. Although beneficial effects of tree-species diversity on stand vulnerability are observed in some cases, in terms of reductions in damage, these effects are not consistent over time and space and seem to depend more on tree-species composition than on tree-species diversity per se. In addition, while mixed stands may reduce the densities of some specialized herbivores, they may be more attractive to generalist herbivores. Given that generalist mammalian herbivores cause considerable tree mortality during the early stages of stand establishment in boreal forests, the net effect of stand diversification on stand damage is unlikely to be positive.

Saproxylic insect assemblages in Canadian forests: diversity, ecology, and conservation

2008 ◽  
Vol 140 (4) ◽  
pp. 453-474 ◽  
Author(s):  
David W. Langor ◽  
H.E. James Hammond ◽  
John R. Spence ◽  
Joshua Jacobs ◽  
Tyler P. Cobb
Keyword(s):  
Forest Management ◽  
Boreal Forests ◽  
Dead Wood ◽  
Sustainable Forest Management ◽  
Forest Harvesting ◽  
Stand Age ◽  
Managed Forests ◽  
Saproxylic Insects ◽  
Associated Species ◽  
Experimental Burns

AbstractSaproxylic insect assemblages inhabiting dead wood in Canadian forests are highly diverse and variable but quite poorly understood. Adequate assessment of these assemblages poses significant challenges with respect to sampling, taxonomy, and analysis. Their assessment is nonetheless critical to attaining the broad goals of sustainable forest management because such species are disproportionately threatened elsewhere by the reductions in dead wood generally associated with commercial exploitation of northern forests. The composition of the saproxylic fauna is influenced by many factors, including tree species, degree of decay, stand age, and cause of tree death. Wildfire and forest harvesting have differential impacts on saproxylic insect assemblages and on their recovery in postdisturbance stands. Exploration of saproxylic insect responses to variable retention harvesting and experimental burns is contributing to the development of prescriptions for conserving saproxylic insects in boreal forests. Understanding of processes that determine diversity patterns and responses of saproxylic insects would benefit from increased attention to natural history. Such work should aim to provide a habitat-classification system for dead wood to better identify habitats (and associated species) at risk as a result of forest management. This tool could also be used to improve strategies to better maintain saproxylic organisms and their central nutrient-cycling functions in managed forests.

scholarly journals Forest and forest succession in Hong Kong, China

1997 ◽  
Vol 13 (6) ◽  
pp. 857-866 ◽  
Author(s):  
Xue Ying Zhuang ◽  
Richard T. Gorlett
Keyword(s):  
Hong Kong ◽  
Forest Cover ◽  
Forest Succession ◽  
Secondary Forest ◽  
Complex Structure ◽  
Detrended Correspondence Analysis ◽  
Feng Shui ◽  
Forest Patches ◽  
Northern Margin ◽  
Current Species

ABSTRACTHong Kong is on the northern margin of the Asian tropics. The original forest cover was cleared centuries ago but secondary forest has developed since 1945 at many sites protected from fire and cutting. There are also older forest patches maintained behind villages for reasons of ‘feng shui’, the Chinese system of geomancy. All plants >2 cm dbh were identified and measured in forty-four 400-m2 plots. Detrended correspondence analysis showed a floristic continuum, with the montane sites (>500 m) most distinct and some overlap between lowland post-1945 secondary forest and the feng shui woods. The 30–40 year-old secondary forest is dominated by Persea spp. Montane forest is similar but lacks several common lowland taxa of tropical genera and includes more subtropical taxa. The feng shui woods have the most complex structure and contain some tree species not found in other forest types. Their origin and history is obscure but we suggest that both planting and selective harvesting have had a role in their current species composition

scholarly journals Estimation of Fungal Diversity and Identification of Major Abiotic Drivers Influencing Fungal Richness and Communities in Northern Temperate and Boreal Quebec Forests

Forests ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 1096 ◽  
Author(s):  
Laperriere Genevieve ◽  
Chagnon Pierre-Luc ◽  
Giguère-Tremblay Roxanne ◽  
Morneault Amélie ◽  
Bisson Danny ◽  
...  
Keyword(s):  
Soil Ph ◽  
Fungal Community ◽  
Boreal Forests ◽  
Fungal Diversity ◽  
Linear Models ◽  
Species Conservation ◽  
Environmental Filtering ◽  
Operational Taxonomic Unit ◽  
Stand Age ◽  
High Turnover

Fungi play important roles in forest ecosystems and understanding fungal diversity is crucial to address essential questions about species conservation and ecosystems management. Changes in fungal diversity can have severe impacts on ecosystem functionality. Unfortunately, little is known about fungal diversity in northern temperate and boreal forests, and we have yet to understand how abiotic variables shape fungal richness and composition. Our objectives were to make an overview of the fungal richness and the community composition in the region and identify their major abiotic drivers. We sampled 262 stands across the northern temperate and boreal Quebec forest located in the region of Abitibi-Témiscamingue, Mauricie, and Haute-Mauricie. At each site, we characterized fungal composition using Illumina sequencing, as well as several potential abiotic drivers (e.g., humus thickness, soil pH, vegetation cover, etc.). We tested effects of abiotic drivers on species richness using generalized linear models, while difference in fungal composition between stands was analyzed with permutational multivariate analysis of variance and beta-diversity partitioning analyses. Fungi from the order Agaricales, Helotiales, and Russulales were the most frequent and sites from the north of Abitibi-Témiscamingue showed the highest OTUs (Operational Taxonomic Unit) richness. Stand age and moss cover were the best predictors of fungal richness. On the other hand, the strongest drivers of fungal community structure were soil pH, average cumulative precipitation, and stand age, although much of community variance was left unexplained in our models. Overall, our regional metacommunity was characterized by high turnover rate, even when rare OTUs were removed. This may indicate strong environmental filtering by several unmeasured abiotic filters, or stronger than expected dispersal limitations in soil fungal communities. Our results show how difficult it can be to predict fungal community assembly even with high replication and efforts to include several biologically relevant explanatory variables.

Some climatic aspects of biomass productivity of white spruce stem wood

1987 ◽  
Vol 17 (9) ◽  
pp. 1075-1079 ◽  
Author(s):  
L. A. Jozsa ◽  
J. M. Powell
Keyword(s):  
Boreal Forests ◽  
Biomass Productivity ◽  
White Spruce ◽  
Ice Age ◽  
Stem Wood ◽  
Breast Height ◽  
Sampling Locations ◽  
Tree Ring Data ◽  
Canadian Boreal Forest ◽  
Old Trees

Biomass productivity was determined for white spruce (Piceaglauca (Moench) Voss) in the boreal forests of Alberta, the Northwest Territories, and Manitoba. Comparisons were made between southern and northern locations, between eastern and western transect locations, and between older (200 + years) and younger (110 years) trees. At 13 sampling locations, X-ray densitometric tree ring data were obtained from the base of the stem, breast height, and from five points equidistant along the stem. Markedly higher stem wood biomass productivity was found for the 110-year-old trees than for the 210-year-old trees in Alberta; average ring weights were 3.8 and 1.2 g for the first 100 years of growth in 1 cm thick disks at breast height. These results suggest that climatic warming since the end of the Little Ice Age (ca. 1850) has resulted in higher biomass productivity in the Canadian boreal forest.

The effect of stand age on CO2 efflux from wood ant (Formica rufa group) mounds in boreal forests

2012 ◽  
Vol 52 ◽  
pp. 21-28 ◽  
Author(s):  
Mizue Ohashi ◽  
Timo Domisch ◽  
Leena Finér ◽  
Martin F. Jurgensen ◽  
Liselotte Sundström ◽  
...  
Keyword(s):  
Boreal Forests ◽  
Stand Age ◽  
Co2 Efflux ◽  
Formica Rufa ◽  
Formica Rufa Group

Factors controlling epiphytic lichen biomass during postfire succession in black spruce boreal forests

2009 ◽  
Vol 39 (11) ◽  
pp. 2168-2179 ◽  
Author(s):  
Catherine Boudreault ◽  
Yves Bergeron ◽  
Darwyn Coxson
Keyword(s):  
Boreal Forests ◽  
Stand Structure ◽  
Black Spruce ◽  
Tree Age ◽  
Stand Age ◽  
Epiphytic Lichens ◽  
Dominant Group ◽  
Epiphytic Lichen ◽  
Structure Tree ◽  
Species Groups

Alectorioid lichens are the dominant group of epiphytic lichens in boreal forests. Epiphytic lichen richness and abundance generally increase with stand age and within-stand heterogeneity. The objective of this study was to evaluate the importance of time elapsed since the last fire, stand structure, tree size, tree age, and branch height for epiphytic lichen biomass of the boreal forest of western Quebec. We sampled 12 sites belonging to four forest age classes (from 50 to >200 years). We assessed epiphytic lichen biomass of three species groups ( Bryoria , Evernia , and Usnea ) on 12 trees in each site. Our results showed that biomass of Bryoria and Usnea was higher in intermediate stages (between 101 and 200 years) compared with younger (50–100 years) and older (>200 years) stages. Biomass of the three species groups was greater on larger diameter trees (>16 cm) compared with smaller ones (<16 cm). These results indicate that the protection of postfire stands aged between 101 and 200 year should be prioritized to maintain the functional role of epiphytic lichens in managed landscapes.

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