Long-term effects of stump removal and tree species composition on the diversity and structure of soil fungal communities

2020 ◽  
Vol 96 (5) ◽  
Author(s):  
Dixi Modi ◽  
Suzanne Simard ◽  
Jean Bérubé ◽  
Les Lavkulich ◽  
Richard Hamelin ◽  
...  

ABSTRACT Stump removal is a common forest management practice used to reduce the mortality of trees affected by the fungal pathogen-mediated root disease, Armillaria root rot, but the impact of stumping on soil fungal community structure is not well understood. This study analyzed the long-term impact of stumping and tree species composition on the abundance, diversity and taxonomic composition of soil fungal communities using internal transcribed spacer (ITS) marker-based DNA metabarcoding in a 48-year-old trial at Skimikin, British Columbia. A total of 108 samples were collected from FH (fermented and humus layers), and soil mineral horizons (A and B) from stumped and unstumped plots of six tree species treatments (pure stands and admixtures of Douglas-fir, western red-cedar and paper birch). Fungal α-diversity in the A horizon significantly increased with stumping regardless of tree species composition, while β-diversity was significantly affected by stumping in all the horizons. We also observed that the relative abundance of the saprotrophic fungal community declined while that of the ectomycorrhizal fungal community increased with stumping. In conclusion, increase in ectomycorrhizal fungal associations, which are positively associated with tree productivity, suggests that stumping can be considered a good management practice for mitigating root disease and promoting tree regeneration.

2003 ◽  
Vol 79 (2) ◽  
pp. 227-232 ◽  
Author(s):  
Andrej Boncina ◽  
Franc Gaspersic ◽  
Jurij Diaci

This study utilizes data from long-term research sites in managed fir-beech forests (Hrusica, Leskova dolina and Rog) and a virgin forest remnant (Rajhenav), used as a reference site. Data obtained from old forest management plans and forest inventories were analysed. The results of the study support the hypothesis that two main tree species—silver fir (Abies alba Mill.) and European beech (Fagus sylvatica L.)—alternate site dominance. The causes of species dominance alternation include both natural processes and anthropogenic factors, in particular silvicultural practices and the impact of ungulates. More than a hundred years ago, European beech dominated stand volume. The proportion of silver fir increased until 1940–1970 when a gradual decrease started. All indicators suggest that the proportion of silver fir will decrease further in the coming decades. Key words: tree species composition alternation, diameter distribution, silver fir, European beech, forest history, forest planning, managed forests, virgin forest remnant


2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Xavier Morin ◽  
Lorenz Fahse ◽  
Hervé Jactel ◽  
Michael Scherer-Lorenzen ◽  
Raúl García-Valdés ◽  
...  

2015 ◽  
Vol 45 (9) ◽  
pp. 1215-1224 ◽  
Author(s):  
Per-Ola Hedwall ◽  
Grzegorz Mikusiński

Protected forest areas (PFAs) are key features of biodiversity conservation, and knowledge about long-term development is crucial in evaluating their efficiency and management needs. Longitudinal data on forest structure in PFAs is uncommon and often from small areas. Here we use data from the Swedish National Forest Inventory to study changes in more than 750 000 ha of PFAs over 60 years. Structures important for biodiversity, e.g., number of large trees and the volume of hard deadwood, including both standing and down wood, have more than doubled. The initial volume of deadwood, however, was very low. The overall tree species composition was stable over time, and only among the largest trees were there indications of a shift towards the late successional Norway spruce (Picea abies (L.) Karst.). Deadwood increased independent of species, size of wood, and site characteristics. This increase was positively related to the volume of living trees and forest age. We conclude that Swedish PFAs, in the absence of active management and under fire suppression at the landscape scale, develop structural components that are crucial for conservation of biodiversity. However, although tree species composition appears stable, present disturbance regimes in the PFAs are considerably different from those in naturally dynamic forests, which may have implications for long-term biodiversity maintenance.


2016 ◽  
Vol 47 (2) ◽  
pp. 115 ◽  
Author(s):  
Christiana Ndidi Egbinola

The study investigated the tree species composition along the forest-savanna boundary in Oyo state of Nigeria with the aim of assessing the impact of human activities on the floristic composition. A transect was placed along the study area and species data was collected from quadrats placed in study plots within different study sites. Detrended Correspondence Analysis (DCA) was used to determine vegetation assemblages, while both correlation and the analysis of variance (ANOVA) were used to show the relationship between species in the different study sites. Results of the DCA revealed three species assemblages, an area with only forest species, another with only savanna species and a third with both forest/savanna species. ANOVA results further revealed that within the forest and savanna assemblages, species in mature and successional sites were alike. The study therefore revealed that human activities’ within the region is leading to the establishment of savanna species and an elimination of forest species.


Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1116 ◽  
Author(s):  
Mark B. Burnham ◽  
Martin J. Christ ◽  
Mary Beth Adams ◽  
William T. Peterjohn

Many factors govern the flow of deposited nitrogen (N) through forest ecosystems and into stream water. At the Fernow Experimental Forest in WV, stream water nitrate (NO3−) export from a long-term reference watershed (WS 4) increased in approximately 1980 and has remained elevated despite more recent reductions in chronic N deposition. Long-term changes in species composition may have altered forest N demand and the retention of deposited N. In particular, the abundance and importance value of Acer saccharum have increased since the 1950s, and this species is thought to have a low affinity for NO3−. We measured the relative uptake of NO3− and ammonium (NH4+) by six important temperate broadleaf tree species and estimated stand uptake of total N, NO3−, and NH4+. We then used records of stream water NO3− and stand composition to evaluate the potential impact of changes in species composition on NO3− export. Surprisingly, the tree species we examined all used both mineral N forms approximately equally. Overall, the total N taken up by the stand into aboveground tissues increased from 1959 through 2001 (30.9 to 35.2 kg N ha−1 yr−1). However, changes in species composition may have altered the net supply of NO3− in the soil since A. saccharum is associated with high nitrification rates. Increases in A. saccharum importance value could result in an increase of 3.9 kg NO3−-N ha−1 yr−1 produced via nitrification. Thus, shifting forest species composition resulted in partially offsetting changes in NO3− supply and demand, with a small net increase of 1.2 kg N ha−1 yr−1 in NO3− available for leaching. Given the persistence of high stream water NO3− export and relatively abrupt (~9 year) change in stream water NO3− concentration circa 1980, patterns of NO3− export appear to be driven by long-term deposition with a lag in the recovery of stream water NO3− after more recent declines in atmospheric N input.


2017 ◽  
Vol 23 (8) ◽  
pp. 3154-3168 ◽  
Author(s):  
István Fekete ◽  
Kate Lajtha ◽  
Zsolt Kotroczó ◽  
Gábor Várbíró ◽  
Csaba Varga ◽  
...  

2012 ◽  
Vol 52 (No. 2) ◽  
pp. 74-91 ◽  
Author(s):  
I. Štefančík

The paper is a contribution to the research on problems of thinnings in mixed (spruce-fir-beech) stands situated in the 5<sup>th</sup> forest altitudinal zone (beech with fir) in the central part of Slovakia. The research was carried out on two series of permanent research plots established in 1972. Each of the series consists of three partial plots where one plot was tended by free crown thinning in the framework of whole-area tending. On the second plot a non-whole-area tending was realised while the third ones were left without planned silvicultural treatment as controls. Dynamic changes in tree species composition, stand structure, qualitative and quantitative production including silvicultural analysis of seven thinning interventions were evaluated for a period of 29 years. A&nbsp;special attention was paid to development of future crop trees which are the main bearers of stand quality and quantity. The changes were compared with respect to differences between the plots with whole-area and non-whole-area long-term silvicultural treatment and the control plot (without treatments).


Land ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 126
Author(s):  
Brigite Botequim ◽  
Miguel N. Bugalho ◽  
Ana Raquel Rodrigues ◽  
Susete Marques ◽  
Marco Marto ◽  
...  

Sustainable forest management needs to address biodiversity conservation concerns. For that purpose, forest managers need models and indicators that may help evaluate the impact of management options on biodiversity under the uncertainty of climate change scenarios. In this research we explore the potential for designing mosaics of stand-level forest management models to address biodiversity conservation objectives on a broader landscape-level. Our approach integrates (i) an effective stand-level biodiversity indicator that reflect tree species composition, stand age, and understory coverage under divergent climate conditions; and (ii) linear programming optimization techniques to guide forest actors in seeing optimal forest practices to safeguard future biodiversity. Emphasis is on the efficiency and effectiveness of an approach to help assess the impact of forest management planning on biodiversity under scenarios of climate change. Results from a resource capability model are discussed for an application to a large-scale problem encompassing 14,765 ha, extending over a 90-years planning horizon and considering two local-climate scenarios. They highlight the potential of the approach to help assess the impact of both stand and landscape-level forest management models on biodiversity conservation goals. They demonstrate further that the approach provides insights about how climate change, timber demand and wildfire resistance may impact plans that target the optimization of biodiversity values. The set of optimized long-term solutions emphasizes a multifunctional forest that guarantees a desirable local level of biodiversity and resilience to wildfires, while providing a balanced production of wood over time at the landscape scale.


2020 ◽  
Vol 97 (1) ◽  
Author(s):  
Dixi Modi ◽  
Suzanne Simard ◽  
Les Lavkulich ◽  
Richard C Hamelin ◽  
Sue J Grayston

ABSTRACT Stumping is an effective forest management practice for reducing the incidence of Armillaria root-rot in regenerating trees, but its impact on the soil bacterial community has not been ascertained. This study investigated the long-term impact of stumping and tree species composition in a 48-year-old trial at Skimikin, British Columbia, on the relative abundance, diversity and taxonomic composition of bacterial communities by sequencing the v4 region of 16S rRNA gene using the Illumina Miseq platform. A total of 108 samples were collected from the forest floor (fermented (F) and humus (H) layers) and mineral soil (A (0–10 cm) and B (10–20 cm) horizons) of 36 plots (half each stumped or unstumped) that were planted with pure stands and admixtures of Douglas-fir, western redcedar and paper birch. Bacterial α-diversity in the B horizon declined with stumping whereas β-diversity was affected both by tree species and stumping treatments, with fir and birch supporting distinct bacterial communities. All horizons of stumped plots of birch and its admixtures were significantly enriched with potential plant growth-promoting bacteria. In conclusion, stumping along with planting birch alone or in admixture with other species promotes a bacterial microbiome that appears beneficial in the suppression of root disease.


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