Prescribed burning of canopy gaps facilitates tree seedling establishment in restoration of pine-dominated boreal forests

2015 ◽  
Vol 45 (9) ◽  
pp. 1225-1231 ◽  
Author(s):  
Hannes Pasanen ◽  
Virve Rehu ◽  
Kaisa Junninen ◽  
Jari Kouki
Keyword(s):  
Scots Pine ◽  
Boreal Forests ◽  
Forest Restoration ◽  
Prescribed Burning ◽  
Study Groups ◽  
Canopy Gaps ◽  
Canopy Gap ◽  
Tree Seedlings ◽  
Tree Seedling ◽  
Tree Species Composition

Because many currently protected forests are former timber production areas, restoration activities are often used to re-establish their natural structures. In this experimental study, we monitored the establishment of tree seedlings in previously managed but currently protected Scots pine (Pinus sylvestris L.) dominated stands in boreal forests 5 years after restoration measures. The study included eight study areas (115 sample plots) in southern Finland. We compared seedling abundance between five study groups: untreated control forest, unburned canopy gap, burned full-canopy forest, burned canopy gap, and thinned and burned forest. Density of tree seedlings was highest in burned canopy gaps (mean 25.4 seedlings/100 m2 compared with 6.0 seedlings/100 m2 in control sites). In particular, birch (Betula spp.) and Scots pine were significantly more abundant within burned canopy gaps than in unburned gaps. We conclude that opening within-stand canopy gaps, especially in combination with prescribed burning, can be useful in forest restoration as the gaps diversify age-class structure and tree species composition of single-cohort pine stands.

Effects of vegetation cover on seedling and sapling dynamics in secondary tropical wet forests in Costa Rica

2005 ◽  
Vol 22 (1) ◽  
pp. 65-76 ◽  
Author(s):  
Juan Manuel Dupuy ◽  
Robin L. Chazdon
Keyword(s):  
Costa Rica ◽  
Tree Species ◽  
Vegetation Cover ◽  
Secondary Forest ◽  
Canopy Gaps ◽  
Canopy Gap ◽  
Control Treatment ◽  
Secondary Forests ◽  
Tree Seedling ◽  
Understorey Vegetation

We examined effects of experimental manipulations of vegetation cover on recruitment, mortality and density of seedlings (20–100 cm tall) and saplings (≥100 cm tall) of woody growth forms over a 2.5-y period. We created four treatments in each of three 15–20-y-old tropical forest stands in Costa Rica: a large canopy gap (270–350 m2), a small canopy gap (50–100 m2), understorey vegetation removal, and an unmanipulated control treatment. Creation of canopy gaps, especially large ones, increased first-year recruitment and density, as well as overall mortality of seedlings. Saplings experienced lower mortality and more prolonged gap-enhanced recruitment and density than seedlings. Removal of understorey vegetation had little or no effect on tree seedling and sapling dynamics. Recruitment and density of lianas responded only to large gaps, whereas understorey species responded to both gap treatments and to spatial heterogeneity within gaps. Tree species exhibited diverse regeneration requirements, whereas liana and understorey species were more specialized to the high and low ends of the light availability gradient, respectively. Canopy gaps provide a critical mechanism for regeneration of lianas, and canopy tree species that dominate during the early stages of secondary forest succession. The choice of management system for these secondary forests can determine the direction and rate of succession.

scholarly journals Stochastic Economic Analysis of Investment Projects in Forest Restoration Involving Containerized Tree Seedlings in Brazil

Forests ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1381
Author(s):  
Danilo Simões ◽  
Jean Fernando Silva Gil ◽  
Richardson Barbosa Gomes da Silva ◽  
Rafaele Almeida Munis ◽  
Magali Ribeiro da Silva
Keyword(s):  
Survival Rate ◽  
Forest Restoration ◽  
Smallholder Farmers ◽  
Seedling Survival ◽  
Investment Project ◽  
Production Costs ◽  
Tree Seedlings ◽  
Tree Seedling ◽  
Investment Projects ◽  
Polyethylene Bags

Background: Experts in ecological restoration have discussed the cost reduction to make forest restoration financially feasible. This is very important in developing countries, such as Brazil, and for smallholder farmers; however, economic studies do not usually consider the uncertainties in their analysis. Therefore, this study aimed to analyze, under conditions of uncertainty, how tropical tree seedlings produced in polyethylene bags, polyethylene tubes, and biodegradable containers (Ellepot®) interfere with the costs of implementation and post-planting maintenance investment projects in a deforested tropical seasonal forest area in southern Brazil. Methods: We evaluated total costs, production costs, and equivalent annual uniform costs, and the probability distributions and estimated ranges of stochastic values were adjusted through Monte Carlo method simulation. Furthermore, the seedling survival rate was recorded over 12 months post-planting. Results: The costs with tree seedling acquisition and direct labor were the components that most impacted total costs in the three investment projects. The forest restoration investment project with tree seedlings produced in polyethylene bags was economically unfeasible in relation to other projects. Conclusions: The best economic alternative was observed in the investment project with tree seedlings produced in Ellepot®, which showed a survival rate >80% after one year and the lowest total cost, production cost, and equivalent uniform annual cost.

Succession of understory vegetation in managed and seminatural Scots pine forests in eastern Finland and Russian Karelia

2005 ◽  
Vol 35 (6) ◽  
pp. 1422-1441 ◽  
Author(s):  
Anneli Uotila ◽  
Juha-Pekka Hotanen ◽  
Jari Kouki
Keyword(s):  
Forest Management ◽  
Scots Pine ◽  
Prescribed Burning ◽  
Understory Vegetation ◽  
Tree Canopy ◽  
Ground Vegetation ◽  
Tree Seedlings ◽  
Dwarf Shrubs ◽  
Clear Cutting ◽  
Eastern Finland

The aim of this study was to compare the understory vegetation in chronosequences representing seminatural and managed Scots pine (Pinus sylvestris L.) forests on dryish heaths of the Vaccinium type. The data represent the middle boreal vegetation zone and were collected in eastern Finland and the Dvina area of Karelia, on both sides of the border between Finland and the Russian Federation. Species diversity and the coverage of the various life-form groups (ground lichens, mosses, liverworts, grasses, herbs, dwarf shrubs, and tree seedlings) were used to analyse the properties of the ground vegetation over the succession from open forest land to closed forest communities. The clearest differences in diversity between the seminatural forests mainly influenced by fire and managed forests occurred in the early stages of succession. Forest management appeared to increase the species richness at the beginning of succession. The seminatural stands were rich in Cladonia lichens and dwarf shrubs up until tree canopy closure; however, the abundance of mosses was lower in the seminatural stands. Forest management favoured an abundance of grasses, notably Deschampsia flexuosa, which was common after clear-cutting. The use of prescribed burning in silviculture could result in more natural vegetation succession dynamics in managed stands.

scholarly journals Stand Stability of Pure and Mixed-Eucalyptus Forests of Different Tree Species in a Typhoon-Prone Area

Forests ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 458
Author(s):  
Haiyan Deng ◽  
Linlin Shen ◽  
Jiaqi Yang ◽  
Xiaoyong Mo
Keyword(s):  
Tree Species ◽  
Forest Restoration ◽  
Large Scale ◽  
Stand Structure ◽  
Pinus Elliottii ◽  
Stem Form ◽  
Tree Species Composition ◽  
Eucalyptus Plantation ◽  
Mixed Plantation ◽  
Preservation Rate

Background and Objectives: The stable stand structure of mixed plantations is the basis of giving full play to forest ecological function and benefit. However, the monocultural Eucalyptus plantations with large-scale and successive planting that caused ecological problems such as reduced species diversity and loss of soil nutrients have presented to be unstable and vulnerable, especially in typhoon-prone areas. The objective of this study was to evaluate the nonspatial structure difference and the stand stability of pure and mixed-Eucalyptus forests, to find out the best mixed pattern of Eucalyptus forests with the most stability in typhoon-prone areas. Materials and Methods: In this study, we randomly investigated eight plots of 30 m × 30 m in pure and mixed-Eucalyptus (Eucalyptus urophylla S. T. Blake × E. grandis W. Hill) plantations of different tree species (Neolamarckia cadamba (Roxb.) Bosser, Acacia mangium Willd., and Pinus elliottii var. Elliottii Engelm. × P. caribaea Morelet) on growth status, characterized and compared the distribution of nonspatial structure of the monoculture and mixtures, and evaluated the stand quality and stability from eight indexes of the nonspatial structure, including preservation rate, stand density, height, diameter, stem form, degree of stem inclination, tree-species composition, and age structure. Results: Eucalyptus surviving in the mixed plantation of Eucalyptus and A. mangium (EA) and in the mixed plantation of Eucalyptus and P. elliottii × P. caribaea (EP) were 5.0% and 7.6% greater than those in pure Eucalyptus plantation (EE), respectively, while only the stand preservation rate of EA was greater (+2.9%) than that of the pure Eucalyptus plantation. The proportions of all mixtures in the height class greater than 7 m were fewer than that of EE. The proportions of EA and mixed plantation of Eucalyptus and N. cadamba (EN) in the diameter class greater than 7 m were 10.6% and 7.8%, respectively, more than that of EE. EN had the highest ratio of branching visibly (41.0%), EA had the highest ratio of inclined stems (8.1%), and EP had the most straight and complete stem form (68.7%). The stand stability of the mixed plantation of Eucalyptus and A. mangium presented to be optimal, as its subordinate function value (0.76) and state value (ω = 0.61) of real stand were the largest. Conclusions: A. mangium is a superior tree species to mix with Eucalyptus for a more stable stand structure in the early growth stage to approach an evident and immense stability and resistance, which is of great significance for the forest restoration of Eucalyptus in response to extreme climate and forest management.

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.

Distribution of epicormic branches and foliage on Douglas-fir as influenced by adjacent canopy gaps

2018 ◽  
Vol 48 (11) ◽  
pp. 1320-1330
Author(s):  
John W. Punches ◽  
Klaus J. Puettmann
Keyword(s):  
Branch Length ◽  
Canopy Gaps ◽  
Douglas Fir ◽  
Canopy Gap ◽  
Tree Age ◽  
Gap Size ◽  
Terminal Bud ◽  
Total Branch Length ◽  
A Minor ◽  
Epicormic Branches

The influence of adjacent canopy gaps on spatial distribution of epicormic branches and delayed foliage (originating from dormant buds) was investigated in 65-year-old coastal Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco). Sample trees were selected across a broad range of local densities (adjacent canopy gap sizes) from a repeatedly thinned stand in which gaps had been created 12 years prior to our study. Lengths and stem locations of original and epicormic branches were measured within the south-facing crown quadrant, along with extents to which branches were occupied by sequential (produced in association with terminal bud elongation) and (or) delayed foliage. Epicormic branches, while prevalent throughout crowns, contributed only 10% of total branch length and 2% of total foliage mass. In contrast, delayed foliage occupied over 75% of total branch length, accounted for nearly 39% of total foliage mass, and often overlapped with sequential foliage. Canopy gap size did not influence original or epicormic branch length or location. On original branches, larger gaps may have modestly negatively influenced the relative extent of sequential foliage on branches and (or) slightly positively influenced delayed foliage mass. Delayed foliage appears to contribute substantially to Douglas-fir crown maintenance at this tree age, but canopy gap size had a minor influence, at least in the short term.

scholarly journals Evaluation of Tree Seedling Mortality and Protective Strategies in Riparian Forest Restoration

2008 ◽  
Vol 25 (3) ◽  
pp. 117-123 ◽  
Author(s):  
William S. Keeton
Keyword(s):  
Forest Restoration ◽  
Riparian Forest ◽  
Planting Density ◽  
Tree Seedling ◽  
Seedling Mortality ◽  
Order Stream ◽  
Growing Seasons ◽  
Deer Browse ◽  
Limited Effectiveness ◽  
Protective Strategies

Abstract Riparian forest restoration can be severely constrained by tree seedling mortality. I evaluated the effects of tree shelters and planting density on herbivory and seedling mortality at a restoration site in the Lake Champlain Basin of Vermont. Eighteen experimental units were established along a 5th-order stream and planted with bare-root seedlings of seven species associated with northern hardwood floodplain forests. Two treatments were applied in a factorial design: shelters versus no shelters and high versus low planting density. Mortality and herbivory data were collected over three growing seasons. Survivorship declined to 56.4% after three growing seasons and varied significantly by species. Planting density, presence/absence of shelters, and their interaction had significant effects on survival, browse, or girdling intensity when tested for all species combined. Browse rates were high (44%), whereas girdling rates were low (3.4%). Both browse (P < 0.001) and girdling (P = 0.022) contributed to seedling mortality. High rates of deer browse on seedlings in shelters were due, in part, to the short height (60 cm) of the shelters, suggesting a need for taller shelters. A large portion (39%) of dead seedlings were neither browsed nor girdled, signaling the importance of other mortality agents. An adaptive approach is recommended to compensate for high seedling mortality and the limited effectiveness of protective devices.

Paludification and management of forested peatlands in Canada: a literature review

2005 ◽  
Vol 13 (2) ◽  
pp. 21-50 ◽  
Author(s):  
Martin Lavoie ◽  
David Paré ◽  
Nicole Fenton ◽  
Arthur Groot ◽  
Kim Taylor
Keyword(s):  
Organic Matter ◽  
Boreal Forests ◽  
Prescribed Burning ◽  
Soil Disturbance ◽  
Negative Effects ◽  
Internal Factors ◽  
Temperature Decomposition ◽  
Past Experiences ◽  
Lower Site ◽  
Water Table Rise

The Clay Belt region of Quebec and Ontario supports a large forest resource and an important forest industry. In this region, the majority of the harvested volume allotted to forest companies is in forested peatlands and boreal forests prone to paludification. Paludification is the accumulation of organic matter over time, and is generally believed to be caused by increasing soil moisture and Sphagnum colonization. Paludification is influenced by external and internal factors; it reduces soil temperature, decomposition rates, microbial activity, and nutrient availability. As a result, paludification may lead to lower site productivity with time after disturbance. Therefore, in harvested stands with a thick organic matter layer, low soil disturbance (as opposed to fire) and water table rise may create favourable conditions for paludification that may ultimately be detrimental to timber production. Past experiences suggest several solutions to prevent or control the negative effects of paludification. Drainage and fertilization applied together are generally good techniques to control paludification and to improve tree productivity. On the other hand, we suggest that site preparation as well as prescribed burning, preceded or not by drainage, are avenues of research that deserve to be explored because they hold the potential to control or even reverse paludification, especially where peat accumulation is caused by natural succession or where lateral peat expansion has occurred. Key words: paludification, forested peatland, productivity, wildfire, careful logging, soil disturbance.

scholarly journals Sensitivity of managed boreal forests in Finland to climate change, with implications for adaptive management

2007 ◽  
Vol 363 (1501) ◽  
pp. 2339-2349 ◽  
Author(s):  
Seppo Kellomäki ◽  
Heli Peltola ◽  
Tuula Nuutinen ◽  
Kari T Korhonen ◽  
Harri Strandman
Keyword(s):  
Climate Change ◽  
Norway Spruce ◽  
Scots Pine ◽  
Boreal Forests ◽  
Forest Growth ◽  
Forest Land ◽  
Forest Zone ◽  
The North ◽  
Northern Forests ◽  
Climate Change Model

This study investigated the sensitivity of managed boreal forests to climate change, with consequent needs to adapt the management to climate change. Model simulations representing the Finnish territory between 60 and 70° N showed that climate change may substantially change the dynamics of managed boreal forests in northern Europe. This is especially probable at the northern and southern edges of this forest zone. In the north, forest growth may increase, but the special features of northern forests may be diminished. In the south, climate change may create a suboptimal environment for Norway spruce. Dominance of Scots pine may increase on less fertile sites currently occupied by Norway spruce. Birches may compete with Scots pine even in these sites and the dominance of birches may increase. These changes may reduce the total forest growth locally but, over the whole of Finland, total forest growth may increase by 44%, with an increase of 82% in the potential cutting drain. The choice of appropriate species and reduced rotation length may sustain the productivity of forest land under climate change.

scholarly journals Prediction of photosynthesis in Scots pine ecosystems across Europe by a needle-level theory

2018 ◽  
Vol 18 (18) ◽  
pp. 13321-13328
Author(s):  
Pertti Hari ◽  
Steffen Noe ◽  
Sigrid Dengel ◽  
Jan Elbers ◽  
Bert Gielen ◽  
...  
Keyword(s):  
Scots Pine ◽  
Boreal Forests ◽  
Co2 Flux ◽  
Field Studies ◽  
Co2 Assimilation ◽  
Co2 Fluxes ◽  
New Era ◽  
Evergreen Forests ◽  
Transition Times

Abstract. Photosynthesis provides carbon for the synthesis of macromolecules to construct cells during growth. This is the basis for the key role of photosynthesis in the carbon dynamics of ecosystems and in the biogenic CO2 assimilation. The development of eddy-covariance (EC) measurements for ecosystem CO2 fluxes started a new era in the field studies of photosynthesis. However, the interpretation of the very variable CO2 fluxes in evergreen forests has been problematic especially in transition times such as the spring and autumn. We apply two theoretical needle-level equations that connect the variation in the light intensity, stomatal action and the annual metabolic cycle of photosynthesis. We then use these equations to predict the photosynthetic CO2 flux in five Scots pine stands located from the northern timberline to Central Europe. Our result has strong implications for our conceptual understanding of the effects of the global change on the processes in boreal forests, especially of the changes in the metabolic annual cycle of photosynthesis.

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