The effects of fire and stand age on seedling establishment of Pulsatilla patens in a pine-dominated boreal forest

2005 ◽  
Vol 83 (6) ◽  
pp. 688-693 ◽  
Author(s):  
Rein Kalamees ◽  
Kersti Püssa ◽  
Ilkka Vanha-Majamaa ◽  
Kristjan Zobel
Keyword(s):  
Boreal Forest ◽  
Stand Age ◽  
Light Conditions ◽  
Clear Cut ◽  
Forest Sites ◽  
Tree Layer ◽  
Negative Effect ◽  
Scots Pine Forest ◽  
Pulsatilla Patens ◽  
Successional Age

Successful management of disturbance-related endangered plant species requires thorough knowledge concerning their recruitment ecology. Pulsatilla patens (L.) Mill. is found in northern European forests that in the past have been subjected to a periodic wildfire regime and, thus, is supposedly adapted to corresponding changes in forest light conditions and thickness of the moss and litter layers. We tested whether this is true in a field experiment where seeds of P. patens were sown in experimentally burned and control boreal Scots pine forest sites of different successional age (clear-cut, 30 years old, 45 years old). The germination and early establishment of P. patens was enhanced in the experimentally burned conditions and was more successful in younger successional stages. On the other hand, in sites with a tree layer, the germination of P. patens was better in relatively darker areas, suggesting that the negative effect of successional age is probably not a result of changing light conditions, but rather a result of thicker moss and litter layers in the later successional stages.Key words: boreal forest, germination, forest fire, litter layer, Pulsatilla patens, seed sowing.

The effect of soil temperature and light on sprouting and rooting of root cuttings of hybrid aspen clones

2005 ◽  
Vol 35 (11) ◽  
pp. 2671-2678 ◽  
Author(s):  
N Stenvall ◽  
T Haapala ◽  
S Aarlahti ◽  
P Pulkkinen
Keyword(s):  
Soil Temperature ◽  
Populus Tremuloides ◽  
Hybrid Aspen ◽  
Light Conditions ◽  
Dark Treatment ◽  
Sand Mixture ◽  
Negative Effect ◽  
Soil Temperatures ◽  
Time Required ◽  
Better Than

Root cuttings from five clones of hybrid aspen (Populus tremula L. × Populus tremuloides Michx.) obtained from 2-year-old stock plants were grown in a peat–sand mixture (soil) at four soil temperatures (18, 22, 26, and 30 °C). Half of the cuttings were grown in light and the rest in darkness. The root cuttings that were grown at the highest soil temperature sprouted and rooted significantly better than the cuttings grown at the lower temperatures. Light did not affect the sprouting of root cuttings but did have a negative effect on their rooting. Moreover, the clones varied significantly in sprouting and rooting percentages, as well as in the time required for sprouting. In general, higher soil temperatures hastened sprouting of the cuttings. Sprouting was also faster in the light than in the dark treatment. Differences in soil temperature, light conditions, or clone had no significant effect on rooting time.

scholarly journals Constraining ecosystem model with Adaptive Metropolis algorithm using boreal forest site eddy covariance measurements

2016 ◽  
Author(s):  
Jarmo Mäkelä ◽  
Jouni Susiluoto ◽  
Tiina Markkanen ◽  
Mika Aurela ◽  
Ivan Mammarella ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Gross Primary Production ◽  
Co2 Concentration ◽  
Moisture Stress ◽  
Ecosystem Model ◽  
Metropolis Algorithm ◽  
Forest Site ◽  
Diurnal Cycles ◽  
Forest Sites ◽  
Eddy Covariance Measurements

Abstract. We examined parameter optimization in JSBACH ecosystem model, applied for two boreal forest sites in Finland. We identified and tested key parameters in soil hydrology and forest water and carbon exchange related formulations and optimized them using the Adaptive Metropolis algorithm for a five year calibration period (2000–2004) followed by a four year validation period (2005–2008). We were able to improve the modelled seasonal, daily and diurnal cycles of gross primary production and evapotranspiration but unable to enhance the models response to dryness. The improvements are mostly accounted for by parameters related to the ratio of leaf internal CO2 concentration to external CO2, relative humidity, transpiration and soil moisture stress.

scholarly journals Effect of stand age on whole ecosystem CO2exchange in the Canadian boreal forest

2003 ◽  
Vol 108 (D3) ◽  
pp. n/a-n/a ◽  
Author(s):  
Marcy Litvak ◽  
Scott Miller ◽  
Steve C. Wofsy ◽  
Michael Goulden
Keyword(s):  
Boreal Forest ◽  
Stand Age ◽  
Canadian Boreal Forest

Summary and Synthesis: Past and Future Changes in the Alaskan Boreal Forest

2006 ◽  
Author(s):  
Marilyn W. Walker ◽  
Mary E. Edwards
Keyword(s):  
Boreal Forest ◽  
Bark Beetles ◽  
Fire Regime ◽  
Black Spruce ◽  
Rapid Change ◽  
White Spruce ◽  
Late Glacial ◽  
Fire Frequency ◽  
Tree Resistance ◽  
Forest Sites

Historically the boreal forest has experienced major changes, and it remains a highly dynamic biome today. During cold phases of Quaternary climate cycles, forests were virtually absent from Alaska, and since the postglacial re-establishment of forests ca 13,000 years ago, there have been periods of both relative stability and rapid change (Chapter 5). Today, the Alaskan boreal forest appears to be on the brink of further significant change in composition and function triggered by recent changes that include climatic warming (Chapter 4). In this chapter, we summarize the major conclusions from earlier chapters as a basis for anticipating future trends. Alaska warmed rapidly at the end of the last glacial period, ca 15,000–13,000 years ago. Broadly speaking, climate was warmest and driest in the late glacial and early Holocene; subsequently, moisture increased, and the climate gradually cooled. These changes were associated with shifts in vegetation dominance from deciduous woodland and shrubland to white spruce and then to black spruce. The establishment of stands of fire-prone black spruce over large areas of the boreal forest 5000–6000 years ago is linked to an apparent increase in fire frequency, despite the climatic trend to cooler and moister conditions. This suggests that long-term features of the Holocene fire regime are more strongly driven by vegetation characteristics than directly by climate (Chapter 5). White spruce forests show decreased growth in response to recent warming, because warming-induced drought stress is more limiting to growth than is temperature per se (Chapters 5, 11). If these environmental controls persist, projections suggest that continued climate warming will lead to zero net annual growth and perhaps the movement of white spruce to cooler upland forest sites before the end of the twenty-first century. At the southern limit of the Alaskan boreal forest, spruce bark beetle outbreaks have decimated extensive areas of spruce forest, because warmer temperatures have reduced tree resistance to bark beetles and shortened the life cycle of the beetle from two years to one, shifting the tree-beetle interaction in favor of the insect (Chapter 9).

scholarly journals Nutrient Allocation to Different Compartments of Age-Sequence Larch Plantations in China

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 759
Author(s):  
Hongxing Wang ◽  
Dongsheng Chen ◽  
Xiaomei Sun
Keyword(s):  
Soil Nutrients ◽  
Soil Nutrient ◽  
Stand Age ◽  
Nutrient Allocation ◽  
Nutrient Losses ◽  
Nutrient Return ◽  
Nutrient Pools ◽  
Clear Cut ◽  
Nutrient Amounts ◽  
Whole Tree Harvesting

Increased demand for forest-derived biomass has led to more intensive harvesting practices. However, the export of large nutrient quantities with the harvested biomass may lead to the depletion of soil nutrients. Therefore, improved knowledge concerning macronutrient allocation (N, P, K, Ca, and Mg) to different components in forests along age sequences is crucial for their sustainable management. In this study, we quantified nutrient allocation to different ecosystem components, including trees, understorey, forest floor, and different soil depths within a chronosequence (6-, 15-, 23-, and 35-year-old) of larch plantations in China. We then assessed the danger of significant nutrient losses from whole tree harvesting (WTH). Nutrient amounts in trees increased with stand age due to an increase in biomass. Stems accounted for 59%–72% of tree biomass and contained 40%–50% of total tree nutrients in the 15- to 35-year-old stands. The forest floor’s nutrient quantities increased from the 6- to 23-year-old stands and then decreased in the 35-year-old plantations. Conversely, most soil indicators initially declined from 15- to 23-year-old stands and then increased in the 35-year-old stand. The total nutrient stocks were greatest in the soil (0–40 cm), which accounted for about 93%–99% of total nutrients in the larch ecosystem. These data indicate that WTH causes nutrient losses about 2.0–2.5 times higher than stem-only harvesting, when thinning 15- or clear-cut harvesting 23- and 35-year-old stands. However, nutrient losses by WTH have little effect on the soil nutrient pools. Prolonging the crop cycle of larch plantations may be beneficial to improve nutrient return through litterfall and allow available soil nutrients to recover.

Multi-objective forestry increases the production of ecosystem services

2020 ◽  
Author(s):  
Olalla Díaz-Yáñez ◽  
Timo Pukkala ◽  
Petteri Packalen ◽  
Manfred J Lexer ◽  
Heli Peltola
Keyword(s):  
Ecosystem Services ◽  
Boreal Forest ◽  
Boreal Forests ◽  
Carbon Balance ◽  
Net Present Value ◽  
Simulation And Optimization ◽  
Multi Objective ◽  
Clear Cut ◽  
Trade Offs ◽  
Continuous Cover Forestry

Abstract Boreal forests produce multiple ecosystem services for the society. Their trade-offs determine whether they should be produced simultaneously or whether it is preferable to assign separate areas to different ecosystem services. We use simulation and optimization to analyse the correlations, trade-offs and production levels of several ecosystem services in single- and multi-objective forestry over 100 years in a boreal forest landscape. The case study area covers 3600 ha of boreal forest, consisting of 3365 stands. The ecosystem services and their indicators (in parentheses) considered are carbon sequestration (forestry carbon balance), biodiversity (amount of deadwood and broadleaf volume), economic profitability of forestry (net present value of timber production) and timber supply to forest industry (volume of harvested timber). The treatment alternatives simulated for each of the stands include both even-aged rotation forestry (thinning from above with clear cut) and continuous cover forestry regimes (thinning from above with no clear cut). First, we develop 200 Pareto optimal plans by maximizing multi-attribute utility functions using random weights for the ecosystem service indicators. Second, we compare the average level of ecosystem services in single- and multi-objective forestry. Based on our findings, forestry carbon balance and the amount of deadwood correlate positively with each other, and both of them correlate negatively with harvested timber volume and economic profitability of forestry. Despite this, the simultaneous maximization of multiple objectives increased the overall production levels of several ecosystem services, which suggests that the management of boreal forests should be multi-objective to sustain the simultaneous provision of timber and other ecosystem services.

Forest floor microarthropod abundance and oribatid mite (Acari: Oribatida) composition following partial and clear-cut harvesting in the mixedwood boreal forest

2004 ◽  
Vol 34 (5) ◽  
pp. 998-1006 ◽  
Author(s):  
Zoë Lindo ◽  
Suzanne Visser
Keyword(s):  
Boreal Forest ◽  
Community Composition ◽  
Relative Abundance ◽  
Forest Floor ◽  
Oribatid Mite ◽  
Diversity Indices ◽  
Mite Species ◽  
Oribatid Mites ◽  
Clear Cut ◽  
Mixedwood Boreal Forest

The effects of partial and clear-cut harvesting on abundance and community composition of forest floor microarthropods and oribatid mites were investigated in conifer and deciduous stands of the mixedwood boreal forest. Soil samples from clearcuts, strip-cut corridors in a partial cut, green-tree retention patches in a partial cut, and uncut control sites were collected 2.5 years after harvest and microarthropods were extracted, enumerated, and identified. Densities of microarthropod suborders were lower in the strip-cut corridors of the deciduous stands and significantly lower in the suborder Oribatida (oribatid mites). Changes in microarthropod community composition, decreased relative abundance of prostigmatid mites, and increased relative abundance of mesostigmatid mites were observed in corridor and clear-cut treatments. Lowered abundances and changes in community composition are likely due to compaction of the forest floor during harvesting. Selected oribatid mite species showed significantly lower abundances in clearcuts than in uncut sites, but diversity indices for oribatid mites were generally not significantly different between uncut sites and clearcuts. Changes in oribatid mite communities following harvesting were thus more quantitative (absolute abundance) than qualitative (diversity, composition), and as a result, use of oribatid mites as biological indicators of disturbance is limited because of the lack of changes in species composition.

Wind-throw mortality in the southern boreal forest: effects of species, diameter and stand age

2007 ◽  
Vol 95 (6) ◽  
pp. 1261-1273 ◽  
Author(s):  
ROY L. RICH ◽  
LEE E. FRELICH ◽  
PETER B. REICH
Keyword(s):  
Boreal Forest ◽  
Stand Age ◽  
Wind Throw

scholarly journals Biological activity, nitrogen dynamics, and chemical characteristics of forest soils in the Šumava national park

2012 ◽  
Vol 49 (No. 7) ◽  
pp. 302-312 ◽  
Author(s):  
M. Svoboda
Keyword(s):  
Forest Soils ◽  
National Park ◽  
Large Scale ◽  
Ground Vegetation ◽  
Mountain Forest ◽  
Respiration Activity ◽  
Forest Sites ◽  
Tree Layer ◽  
Spruce Stands ◽  
Microclimatic Conditions

This paper deals with large-scale mountain forest decline in the Šumava National Park. The changes in biotic and abiotic properties of forest sites follow the tree layer disintegration. Changed microclimatic conditions such as intensity of irradiance, moisture and temperature of the top holorganic layers together with altered development of ground vegetation could strongly affect the values of microbiological respiration activity and the rates of nitrogen mineralization and nitrification. Soil substrates, built of organic mater, located on stony locations, are endangered by introskeletal erosion. This paper compares these features in pairs of research plots, consisting of dead or cut forest and of living stand. According to the results of this study, higher rates of organic matter decomposition, transformed dynamics of nitrogen and other nutrients and possible nutrient leaching from soil solutions were demonstrated in the forest floor under declined spruce stands. The extent and seriousness of these adverse processes for forest soils are strongly site dependent.

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