Comparision of regeneration of scots pine Pinus sylvestris L. in Myrtillosa and Hylocomiosa forest types after shelterwood cuttings

The aim of the study is to determine how successful the initial growth of naturally grown and planted pines is after performing the shelterwood cutting. The research includes tree count and height analysis in Myrtillosa and Hylocomiosa forest types with different regeneration methods in 2018. A total of 10 sites were arranged for the research, each site having 4 sample plots. All naturally regenerated and planted pine (2009, 2012 and 2013) heights were measured. Judging by the number of trees after shelterwood cutting, most sites should not be considered regenerated, additional planting or scarification of soil is required which can improve the efficiency of natural regeneration. In all the sites both in Myrtillosa and Hylocomiosa, after shelterwood cutting it was observed that the height of artificially regenerated trees is higher than the height of naturally regenerated trees, indicating the ability of planted pines to produce more rapid height increment in the first years of life, regardless of forest type. The basal area of the stand has a significant negative impact on the increment, and it indicates the need for the subsequent shelterwood cut to be performed. Although Hylocomiosa is a more fertile forest type than Myrtillosa, the height of the planted pine trees in Myrtillosa is higher than in Hylocomiosa, where, after shelterwood cutting, no sufficiently intensive agro-technical tending has been performed.

Effect of strip shelterwood-cuts on the crown morphology plasticity of natural regenerated Pinus tabuliformis saplings in northeastern China

The study analysed the effect of shelterwood-cut strips on the outermost crown profiles and crown characteristics of naturally regenerated Pinus tabuliformis saplings in northeastern China. A total of 49 regenerated saplings from shelterwood-cut strips and 30 from uncut strips were collected. Nonlinear quantile regression was used to develop the outermost crown profile model for the saplings from the shelterwood-cut and uncut strips. The quantile value suitable for describing the outermost crown profiles of the two types of strips was selected using nonparametric boundary regression. The difference in crown morphologies between the shelterwood-cut strips and uncut strips was compared. The results showed that with the same diameter at breast height, the crown radii of the uncut strip saplings were larger than those of the shelterwood-cut strip saplings within the range of 0.2–1.0 for the relative depth into the crown. The largest crown radius of the saplings from the uncut strips was larger than that of the saplings from the shelterwood-cut strips. The inflection points of the shelterwood-cut strip sapling crowns were larger than those of the uncut strip sapling crowns. The crown volume of the small uncut strip saplings was larger than that of the shelterwood-cut strip saplings, and the difference in crown volume decreased with increasing sapling size. The saplings in the early stage of the uncut strips showed a greater growth rate than those of the shelterwood-cut strips, but their growth rate slowed over the long term according to branch-length annual growth. The present study provides a reference for forest management strategy decision making in promoting natural regeneration.

Productivity and functioning of the beech ecosystem: Ecological Experimental Station – Kremnické vrchy Mts. (Western Carpathians)

At beginning of the 1980‘s, the National Science Foundation (USA) came up with the initiation of the program for Long-Term Ecological Research (LTER), which is a program based on long-term comprehensive study of the structure and processes of ecosystems. The Ecological Experimental Station (EES) in the Kremnické vrchy Mountains (Western Carpathians, Slovakia, 1986) was founded for similar purposes. The aim of the research at EES was to evaluate the productivity, carrying capacity and functioning of the beech ecosystem. In February 1989, five plots were established. Four plots were subjected to a regeneration cutting of different intensities (clear-cut, strip shelterwood cut: light, medium and heavy). The fifth plot was left without any management treatments as a control. The second cutting was performed in 2004 followed by the final cutting five years later. Currently, the research is carried out on the EES control plot in the stand comprising 115–120 years old beech trees. In the other stands the research is focused on the development of naturally regenerated beech ecosystems established after different cutting interventions. The future of the EES is in addressing some global issues, particularly the impact of climate change on primary production, as well as on its other consequences for the functioning of the affected ecosystems.

Do chestnut, northern red, and white oak germinant seedlings respond similarly to light treatments? II. Gas exchange and chlorophyll responses

Understanding differences in physiological and growth strategies in low-light environments among upland oak species may help managers address the challenges of oaks’ poor regeneration. Gas exchange and chlorophyll content were measured for northern red oak ( Quercus rubra L.), chestnut oak ( Quercus prinus L.), and white oak ( Quercus alba L.) germinants grown at 25%, 18%, and 6% of full sun in one of two native forest soil mixes for two summers. Northern red and chestnut oak photosynthesis at saturating light (Amax, mass) increased by 23%–36% as light levels increased from 6% to 25% of full sun, while white oak Amax, mass declined by 20% and plateaued at 18% of full sun. White oak light compensation point is representative of deep shade (7.2 µmol·m–2·s–1), while northern red and chestnut oak averaged 17.8 µmol·m–2·s–1. Total chlorophyll content increased as light levels decreased for all species. Of the three species, the slow-growing white oak seedlings appeared to be more efficient in utilizing light than northern red or chestnut oak seedlings. This suggests no additional benefits to increasing light above that typically found in a light shelterwood cut; however, it is crucial to control faster-growing competing vegetation.

Nutrient cycling in two continuous cover scenarios for forest conversion of pine plantations on sandy soil. II. Nutrient cycling via throughfall deposition and seepage flux

This study examined ion throughfall deposition and seepage fluxes in silver birch (Betula pendula L.) and Scots pine (Pinus sylvestris L.) regenerations a decade after a forest conversion intervention in two continuous cover scenarios (shelterwood cut versus group cut), as well as a 70-year-old control stand of Scots pine. Ion throughfall deposition was significantly influenced by the conversion scenario, being higher in the shelterwood cut than in the group cut. Compared with the control stand, nitrogen and acidifying throughfall deposition was significantly lower (–60%) in all regeneration types except for the birch regeneration under shelter. After shelter removal, ion throughfall deposition was significantly lower in all regeneration types than in the control stand. Seepage of NO3– and SO42– was significantly affected by the tree species, being higher in the birch than the pine regenerations, and SO42– seepage was significantly higher under shelter than in the group cut. After shelter removal, neither tree species nor scenario influenced the SO42– seepage, whereas the tree species still affected NO3– seepage. We conclude that the chosen forest conversion scenario is of profound influence on the ion throughfall and seepage fluxes during the first phase of a forest conversion process.

First-year impacts of shelterwood logging on understory vegetation in an old-growth pine stand in central Ontario, Canada

There is evidence in the literature that a variety of logging practices may result in significant short and long-term changes to vegetation in the forest understory, however, these changes are still largely unknown for many forest types. The objective of this study was to determine the short-term effects of shelterwood logging on tree and non-arboreal plant species composition and diversity in both the understory and sapling strata within the Owain Lake Stand of old-growth red and eastern white pine located in Temagami, Ontario. The most significant changes were increases of white birch (800%), red maple (363%) and bracken fern (110%) in the understory. The most significant decreases within the understory occurred in mosses and liverworts (110%), Canada mayflower (49%) and starflower (28%). Bracken fern, red maple, and bush honeysuckle were the three most abundant species in the post-harvest understory plant community and will probably increase in their abundance under the present disturbed condition. A second shelterwood cut in 20 to 40 years may further facilitate an increase in these three species primarily by increasing light levels at the forest floor. All three species are very vigorous and are likely to dominate the forest understory until the upper canopy closes resulting in decreased light intensity at the forest floor.

Antelope Bitterbrush and Scouler's Willow Response to a Shelterwood Harvest and Prescribed Burn in Western Montana

In many western Montana ponderosa pine (Pinus ponderosa) stands, fire suppression and past selective logging of large trees have resulted in conditions favoring succession to dense stands of shade-tolerant, but insect- and disease-prone Douglas-fir (Pseudotsuga menziesii). Stand thinning and understory prescribed burning have been proposed as surrogates for pre-Euro-American settlement ecological processes and as potential treatments to improve declining forest condition and reduce the probability of severe wildfire. To test the effectiveness of these silvicultural techniques on overstory and understory conditions, research is ongoing in the Lick Creek Demonstration Site in the Bitterroot National Forest, Montana. Our research examined the response (mortality and vigor) of the dominant browse species, antelope bitterbrush (Purshia tridentata) and Scouler's willow (Salix scouleriana), to a ponderosa pine stand restoration project utilizing four treatments: (1) a shelterwood cut that removed 53% of the tree basal area; (2) a shelterwood cut with a low fuel consumption burn; (3) a shelterwood cut with a high fuel consumption burn; and (4) a control. Prior to the application of treatments, 1,856 bitterbrush and 871 willow were located, and their survival and vigor subsequently monitored for 2 yr posttreatment. The cut and burn treatments resulted in the greatest reduction in antelope bitterbrush and Scouler's willow density averaging 66% and 24% of pretreatment density, respectively. The shelterwood cut reduced bitterbrush and Scouler's willow density by 35% and 14%, respectively. On treatments receiving a shelterwood cut (all treatments but the control), but where antelope bitterbrush and Scouler's willow did not have fire damage, mortality was 45% for bitterbrush and 20% for willow, respectively. For bitterbrush and Scouler's willow plants that received fire damage, mortality was 72% for bitterbrush and 19% for willow. Although the burn and shelterwood harvest treatments resulted in reduced density of antelope bitterbrush and Scouler's willow 2 yr posttreatment, these treatments increased vigor of both species and created mineral seedbeds that may be necessary for establishment of seedlings. West. J. Appl. For. 14(3):137-143.