Effect of tree species mixing on the size structure, density, and yield of forest stands

2015 ◽  
Vol 135 (1) ◽  
pp. 1-22 ◽  
Author(s):  
Hans Pretzsch ◽  
Gerhard Schütze
Keyword(s):  
Tree Species ◽  
Size Structure ◽  
Forest Stands ◽  
Structure Density

scholarly journals Over half of western United States' most abundant tree species in decline

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hunter Stanke ◽  
Andrew O. Finley ◽  
Grant M. Domke ◽  
Aaron S. Weed ◽  
David W. MacFarlane
Keyword(s):  
United States ◽  
Tree Species ◽  
Tree Mortality ◽  
Temperate Forests ◽  
Size Structure ◽  
Forest Disturbance ◽  
Population Decline ◽  
Western United States ◽  
Scale Transformation ◽  
Forest Composition

AbstractChanging forest disturbance regimes and climate are driving accelerated tree mortality across temperate forests. However, it remains unknown if elevated mortality has induced decline of tree populations and the ecological, economic, and social benefits they provide. Here, we develop a standardized forest demographic index and use it to quantify trends in tree population dynamics over the last two decades in the western United States. The rate and pattern of change we observe across species and tree size-distributions is alarming and often undesirable. We observe significant population decline in a majority of species examined, show decline was particularly severe, albeit size-dependent, among subalpine tree species, and provide evidence of widespread shifts in the size-structure of montane forests. Our findings offer a stark warning of changing forest composition and structure across the western US, and suggest that sustained anthropogenic and natural stress will likely result in broad-scale transformation of temperate forests globally.

FEATURES OF THE WATER REGIME IN THE CHERNOZEM UNDER THE STANDS OF POPLAR BIRCH AND ITS REGULATION

2020 ◽  
pp. 58-63
Author(s):  
S.V. Makarychev ◽  
Keyword(s):  
Tree Species ◽  
Water Regime ◽  
Growing Season ◽  
Forest Stands ◽  
Ecological Balance

Forest stands of the arboretum contribute to the preservation of ecological balance on the territory of Barnaul. It contains a large number of tree species, one of which is poplar birch (Betulapopulifolia). The article shows that over the years of research, the water regime in the Chernozem profile under birch stands remains tense for most of the growing season, so there is a need to use irrigation with different irrigation standards, depending on the emerging hydrological state.

scholarly journals Selection of the assortment of trees for protective forest plantations

2020 ◽  
Author(s):  
A.I. Petelko ◽  
Keyword(s):  
Species Composition ◽  
Tree Species ◽  
Effective Means ◽  
Water Erosion ◽  
Current Status ◽  
Forest Plantations ◽  
Forest Stands ◽  
Protective Forest ◽  
Selection Of ◽  
Hydrographic Network

Reclamation of land on community land funds and the hydrographic network contributes to the most effective means of protecting the soil from water erosion. However, the condition, growth, and productivity of the protective forest stands themselves depend on the species composition. Many years of studies have clearly shown that not all tree species and shrubs can successfully grow on washed soils. Extensive scientific material provides a description of the growth and current status of the studied species, a detailed taxation description of the forest plantations. Of particular value are those species that can grow on eroded lands and protect the soil from erosion.

scholarly journals Tree shape and form in ancient coppice woodlands

2017 ◽  
Vol 10 (2) ◽  
pp. 49-62 ◽  
Author(s):  
Petr Maděra ◽  
Tomáš Slach ◽  
Luboš Úradníček ◽  
Jan Lacina ◽  
Linda Černušáková ◽  
...  
Keyword(s):  
Tree Species ◽  
Field Survey ◽  
Scientific Literature ◽  
Forest Stands ◽  
Tree Shape ◽  
Lack Of Information ◽  
Basic Features

Abstract Ancient coppice woodlands are coppice-originated forest stands with a long-term continual development, and with the preserved typical natural and historic elements of old sprout forests. Prominent natural elements in the ancient coppice woodlands are namely old coppice stools. There is, in scientific literature, lack of information about features of ancient coppice stools. Therefore, our contribution aims to describe shape and form of ancient coppice stools, including the most important microhabitat of coppice woodlands – dendrothelms. Based on field survey of 20 localities of important coppice woodlands we recorded 135 ancient coppice stools of 13 tree species and a total of 80 dendrothelms in 9 tree species. Basic features of ancient coppice stools and dendrothlems were measured and evaluated.

scholarly journals Site Type Effect on Litter Decomposition Rates: A Three-Year Comparison of Decomposition Process between Spoil Heap and Forest Sites

Forests ◽  
2019 ◽  
Vol 10 (4) ◽  
pp. 353 ◽  
Author(s):  
Horodecki ◽  
Jagodziński
Keyword(s):  
Litter Decomposition ◽  
Tree Species ◽  
Ex Situ ◽  
Soil Conditions ◽  
Forest Stands ◽  
Decomposition Rates ◽  
Degraded Lands ◽  
Spoil Heap ◽  
Forest Sites ◽  
Pine Stands

Research Highlights: Direct comparison of leaf litter decomposition rates between harsh soil conditions of degraded lands and adjacent “closer to natural” forest areas has not been done before. Background and Objectives: We aimed to fill this knowledge gap by determining the differences in amounts of carbon and nitrogen released by species-specific litter depending on decomposition rates in various stand and habitat conditions, which enables selection of the most ecologically and economically appropriate (for fast soil organic layer development) tree species for afforestation of reclaimed lands. Materials and Methods: The study was conducted on the external spoil heap of the “Bełchatów” lignite mine (Central Poland) and adjacent forests. In December 2013, we established a litterbag experiment beneath the canopies of birch and pine stands. We used litter of Alnus glutinosa (Gaertn.), Betula pendula (Roth), Pinus sylvestris (L.), and Quercus robur (L.) collected ex situ, which we installed (after oven-drying) beneath the canopies of eight stands. The experiment lasted for three years (with sampling of three-month intervals). Results: Harsh soil conditions of degraded lands are unfavorable for litter mineralization. It was found that 23%–74% of decomposed materials were mineralized in spoil heap stands, whereas in forest stands these amounts ranged from 35%–83%. Litter of Q. robur in birch stands on the spoil heap is predicted to take 12 years longer for total decomposition than in forest stands of the same species. This hinders organic carbon turnover and could result in elongation of the time for full biological and economic reclamation of degraded lands. On the other hand, decomposition of relatively fast decomposable litter (A. glutinosa and B. pendula) in pine stands on the spoil heap was faster than in pine stands in forest sites (17% and 13% faster, respectively). We did not observe this trend for decomposition of more recalcitrant litter types of P. sylvestris and Q. robur. Conclusions: The results show the value of selective choice of tree species for afforestation of post-mining areas to accelerate the development of technogenic soil substrates. We recommend introducing all tree species studied in the cluster form of admixtures as all of them could bring some profits in ecological and economical reclamation.

scholarly journals Harvester Productivity in Inclined Terrain with Extended Machine Operating Trail Intervals: A German Case Study Comparison of Standing and Bunched Trees

2020 ◽  
Vol 12 (21) ◽  
pp. 9168
Author(s):  
Ferréol Berendt ◽  
Eduardo Tolosana ◽  
Stephan Hoffmann ◽  
Paula Alonso ◽  
Janine Schweier
Keyword(s):  
Tree Species ◽  
Timber Harvesting ◽  
Forest Stands ◽  
Operational Conditions ◽  
Thinning Operation ◽  
Standing Trees ◽  
Broadleaved Tree Species ◽  
Broadleaved Tree ◽  
Multiple Tree

The complexity of highly structured forests with multiple tree species, especially when coniferous and broadleaved tree species are mixed, as well as stands with extended machine operating trail spacing and inclined terrain, create challenging operational conditions for mechanized timber harvesting and extraction. Motor-manually felling trees within the midfield and bunching them at the machine operating trails, prior to the arrival of a harvester-forwarder system, is a complex operation. The aim of this study was to assess and compare tethered harvester productivities of a thinning operation, for felling and processing standing trees and for processing bunched trees, through a time study in forest stands with 40-m distances between machine operating trails. Total operational costs of the analyzed thinning operation were 69 €/m3o.b., including extraction using a multiple forwarder approach. Tree species, merchantable timber volume, and whether the trees were standing or presented as bunched logs all had a significant effect on the harvester time consumption. Moreover, harvester positioning time was significantly shorter when trees were already bunched at the machine operating trail. While the productivity of standing or bunched spruce trees did not differ significantly between the cases (approximately 18 m3o.b./productive machine hours excluding all delays (PMH0)), the productivity of standing broadleaved tree species (8.3 m3o.b./PMH0) was much lower than that of bunched trees (15.5 m3o.b./PMH0). Thus, the described timber harvesting and extraction system may be a valuable option for forest stands with high proportion of broadleaved trees.

scholarly journals Structure and development of forest stands on permanent research plots in the Krkonoše Mts.

2010 ◽  
Vol 56 (No. 11) ◽  
pp. 518-530
Author(s):  
S. Vacek ◽  
Z. Vacek ◽  
L. Bílek ◽  
I. Nosková ◽  
O. Schwarz
Keyword(s):  
Species Composition ◽  
Tree Species ◽  
Vertical Structure ◽  
Forest Stand ◽  
Forest Stands ◽  
Vegetation Zone ◽  
Aggregation Index ◽  
Tree Species Composition ◽  
Results Management ◽  
Management Recommendations

The research is focused on structure and development of forest stands from 5th to 8th forest vegetation zone in the Krkonoše Mts. The forest stand diversity according to tree species composition and representation, horizontal and vertical structure was evaluated by using following indices: Clark-Evans aggregation index (Clark, Evans 1954), standardised Arten-profil index (Pretsch 2005) and index of complex diversity after Jaehne, Dohrenbusch (1997). Growth model SIBYLA (Fabrika, Ďurský 2005) was used for visualizations and growth predictions of forest stands on particular plots. Based on research results, management recommendations were evaluated.

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