Do we need care thinning in young pine stands in their typical habitats?

Thinning is the main activity in the system of sustainable forest management. They define target indicators, which will have forest stands by the final cuttings. Scots pine Pinus sylvestris L. is the most widespread of economically valuable species. The aim of the work was an experimental verification of the probability of a species succession in typical pine habitats of the southern taiga of Western Siberia. The experimental area is located in the Timiryazevskiy forestry unit of the Tomsk Oblast, where green-mossy pine forests were cut down in 1999–2001. In 2010, thinning was carried out on young stands on an area of about 45 hectares. The thinning was carried out with a cutting of unwanted trees with strips of 5 m wide, i. e. cutting intensity was 50 %. As a result of studies, it was found that in the control plots, mixed stands with a share of scots pine about 40 % were formed. Aspen predominates in the stand composition, which is almost completely affected by rot of the trunk (90–100 %). Scots pine is much behind growth in aspen (2 times). The radial growth of trunk also indicates the suppression of the Scots pine. The two tier of stands is formed in the strip with thinning, where the upper tier is occupied by Scots pine, and the subordinate is aspen. The important stage in the creation of a new forest generation is the settlement dynamics of the felling area. For Scots pine, the pulsed nature of regeneration is confirmed – over a short period of time (3–4 years). Deciduous trees have a longer reforestation period (6–7 years). The increase in height in the strip with thinning turned out to be significantly higher than in the control plots (40–50 cm versus 20–30 cm). The developed system of felling, which consists in carrying out the first intake of non-commercial thinning at the age of 6–7 years old Scots pine and the second intake of thinning at 10–11 years, ensures the formation of Scots pine young stands

The Siberian Stone Pine Stands Near Settlements in Tomsk Region. Problems of Sustainable Forest Use

A review of the Siberian stone pine stands' formation near settlements in Tomsk region is given in historical aspect. Their current status is described in detail. Age, tree species, and typological structure, as well as productivity and dynamics of forest inventory indices have been identified. Forest management practices in leased and non-leased Siberian stone pine stands have been analyzed. The ways and procedures for an expansion of the existing Siberian stone pine stands and creation of new Siberian stone pine forests near settlements is proposed

The examples of forest management in secondary forests of Western Siberia

Identifying the best practices of responsible and sustainable forest use is an important aspect for possible learning of experience and replication of the most interesting examples in forestry. Qualitative and timely reforestation of disturbed areas with economically valuable species is the key indicator for the performance of effective forest management. Conservation of rare species of plants and animals in the logged areas is not less important factor. Today the priority is given to natural forest regeneration because it provides the best opportunity to avoid unreasonable financial costs and, as a rule, is more resilient against various natural and anthropogenic factors. The article discusses various examples and logging types in secondary forests in the Tomsk and Omsk Oblast, which allow increasing the economic, environmental, and social importance of forests. On specific examples it is shown that the principle of non-interference in the green zones of settlements is erroneous and may lead to undesirable consequences. The rejection of logging in these stands, as a rule, leads to increases of the fire danger, growth of phyto- and entomological threats, the reduction of recreational appeal, etc. The use of partial logging methods suggested in the papers has allowed solving some of these problems

Formation of Siberian pine forests by improvement felling on former agricultural lands

On the base of the researches carried out on the permanent study area silvicultural effectiveness of improvement felling was analyzed in soft-leaved plantations formed on the former agricultural lands in Khanty-Mansi Autonomons Okrug - Yugra. It was experimentally found that among 25-30-year-old soft-leaved stands there is Siberian pine (Pinus sibirica Du Tour); besides this, nominal undergrowth of this species can be found under the canopy. Improvement felling can provide an increase in the share of Siberian pine in the composition of the forming plantations and even its dominance in stands. It is recommended to carry out improvement felling by the strip method. On the first-stage the felling of soft-leaved species in strips of 10 m wide is carried out, while leaving strips of similar width without care. On the second stage in 10 years soft-leaved trees are cut down in those strips where care was not taken. Felling of all the accompanying Siberian pine trees in a single shot is inadmissible, since it leads to intensive growth of herbaceous vegetation, sodding and exclusion of the Siberian pine undergrowth as well as dramatically increases the fire danger in spring and autumn. In addition, at the indicated intensity, the specimens of Siberian pine left for cultivation are affected by Pineus cembrae (Cholodovsky, 1988).По материалам исследований, выполненных на постоянной пробной площади, проанализирована лесоводственным методом эффективность рубок ухода в мягколиственных насаждениях, сформировавшихся на бывших сельскохозяйственных угодьях в Ханты-Мансийском автономном округе – Югре. Экспериментально установлено, что в составе 25–30-летних мягколиственных насаждений имеет место сосна кедровая сибирская (Pinus sibirica Du Tour.), кроме того, под пологом древостоев присутствует «условный подрост» данной породы. Проведением рубок ухода можно обеспечить увеличение доли сосны кедровой сибирской в составе формирующихся насаждений и даже ее доминирование в древостоях. Рубки ухода рекомендуется проводить полосным способом. При первом приеме производится вырубка деревьев мягколиственных пород в полосах шириной 10 м при оставлении без ухода полос аналогичной ширины, при втором приеме (через 10 лет после первого) деревья мягколиственных пород вырубаются в тех полосах, где ухода не было. Вырубка всех деревьев, сопутствующих сосне кедровой сибирской, за один прием недопустима, поскольку приводит к интенсивному разрастанию травянистой растительности, задернению и исключению появления подроста сосны кедровой сибирской, а также резко повышает пожарную опасность весной и осенью. Кроме того, при указанной интенсивности оставляемые для выращивания экземпляры сосны кедровой сибирской поражаются хермесом сибирским (Pineus cembrae Cholodkovsky, 1988)

Zhang-Rice physics and anomalous copper states in A-site ordered perovskites

In low dimensional cuprates several interesting phenomena, including high T(c) superconductivity, are deeply connected to electron correlations on Cu and the presence of the Zhang-Rice (ZR) singlet state. Here, we report on direct spectroscopic observation of the ZR state responsible for the low-energy physical properties in two isostructural A-site ordered cuprate perovskites, CaCu(3)Co(4)O(12) and CaCu(3)Cr(4)O(12) as revealed by resonant soft x-ray absorption spectroscopy on the Cu L(3,2)- and O K-edges. These measurements reveal the signature of Cu in the high-energy 3+ (3d(8)), the typical 2+ (3d(9)), as well as features of the ZR singlet state (i.e., 3d(9)L, L denotes an oxygen hole). First principles GGA + U calculations affirm that the B-site cation controls the degree of Cu-O hybridization and, thus, the Cu valency. These findings introduce another avenue for the study and manipulation of cuprates, bypassing the complexities inherent to conventional chemical doping (i.e. disorder) that hinder the relevant physics