Method for restoring high-mountain ecosystems in man-damaged areas of stanovoy highlands

Abstract

FIELD: agriculture; reclamation.SUBSTANCE: method which includes site planning, preparation of the soil and vegetation layer, and the transfer of clumps of moss and lichen cushions with the participation of golden rhododendron. Leveling of the site depressions is carried out in compliance with the natural slope of the terrain, not exceeding 10°. The depressions are filled with rocky soil measuring from 10 to 60 cm and a soil-peat mixture with a moss-lichen cover with the participation of golden rhododendron is applied from the previously removed soil-vegetation layer. The clumps, together with accompanying plants, are placed in a moss-lichen cushion according to a pattern of 1.5-2.0 m in a row and between rows. Each clump is sprinkled with a crushed stone and gravel mixture measuring 2-4 cm and watered with 10 liters of water per clump. When replanting clumps of moss-lichen cushions, local plant species adapted to the harsh climatic conditions of the Stanovoy Highlands are used. The period from excavation to planting of clumps of moss-lichen cover, including golden rhododendron, does not exceed 24 hours. No maintenance work is required for the recovering ecosystem; the transplanted plants and their seeds form a high-mountain community close to the zonal type.EFFECT: method ensures acceleration of the process of overgrowing disturbed lands, preservation of species diversity in restored successions, similarity of the community with the zonal type of vegetation, and preservation of the habitat-forming species Rhododendron aureum.1 cl, 1 tbl

Description

[0001] The invention relates to a method for restoring man-made ecosystems in the northern mountain-taiga zone in high-altitude conditions in areas of the subalpine sparse forests of Eastern Siberia, specifically to restoring the biological diversity of plant communities and the productivity of disturbed lands. It aims to preserve the habitat-forming species, golden rhododendron (Rhododendron aureum) [Resolution, 2018], and improve environmental conditions.

[0002] A method for restoring plant communities previously destroyed by mining operations is known [RU Patent No. 2682040, published March 10, 2012]. It can be used in the biological reclamation of overburden waste dumps, particularly for the restoration of steppe communities. This ensures the formation of a self-sustaining steppe, similar to zonal steppe vegetation in terms of floristic composition, productivity, and weed resistance.

[0003] The closest analogue (prototype) of the claimed invention is a method for restoring ecosystems in man-made disturbed areas, including the preparation of a substrate, planting trees and shrubs [Patent RU No. 2343692, published 01 / 20 / 2006], related to a comprehensive technology for restoring man-made disturbed lands in the north of the taiga zone of Russia, in particular to the restoration of the productivity and economic value of forest ecosystems.

[0004] The economic specialization of the Zabaikalsky Krai is mineral resource production, and as a result, the region has a high level of degraded land. Approximately 80% of degraded land is associated with mineral deposit development. The majority of this land is comprised of waste dumps and tailings ponds (in ore mining, these account for 62% to 75% of the land allotment) [Chaplygin, 2009].

[0005] The Udokan copper deposit, the largest in the country and the third-largest in the world in terms of reserves (approximately 24.6 million tons), is located in the Stanovoye Highlands (Udokan Range, Transbaikal Krai). Construction of the Udokan Mining and Metallurgical Plant (MMP), with a combined first- and second-stage capacity of approximately 50 million tons of ore per year, is ongoing; its operational life is 70 years. Design capacity is scheduled to be reached by 2028. Consequently, significant areas are being or will be disturbed by the development of this deposit. Anticipating this, we have developed a method to accelerate ecosystem restoration during the reclamation of disturbed lands after development is complete.

[0006] It is an undeniable fact that the rate of anthropogenic change in the environment significantly exceeds the rate of restoration of ecological balance [Chemura, 2020], which necessitates the search for ways to accelerate the restoration of disturbed communities, to restore their environment-forming and environment-protecting functions and stabilize land erosion processes [Ignatyeva, 2020].

[0007] The Stanovoye Highlands are characterized by harsh climatic conditions: the average annual air temperature is -7.7°C; below-freezing temperatures are recorded for 7-8 months, and the sum of temperatures above 10°C ranges from 640°C in the mountains to 1210°C in large basins. Average annual precipitation ranges from 400 mm per year in the lowlands to a maximum of 850 mm in the highlands, characterizing the region as a cold and humid habitat.

[0008] The altitudinal zonation is represented by mountain-taiga, subalpine shrub, tundra, and alpine belts. Our research is concentrated within the subalpine belt of the Udokan Ridge, where a lower larch-sparse forest subbelt and an upper cedar-dwarf pine subbelt with yernik and a sparse grass-dwarf shrub-lichen layer are distinguished. Above this, yernik-dwarf shrub-lichen tundra predominates. Most phytocenoses of the subalpine belt are characterized by the presence of golden rhododendron [Zhelibo, 2023]. The subalpine belt is characterized by peat-lithozems or podburs, which are characterized by thin thickness, fragmentation, and extremely low humus content (tenths of a percent). A decrease in soil thickness and an increase in soil skeletonization are observed with increasing elevation. Permafrost is widespread in the region, significantly affecting soil formation processes and vegetation distribution.These natural conditions complicate the restoration of both individual elements of the natural complex and the ecosystem as a whole. Additional measures are needed to foster restorative successions.

[0009] According to GOST 17.4.3.02-85, soil restoration after disturbances during excavation work requires preliminary removal of the fertile or potentially fertile layer, its storage and subsequent application to the disturbed area [GOST, 1985]. In the conditions of subalpine highlands, due to the absence or insignificant thickness, fragmentation, and rockiness of the soil horizon, removal of a thin fertile layer is often not provided. At the same time, to carry out restoration work, it is advisable to remove the lichen-peat-moss layer, even if it does not comply with GOST 17.5.3.05-84, in any quantities that can be removed [GOST, 1984].

[0010] The objective of the restoration method is to accelerate the regeneration of disturbed lands; preserve the area's biodiversity; and, most importantly, conserve the habitat-forming species, golden rhododendron (Rhododendron aureum Georgi), which is the dominant or codominant shrub layer in the Stanovoye Highlands of Eastern Siberia. The ultimate goal is to create a nature-like community close to the zonal type in vegetation composition. This objective is relevant because the region has a significant number of large deposits, the development of which has begun or is planned for the coming years, which will inevitably lead to significant areal disturbance of high-mountain ecosystems. High-mountain ecosystems play an important role in maintaining biological diversity, ecological balance, and ensuring the sustainable development of Russia's mountainous regions.Complex natural and climatic conditions create additional difficulties for vegetation restoration, requiring special reclamation methods and a differentiated approach for different altitude conditions.

[0011] The restoration method is based on site planning, preparation of the topsoil, relocation of clumps of trees with a moss-lichen cushion containing golden rhododendron, leveling of depressions in the site, filling of depressions with rock, placement of clumps according to a plan, covering them with crushed stone and gravel, and watering with 10 liters per clump. The inclusion of native species increases the resilience of restored ecosystems to adverse environmental factors, and their seeds ensure the formation of a high-mountain community similar to the zonal type. This relocation is best carried out in late summer to mid-September. This timing is explained by the fact that during this period, humid and cool weather sets in, which is favorable for plant establishment. Replanting is performed only when the vegetation process has slowed.

[0012] To establish golden rhododendron, it is important to create conditions in which the substrate contains mycorrhiza, which allows plants to grow and develop in a thin, poor soil layer on relatively poor soils, increasing the root system's absorption surface. Furthermore, mycorrhizal fungi increase plant stress resistance [Volodko, Rupasova, Titok, 2015]. A mixture consisting of peat and moss-lichen litter seems to us to be the most successful solution. Furthermore, other species of vascular plants can be introduced along with the clumps.

[0013] The restoration site must be prepared and have similar characteristics (altitude above sea level, aspect and steepness of slopes, soil acidity) to the site from which the species will be removed. In the restoration (reintroduction) site, it is necessary to level the depressions of the site with rocky soil with a size of 10 to 60 cm, maintaining a slope not exceeding 10°. It is necessary to create conditions that do not allow stagnant water. Continuous application of a soil-peat mixture from the removed soil and vegetable layer (SVL) to a thickness of at least 12 cm, at a rate of 300 t / ha. Its compaction should be avoided. Prepare planting sites measuring 50 × 50 cm. Planting is carried out according to the following placement pattern: the distance between rows is 1.5–2.5 m, the planting step within a row is 1.5–2.0 m.

[0014] In the first stage of the work, clumps of golden rhododendron, ranging in size from 30x30 cm to 60x60 cm, are manually removed from the soil-vegetation or moss-lichen layer. They are placed in polyethylene bags and sealed. This procedure helps reduce transpiration. The removal is done carefully, avoiding damage to the bush shoots, and then packed in rigid shipping containers. Each container holds 2 to 5 clumps of plants, depending on their size. The containers with the clumps are evenly distributed in the back of the vehicle and transported to the planting site. It is important to consider the number of plants being transplanted; the plants must be removed and transplanted within 24 hours. The delivered clumps are placed in pre-prepared holes, the depth of which corresponds to the height of the clumps. At this stage, particular attention should be paid to the placement of the above-ground and underground parts.To prevent root sagging, apply a 2–4 ​​cm layer of crushed stone and gravel mixture to the transplanted clumps. Regardless of weather conditions, water the clumps with 10 liters of water. When transplanting, it's important to ensure the time from digging to planting doesn't exceed 24 hours.

[0015] The application of the proposed set of measures ensures the following technical result:

[0016] – accelerated timeframe for the process of overgrowing disturbed lands;

[0017] – conservation of species diversity in restored successions;

[0018] – similarity of the community with the zonal type of vegetation;

[0019] – preservation of the habitat-forming species Rhododendron aureum.

[0020] Practical work on restoring disturbed lands has demonstrated the high effectiveness of this technology, which allows for the organization of comprehensive work and the rapid initiation of the process of restoring disturbed ecosystems.

[0021] In August 2019, a batch of 320 specimens was reintroduced to a disturbed 3-hectare subalpine forest in the Kalarsky District of the Zabaikalsky Krai. A second batch of 640 specimens was reintroduced in August 2020. The total number of golden rhododendron specimens reached 960.

[0022] The following works were carried out during the seizure process:

[0023] 1) Mechanical pruning of the soil-vegetation layer (MPS). The MPS included the above-ground and underground parts of the golden rhododendron, as the plant's root system in this area is distributed within a moss-lichen clump. The removal and reintroduction sites had similar physical and geographical characteristics, such as elevation, slope aspect and steepness, and soil parameters.

[0024] 2) Removing clumps of golden rhododendron specimens for transportation. Specimens were removed manually from a pre-cut layer, along with their moss-lichen cushion. Their condition and parameters were assessed during removal. The average size of the clumps with their moss-lichen cushion ranged from 30×30 cm to 60×60 cm. Removal was carried out carefully, avoiding damage from broken shoots.

[0025] 3) The clumps were packed into polyethylene bags (large ones, at least 90x130 cm), 2 to 5 clumps per bag, depending on their size, and divided into batches. The batches were then labeled and placed in rigid containers. On the same day, all packaged plants were transported to the site prepared for transplantation. They were transported by truck in polyethylene bags placed in rigid containers.

[0026] The process of technological reclamation of the site included several types of work: leveling the site while maintaining the natural slope of the terrain, not exceeding 10°; filling the depression (quarry) with rocky soil ranging in size from 10 to 60 cm; applying a soil-peat mixture with a moss-lichen cover from previously removed PRS, from neighboring areas.

[0027] The prepared area was marked for planting moss-lichen clumps, including golden rhododendron. Rows were planted with a spacing of 1.5 and 2.0 m, spaced evenly within a row at 1.5 m, 4 rows at 2.0 m spacing, and staggered placement. One row was solid planting, with clumps placed close together. A total of 320 specimens were transplanted, arranged in 16 rows. The transplantation was carried out using the transshipment method. The clump and accompanying plants were placed in a moss-lichen cushion in planting holes and covered with the surrounding soil and vegetation layer. Subsequently, to prevent the roots from hanging, the clump was covered with a 2–4 ​​cm crushed stone and gravel mixture. Planting was accompanied by watering – 10 liters per clump.

[0028] The second stage of replanting was carried out using a similar technique. In August 2020, 640 moss-lichen clumps of golden rhododendron were planted in 12 rows, with a distance of 1.5 m between rows and 1.5–2.0 m between clumps.

[0029] No maintenance work was carried out at the restoration site.

[0030] Particular attention is paid to monitoring the condition of the restored ecosystem for several years after the work is completed. Regular monitoring includes assessing species composition, projective cover, and abundance, as well as measuring key indicators of the survival and health of golden rhododendron. The total area of ​​the site where clumps were planted was 1.9 hectares; the remaining area (1.1 hectares) was left unplanted and allowed to grow naturally.

[0031] A comparative study of revegetation within and beyond restoration sites allowed us to assess restoration processes. The dynamics of vegetation restoration are presented in Table 1.

[0032] Table 1 – Comparative characteristics of overgrowing areas

[0033] Year of observation Recovery area Area of ​​spontaneous overgrowth Number of types, pieces Total projective cover, % Number of types, pieces Total projective cover, % 2020 14 3 0 0 2021 23 7 1 3 2022 27 14 2 4 2023 39 80 4 8 2024 39 85 6 16

[0034] In the first year, reforestation begins in waterlogged areas in the microrelief depressions. Bypassing successions dominated by bryophytes, successions involving grasses are formed. After four years, small-leaved tree species appear in the vegetation, forming patches of willow and birch groves. Subsequent years are characterized by changes in the projective cover of existing species and the addition of coniferous tree species (Gmelin's larch) and shrub species (dwarf pine).

[0035] Vegetation development outside the plantings, in the spontaneously overgrown area, follows a different pattern. Bryophytes were among the first to colonize the disturbed area. After two years of observation, the vegetation is represented by two bryophyte species. The third and fourth years are characterized by the appearance of single grass species, horizontally distributed randomly, without significant clusters. No pattern of distribution is observed. Species diversity remains sparse and significantly differs from the abundance and projective cover of the restoration area.

[0036] According to monitoring results, the survival rate of golden rhododendron was 93.6%. The total projective cover of the restoration site after 4 years was 5.3 times higher, and the total number of plant species was 6.5 times greater.

[0037] The following species of vascular plants were transplanted into the moss-lichen clump: common blueberry (Vaccinium uliginоsum L.), shrub birch (Betula fruticosa Pall.), spreading birch (Betula divaricata Ledeb.), common lingonberry (Vaccinium vitis-idаеа L.), small-fruited cranberry (Oxycoccus

[0038] microcarpus Turcz. ex Rupr.), marsh wild rosemary (Ledum palustre L.), brown sedge (Carex brunnescens (Pers.) Poir. in Lam.), wrinkled mnium (Mnium rugicum Laur.), Schreber's pleurosis (Pleurozium schreberi (Brid.) Mitt.), wrinkled rhytidium (Rhytidium rugosum (Hedw.) Kindb).

[0039] Overall, four main plant groups inhabit the disturbed area: bryophytes; grasses and sedges, small-leaved woody plants; and coniferous trees and shrubs. During the study period, the composition of the plant community shifted, with an increase in sedges and grasses. Forbs include fireweed (Chamaenerion angustifolium (L.) Scop.) and alpine ram (Aconogonon alpinum (All.) Schur).

[0040] There was a change in the share of projective cover of such species as Dahurian larch (Larix gmelinii (Rupr.) Rupr.), curved kidney willow (Salix recurvigemmis A.K. Skvortsov), Schwerin willow (Salix schwerinii E.L. Wolf), shrub birch (Betula fruticose), spreading birch (Betula divaricate), shrub alder (Duschekia fruticose (Rupr.) Pouzar), dwarf pine (Pinus pumila (Pall.) Regel), common blueberry (Vaccinium uliginosum), reddish wood-sedge (Luzula rufescens Fisch. ex E. Mey.).

[0041] Using this technology allows for accelerated restoration of key ecosystem components, primarily vegetation, and increased diversity. The restoration process follows an accelerated schedule: Stage 1 – restoration of herbaceous vegetation; Stage 2 – restoration of herbaceous and deciduous woody vegetation; Stage 3 – formation of coniferous woody vegetation. The habitat-forming species Rhododendron aureum is preserved.

[0042] No maintenance is provided for the recovering ecosystem.

[0043] This method can be used in any area with destroyed natural vegetation during the reclamation of industrial roads, man-made and other “waste” lands.

Claims

A method for restoring high-mountain ecosystems in technogenically disturbed areas of the Stanovoye Highlands, including terrain planning, preparation of the soil and vegetation layer, transfer of clumps with a moss-lichen cushion with the participation of golden rhododendron, characterized in that the leveling of depressions of the site is carried out in compliance with the natural slope of the terrain, not exceeding 10 °, filling the depressions with rocky soil with a size of 10 to 60 cm and applying a soil-peat mixture with a moss-lichen cover with the participation of golden rhododendron from the previously removed soil and vegetation layer, clumps together with accompanying plants in a moss-lichen cushion are placed according to a pattern of 1.5-2.0 m in a row and between rows, each clump is sprinkled with a crushed stone-gravel mixture with a size of 2-4 cm, watered with 10 liters per clump, when transplanting The moss-lichen cushion clumps use local plant species adapted to the harsh climatic conditions of the Stanovoye Highlands,The period from digging to planting clumps of moss-lichen cover with the participation of golden rhododendron does not exceed 24 hours, maintenance work for the recovering ecosystem is not provided, the transplanted plants and their seeds form a high-mountain community close to the zonal type.