Soil and water conservation afforestation

1 planning

1. 1 forest tree species planning

1. 1. 1 The following forest species are arranged according to different uses:

(1) Economic forest. Give priority to the selection of fresh and dried fruits with local characteristics and varieties with market competitiveness.

(2) firewood forest. In areas lacking fuel, the planting area shall be determined according to the amount of firewood per capita and the amount of firewood that trees may provide per hectare.

(3) feed forest. In the arid and semi-arid areas of northern China, shrub feed forests such as Robinia pseudoacacia and Amorpha fruticosa can be built in combination with soil and water conservation as a supplement.

(4) timber forest. Soil and Water Conservation As a timber forest, artificial afforestation on barren slope should repair the water storage and soil preparation project to avoid soil erosion caused by timber harvesting. Timber forests in arid areas with little rainfall and soil erosion should be built at roadsides, villages, houses, canals, beaches, ditch bottoms and other places with good water sources and logging will not cause soil erosion.

1. 1.2 The following forest species are arranged according to different topographic positions:

(1) Slope soil and water conservation forest. According to the position, slope, site conditions and soil erosion characteristics of the barren slope, shrub forest, arbor forest and economic forest can be arranged in the upper, middle or lower part of the slope respectively.

(2) Gully soil and water conservation forest. The gully head, slope and bottom are divided into three parts, and the gully control measures should be closely combined with gully head protection, gully workshop and warping dam.

(3) Coastal soil and water conservation forest. It is mainly used to reinforce river banks, reservoirs and canals to prevent bank collapse and erosion.

(4) Surrounding soil and water conservation forest. In plain and plateau areas, roads and channels are generally combined to form a large square site, and roadside and ditches are afforested according to the requirements of farmland shelterbelt network. Afforestation near villages and houses in mountainous and hilly areas should be combined with timber in agricultural areas and greening construction in villages and towns.

1.2 forest type planning

1.2. 1 pure forest

(1) pure shrub. It is mainly suitable for arid and semi-arid areas and places with serious soil erosion and poor site conditions.

(2) Pure forest. It is mainly suitable for places with good site conditions, and the biological characteristics require pure forests.

1.2.2 mixed forest

(1) The mixed types are conifers and broad-leaved trees, trees and shrubs, trees and shrubs and herbs, and deep-rooted and shallow-rooted trees.

(2) Mixed mode

A) interspecific mixing. Adapting to barren land, planting shrubs with strong soil and water conservation, soil improvement and covering ability among trees; Or plant a tree between shrubs every 5 ~ 10.

B) mixed rows. General trees and shrubs, negative tree species and positive tree species are suitable for use.

C) ribbon mixing. Suitable for two contradictory tree species with slow initial growth. The width of forest belt should be determined according to the characteristics of tree species.

D) massive (irregular) mixing. It is suitable for places with strong competition among tree species or broken terrain and mosaic distribution under different site conditions.

1.3 tree species planning

1.3. 1 Suitable for ground and trees.

(1) Afforestation should be suitable for the ground and trees. Different forest species should be allocated according to slope, ditch, land type, different location and different site conditions in small watersheds. In the same forest species, different tree species should also be configured.

(2) According to the main ecological factors such as temperature, rainfall and soil quality, the whole country can be roughly divided into seven climatic zones with different site conditions. See Appendix A (information appendix) for the tree species suitable for each climate zone.

1.3.2 Good quality and high yield

(1) Economic forest (orchard): Excellent varieties and strong market competitiveness are required; At the same time, it should be convenient for transportation, storage and processing of value-added tree species.

(2) Fuelwood forest: The tree species are required to have strong germination, stubble resistance, barren resistance, drought resistance and high burning value.

(3) Forage forest: The tree species are required to be drought-resistant, grazing-resistant, stubble-resistant and palatable.

(4) Timber forest: The tree species are required to have good quality, high value, fast growth and high yield.

(5) Water conservation forest: it requires tree height, large crown width, rich litter and easy decomposition, deep root system, large number and wide root area; Tree species with long life, stable growth and strong resistance; Tree species with low water consumption and drought tolerance; Tree species that do not pollute the water environment.

1.3.3 On the premise of meeting the above principles, native tree species should be adopted; When the native tree species can't meet the requirements, we should introduce excellent tree species from other places through experiments.

1.4 nursery planning

1.4. 1 Counties, townships, villages or small watersheds can set up different levels of nurseries within the planning scope according to the needs of afforestation, and should avoid purchasing and transporting seedlings from other places.

1.4.2 nursery land should be a place with good soil quality, convenient management and good irrigation conditions; Should be roughly evenly distributed within the planning scope for easy use.

1.4. The nursery area should ensure that the number of seedlings can meet the annual needs of all afforestation within the planned scope. Conditional adjustment in towns, villages or small watersheds, and adjustment in counties when necessary.

1.4.4. The forest species and tree species should be prepared according to the afforestation plan, and the required forest species and tree species should be planted according to the planning requirements, so as to avoid any seedling and tree from getting due benefits. The introduction of new exotic tree species should be confirmed by experiments before it can be included in the seedling plan.

1.4.5. The construction and production of the nursery should be managed by special personnel, strictly in accordance with the technical specifications and related systems of nursery management, so as to ensure the task and quality of seedling raising.

1.5 Other related plans

1 Basic requirements of reconstruction planning. 5. 1 Residual forest, sparse forest, inefficient forest and small ancient trees are as follows:

(1) Residual forests and sparse forests should be transformed by measures such as enclosure, regeneration and replanting according to different residual sparsity and site conditions.

(2) Low-efficiency forests and small old trees should be transformed by thinning, pruning, grafting improvement, soil preparation, loosening soil and irrigation according to the reasons for the formation of different tree species and small old trees. Improper selection of tree species should be replaced by suitable tree species.

1.5.2 Woodland Road Planning

Roads with a width of 2 ~ 3 m should be set around a forest land and inside a large area of forest land, and they should be able to pass through boxcars or small motor vehicles.

1.5.3. Forest land management and protection planning

Including management measures, management organization, management equipment and management personnel planning.

2 design

2. The planting density is designed as 1

2. The expression form of1.1afforestation density.

(1) In terms of row spacing (m) and plant spacing (m), it is directly used for afforestation construction.

(2) Count the number of trees planted per unit area (hm2), which is used to count the required number of seedlings and afforestation achievements (survival rate, preservation rate, benefits, etc.). ).

2. 1.2 afforestation density of different forest species and tree species

(1) The planting density of timber forest should be 2000 ~ 3000 plants per hectare, which can be relaxed to 600 ~ 5000 plants per hectare according to the characteristics of tree species and local conditions.

(2) The planting density of economic forests and orchards should be 0/000 ~ 2,000 plants per hectare, which can be relaxed to 500 ~ 5,000 plants per hectare according to tree species and management level.

(3) The shrub-dominated forage forest and firewood forest should be 0-20,000 clumps per hectare/kloc-0, and different tree species can be as little as 6,000 clumps per hectare.

(4) The tree density of water conservation forest should be 0/000 ~ 3000 plants per hectare, and the shrub density should be 2000 ~ 4000 plants per hectare.

2. 1.3 Planting density under different site conditions

(1) The afforestation density in areas with good hydrothermal conditions in South China is higher than that in areas with poor hydrothermal conditions in North China.

(2) In the same area, the afforestation density of land with good site conditions can be greater than that of land with poor site conditions.

(3) Under the same site conditions, the planting density of planned thinning is greater than that of unplanned thinning.

(4) The planting density of agro-forestry intercropping and grain-fruit intercropping should be 30-40 plants or 50- 100 plants per hectare.

2. 1.4 Appendix B (informative appendix) lists the initial planting density of several main soil and water conservation tree species, which can be used as a reference for local design. We should adhere to the principle of adjusting measures to local conditions, and determine the afforestation density of each area and each land type through specific design on the basis of specific analysis of site conditions.

2.2 Land consolidation engineering design

2.2. 1 basic requirements

(1) Soil and water conservation afforestation should adopt soil preparation engineering to conserve soil and water and promote the normal growth of trees.

(2) Different site conditions and different forest species should adopt different forms of land preparation projects.

(3) The defense standard of soil preparation engineering can be designed according to the maximum rainfall120-year return period of 3-6h. According to different rainfall conditions in different places, different rainstorm frequencies and short-duration and high-intensity rainstorms that are most likely to cause serious soil erosion are adopted for design.

2.2.2 banded soil preparation project

(1) horizontal step soil preparation is suitable for steep slopes of15 ~ 25, with the step width of 1.0 ~ 1.5m and the reverse slope of 3 ~ 5. The horizontal distance between the upper and lower steps shall be subject to the designed green row spacing. The slope runoff of each horizontal step should be able to accommodate all or most of the infiltration on the step surface, so as to determine the width or ridge line of the step surface. It can also be designed into slope shapes, and the distance of slope separation depends on the site. The saplings are planted on the edge of the steps.

(2) Horizontal ditch soil preparation is suitable for steep slopes of15 ~ 25. The width of the ditch mouth is 0.6 ~ 1.0m, the width of the ditch bottom is 0.3~0.5m, and the depth of the ditch is 0.4 ~ 0.6m The ditch is half-dug and half-filled, and the outside is ridged with raw soil dug from the inside. Planting seedlings outside the ditch bottom. According to the designed afforestation row spacing and the storm runoff on the slope, the spacing between the upper and lower ditches and the specific size of the ditches are determined.

(3) Anti-slope land preparation is mainly used for fruit trees or other economic trees with higher requirements on the opposite land. Where the slope is gentle, the soil layer is thick and the slope surface is flat, the field surface should be inclined inward by 3 ~ 5, and the field surface should be 2 ~ 3m wide. According to the designed row spacing of fruit trees, the spacing between upper and lower terraces is determined, which is basically laid along the contour line, and the length is not limited. Embankments can be built at a certain distance to prevent water flow from gathering; The transverse slope shall be kept within 65438 0%. Dig a hole in the middle of the field to plant fruit trees.

(4) Horizontal soil preparation is suitable for gentle slopes of large plots of 5 ~10. Use machinery or animal power to turn the soil up and down along the contour line to make a horizontal ditch with a depth of 0.2~0.4m and a mouth width of 0.3 ~ 0.6m, and determine the ditch spacing according to the designed afforestation row spacing. Seedlings should be planted in the middle of the ditch bottom.

Cave-shaped soil preparation

(1) Fish scale pits are prepared. Each pit is semicircular in plane, with a long diameter of 0.8 ~ 1.5m and a short diameter of 0.5 ~ 0.8m The pit depth is 0.3~0.5m The soil in the pit is made into an arc ridge with a lower edge and a height of 0.2~0.3m (high in the middle and low at both ends). Each pit is basically arranged along the contour line on the slope, and the upper and lower rows of pits are staggered in a pin shape. According to the designed row spacing and plant spacing, the row spacing and hole spacing of pits are determined. The seedlings are planted in a pit 0.2~0.3m away from the lower edge. At both ends of the pit, the intercepting ditch with a width of about 0.2~0.3m is dug in an inverted figure of eight.

(2) Soil preparation for large pits: When planting fruit trees in extremely thin rocky mountain areas or hilly areas, a large fruit pit should be excavated on the slope with a depth of 0.8 ~ 1.0m, a circle diameter of 0.8 ~ 1.0m ... The length of each side of the square is 0.8 ~ 1.0m ... For pit arrangement, row spacing and pit spacing, please refer to 5.2.3. 1.

3 architecture

3. 1 construction time

3. 1. 1 construction time of soil preparation project

(1) It is advisable to prepare soil in autumn and winter in the previous year and plant trees in spring and autumn in the next year, which is beneficial to storing rain and snow and promoting the maturation of raw soil. Sandy land susceptible to wind erosion should be cultivated and planted.

(2) Afforestation in autumn and winter should be carried out in spring at the latest; Afforestation in rainy season and spring should be completed in the autumn of the previous year at the latest.

3. 1.2 afforestation season

(1) Afforestation should be carried out 7 ~ 10 days before seedling germination in spring, and afforestation should be carried out in the north when the soil is thawed to the planting depth.

(2) Afforestation in rainy season should be carried out in the first half of rainy season, so as to ensure that the newly planted or directly planted seedlings have a growth period of more than two months, which is conducive to safe wintering. In arid and semi-arid areas, afforestation should be combined with weather forecast when the soil moisture is good on cloudy days, and container seedling afforestation, airplane sowing afforestation and small grain sowing afforestation can be used.

(3) Afforestation in autumn and winter should be carried out after the trees stop growing and before the land is frozen. It is not suitable for afforestation in autumn in mountainous areas with severe freezing damage. Large seeds, hard shell seeds and seeds with long dormancy period should be planted directly in autumn and winter.

3.2 Construction quality requirements

3.2. 1 Construction Quality Requirements of Soil Preparation Project

(1) The location and size of each project shall be constructed in strict accordance with the design requirements, and shall not be changed at will, so as to ensure that the designed storm runoff can be stored.

(2) The fill embankments of various land preparation projects shall be compacted by layers (or compacted) with a dry density of 1.3t/m3 to ensure that they will not collapse or puncture after water storage.

(3) All kinds of zonal soil preparation projects should be leveled manually before construction. After completion, a small retaining wall with a height of about 0.2m will be built every 5 ~ 10 m to prevent longitudinal concentration of runoff.

3.2.2 Seedling quality requirements

(1) Bare-root seedlings should use primary and secondary seedlings specified in GB6000. Timber forest should choose grade I seedlings and excellent clonal seedlings specified in GB6000; Excellent varieties and qualified seedlings specified in GB6000 are selected for economic forests; Tree species that have not formulated national standards should choose seedlings with excellent varieties, strong plants and developed roots.

(2) Container seedlings should comply with LY 1000.

(3) Plant quarantine shall be implemented when seedlings are transported in long distance and in large quantities in different places.

(4) According to the afforestation task of soil and water conservation, raise seedlings nearby to avoid losses caused by long-distance transportation.

(5) The seedling age and growth status of seedlings planted in the same plot should be basically the same.

3.2.3 Quality requirements for afforestation

(1) In the strip soil preparation project, planting pits should be dug according to the designed plant spacing, and the root system extension shall prevail according to the situation of different tree species and young trees.

(2) When planting economic fruit trees, precious tree species and fast-growing and high-yield forests, the bottom of the pit should be loosened by about 0.2m, applied with base fertilizer, mixed with subsoil, and covered with a layer of virtual soil; Container seedlings should be taken out of containers whose roots are not easy to penetrate.

(3) When planting, the saplings should be straightened, the roots should be stretched and the depth should be appropriate.

(4) When filling soil, surface soil and wet soil should be filled first, then raw soil and dry soil should be filled, and compacted by layers to facilitate moisture retention.

(5) Afforestation land with irrigation conditions in arid and semi-arid areas should be watered for planting or other soil conservation measures should be taken.

3.2.4 Quality requirements for direct seeding afforestation

(1) The quality of afforestation seeds should meet the standard of qualified seeds specified in GB7908, and the seed quality should be tested according to the method specified in GB2772.

(2) The sowing amount should be determined according to seed quality, site conditions, tree species and afforestation density.

(3) The hole sowing adopts manual digging, the hole diameter is 0.2~0.3m, and the depth is 0.15 ~ 0.20m. The hole should be loosened and the grass roots and gravel should be removed. According to the size of tree species, the thickness of covering soil is 3 ~ 5 times of the seed diameter, and it is compacted with feet.

(4) When drilling, the soil at the bottom of the ditch should be loosened by animal power or machinery in combination with the horizontal soil preparation project, and drilling should be carried out according to the designed sowing amount. After sowing, cover the soil with a plow of the same thickness and then compact it.

(5) Aerial seeding, which can be used for afforestation in large areas of barren hills, barren slopes and sparse woodlands with inconvenient traffic, shall be implemented according to GB/T 15 162.

3.2.5 Quality requirements for clonal afforestation

(1) Cutting afforestation (or cutting) should choose 1 ~ 2-year-old robust branches with smooth bark as cutting. Trees with strong roots (such as willow) with a diameter of 1.5 ~ 2 cm should be buried deeply in arid areas with little exposure; Cuttings of conifers should have complete terminal buds. Cuttings are generally 30 ~ 50 cm long. Soak 12 ~ 24h in clear water first, which is beneficial to survival.

(2) Dry-cutting afforestation, and dry-cutting materials should adopt trunk sprouting strips with a length of 3-5m and a trunk diameter of more than 3cm; The planting depth is more than 50 cm.

(3) Cutting time (buried dry) should be planted with the insertion. In arid, semi-arid or other areas with insufficient soil moisture, cuttings should be planted (buried dry) when the soil moisture is good after autumn rain.

(4) When cutting (burying), the row spacing shall be determined according to the design requirements. According to the principle of deep burial, shallow exposure and practicality, first make a hole in the planting point, and then insert the cuttings into it, with the upper end slightly higher than the surface.

(5) Afforestation by districts. It is suitable for bamboo afforestation.

4 management

4. 1 young forest management and protection

4. 1. 1 Newly-built young forests should be closed for afforestation, and activities that are not conducive to the growth of young forests and damage to land preparation projects are prohibited.

4. 1.2 Before the young forest is closed, low-stalk, overgrown green manure, vegetables, medicinal materials or other cash crops should be planted in the open space available outside the tree tray without affecting the growth of the young forest. Combine farming management and give consideration to young forest tending.

4. 1.3 Loosening and weeding are mainly carried out in land preparation works. Combined with the maintenance of the project, attention should be paid to the prevention and control of rodents.

4. 1.4 Plant fixation and tillering removal. Direct seeding and cluster planting seedlings should be combined with loosening soil and interplanting in stages until the next autumn and winter. Tree species with developed roots and strong tillering ability should keep the trunk and remove tillers in time.

4. 1.5 Pruning and shaping, economic fruits should be carried out according to the specific requirements of different tree species. Timber forest pruning should be done at the lower part of the trunk 1/3 branches, broad-leaved forest should be done after the following autumn, and coniferous forest can be postponed appropriately.

4. 1.6 flat stubble rejuvenation. For tree species with germination ability, if they grow poorly due to drought, freezing injury, mechanical damage, pests and diseases, they should be rejuvenated in time.

4. 1.7 Irrigation and fertilization. Young forests should be watered in time to protect seedlings, and economic forests and fruits should be watered and fertilized according to different tree species to ensure high quality and high yield.

The survival rate was 4. 1.8. Young forests newly built last winter and this spring are carried out in different places every winter. See table 3- 1 for the sampling rate.

Table 3- 1

4. 1.9. The survival rate of young forest replanting should be 30% ~ 70%. If the survival rate is above 70% and the distribution is uniform, there is no need to replant; If the survival rate is less than 30%, the afforestation will be renewed within a time limit regardless of the afforestation area. Young forests should be replanted with big seedlings of the same tree species or small seedlings of the same age.

4.2 Forest management

4.2. 1 Special person shall take care of it to prevent human and animal injuries, forest fires, pests and rats. See 14. 2 for the requirements.

4.2.2 Pruning of arbor firewood forest and flat stubble of shrub firewood forest should be carried out every 3-5 years at the end of winter according to tree species and growth conditions. Trees should be combined with pruning, and a few plants that are not growing well and affect each other should be cut off. In steep slopes and areas with severe wind erosion, shrub stubble should be cut with equal-height belt wheels to avoid water erosion and wind erosion caused by comprehensive stubble leveling.

4.2.3 Thinning of timber forests after they become timber should be based on the design requirements, with the principle of not aggravating soil erosion, and thinning should be carried out by means of spacing trees, interlacing or spacing zones. Steep slopes and wind-blown sand areas shall not be cut in pieces. After thinning, new seedlings should be replanted in time according to the design.

4.2.4 Economic forests and orchards should be intensively managed according to the specific requirements of different tree species, regularly irrigated, fertilized and pruned, and measures such as pest control should be taken to ensure high quality and high yield.

4.2.5. If trees grow poorly or form small old trees due to various reasons, the reasons shall be investigated in time and updated.

4.2.6 For some economic forests and fruit trees, if the original varieties are not good and the economic benefits are not high, it is necessary to graft good varieties in order to obtain high quality and high yield in a short time and improve the economic benefits.

4.2.7. All kinds of land preparation works should be kept intact for a long time. Every year after the flood season to check, damaged to repair in time.

Second, understanding and implementation

This section gives a comprehensive and detailed description of the implementation of afforestation measures for soil and water conservation in wasteland control technology. The working procedures of soil and water conservation afforestation are planning, design, construction and management, including:

Planning: forest species planning, forest species planning, tree species planning, nursery planning, residual forest, sparse forest, inefficient forest, small old tree transformation planning.

Design: afforestation density design and soil preparation engineering design.

Construction: construction time and quality requirements.

Management: young forest management, forest management.

In the process of soil and water conservation forest construction, according to the different site conditions of various wasteland and the development needs of local pillar industries, soil and water conservation forest planning should be carried out first, including forest species planning, forest type planning, tree species planning and nursery planning. On the basis of planning, afforestation design should be carried out for the selected tree species and forest species, and the afforestation design should be used to guide the construction of soil and water conservation forest. The management of soil and water conservation forest should implement special management for young forest and mature forest respectively.

The main changes in this section are as follows:

In (1) standard 4. 1 Forest species planning, specification of technical terms for afforestation types, changing water and soil conservation economic forest into economic forest, water and soil conservation firewood forest into firewood forest, water and soil conservation forage forest into forage forest, and water and soil conservation timber forest into timber forest. Change "soil and water conservation forests on both sides of rivers, around lakes and reservoirs, along canals and other waters" into "coastal soil and water conservation forests" and "roadside, canals, villages and houses" into "Sifang soil and water conservation forests".

(2) Standard 4 in forest type planning. 2. Hanging joint 4 between original standard rooms. 2.2 and standard 4. 2.2. 1 delete.

(3) In standard 4. 3 tree species planning, in order to guide the construction of water conservation forests all over the country at this stage, the new standard adds "4". 3.2.5 Water conservation forest: it requires tree height, large crown, rich litter, easy decomposition, deep roots, large roots and wide root area; Tree species with long life, stable growth and strong resistance; Tree species with low water consumption and drought tolerance; Tree species that do not pollute the water environment ",increase" 5. 1.2.4. The tree density of water conservation forest should be 0/000 ~ 3000 plants per hectare, and the shrub density should be 2000 ~ 4000 plants per hectare ".

(4) Standard 4 in nursery planning. 4, the original standard of redundant text, local nursery with 4. 4. 1, the nursery is located at 4. 4.2, nursery area in 4. 4.3. Selected tree species 4. 4.4 and nursery management. 4.5, all deleted.

(5) In the design of Standard 5. 2. Soil preparation project, due to the emergence of new afforestation technology and equipment at this stage, the original standard "5. 2. 1.4 "should be deleted, and all wasteland with slope greater than 5 degrees shall not be used for afforestation except flat land such as river beach and lakeside. Delete the pause between 5. 2.2.4 and 5. 2.2. 1. Standardize technical terms and change "5". 2.2.3. Narrow terraced land preparation is changed to 5. 2.2.3. Terrace preparation in reverse slope and 5. 2.3.2. The soil preparation of large fruit tree pits was changed to 5. 2.3.2 Large pit preparation ".

(6) In Standard 6. 2.2, the original standard 6. 2.2.3 and 6. 2.2.5 was deleted, and 6 new standards were adopted. 2.2. 1, 6.2.2.2 , 6.2.2.2 .

(7) Quality requirements in Standard 6. 2.3 for planting seedlings, 6. 2.3.2 It has been supplemented and improved, adding that "container seedlings should be taken out of containers with impermeable roots".

(8) Quality requirements in Standard 6. 2.4. Direct seeding afforestation, in order to make this article more operable, is now re-enacted as "6. 2.4. 1 The quality of afforestation seeds should meet the standard of qualified seeds specified in GB 7908; And the seed quality is tested according to the method specified in GB 2772. " Add "6. 2.4.2. The sowing amount should be determined according to seed quality, site conditions, tree species and afforestation density ".

(9) Quality requirements in Standard 6. 2.5, standardized technical terms, changed "cutting" to "planting", and new technologies such as "6. 2.5.2. Interception for afforestation "and" 6. 2.5.5 Split afforestation ".

Third, show examples.

Taking afforestation in barren hills in western Liaoning as an example;

Western Liaoning refers to the western mountainous area of Liaoning Province, located in the southern section of Northeast China, which is the transition zone from Liaohe Plain to Inner Mongolia Plateau. The barren hills in western Liaoning are mainly distributed in Fuxin, Jinzhou, Huludao and Chaoyang. The types of wasteland management can be divided into grass slope and irrigation slope according to different vegetation.

1. Planning

Afforestation of barren hills in western Liaoning should focus on building soil and water conservation forests and windbreak and sand fixation forests, and appropriately develop economic forests. Pinus tabulaeformis, Platycladus orientalis, Robinia pseudoacacia, Quercus acutissima, Prunus armeniaca, Hippophae rhamnoides, Amorpha fruticosa, Lespedeza microphylla, Caragana microphylla and other tree species can be selected to build soil and water conservation forest in western Liaoning, and economic forest tree species such as cherry plum can be selected in places with good site conditions and thick soil layer near the mountain.

design

(1) soil preparation engineering design. Generally, only local soil preparation is used for afforestation in barren hills in western Liaoning. Commonly used methods are: hole preparation, fish scale pit preparation, horizontal step preparation and horizontal ditch preparation. Among all kinds of land preparation methods, horizontal ditch is the best, and small pit without land preparation is the worst. Soil preparation can be carried out in spring, summer and autumn, but rainy days are better. Western Liaoning should be carried out before the rainy season to eliminate weeds and keep moisture. In order to improve the soil moisture content and ensure the survival of young trees, it is best to prepare soil six months to one year in advance. According to different site conditions, choose appropriate land preparation methods to minimize the damage to the original natural vegetation, implement irrigation and land preparation for afforestation, and do not cause new soil erosion. In western Liaoning, the determination of soil preparation methods and specifications must be considered in combination with the needs of planting point configuration. For example, sparse economic forests can be prepared in large fish-scale pits or large blocks, while dense timber forests and soil and water conservation forests should be prepared in strip-shaped or small fish-scale pits or small blocks, with flexibility (needles are easy to see in bare rocks).

(2) Planting density design. The plant spacing of general shrub density should be 1. 0 m × 1。 5 m or 0.5 m× 1.0 m .. Positive tree species are not tolerant to shade, and high density affects growth and development, while trees with huge crown and close planting affect growth.

3. Architecture

(1) construction time. According to the climatic conditions in western Liaoning, afforestation should be carried out in early spring, usually in early April; The suitable time for afforestation in rainy season is the end of "one autumn" and the beginning of "two autumn", and afforestation should be done in time after the 1 soaking rain. Afforestation in autumn is generally carried out in the middle of 10, but some measures should be taken, such as cutting off the trunk (broadleaf trees) or covering the soil for cold protection (conifers).

(2) Construction quality. The location and scale of all kinds of land preparation projects shall be constructed in strict accordance with the design requirements, and the designed storm runoff shall be ensured. The seedlings of afforestation tree species are selected with excellent varieties, strong plants and developed roots.

manage

Young forest tending and protection is also a key technical measure to improve the survival rate and preservation rate of afforestation and accelerate the growth of young forests. Its main contents include weeding, loosening soil, fertilizing, preventing pests and diseases and preventing the harm of animals (mice, etc.). ). The main practices of forest management are regular pest control, pruning, fertilization and intertillage every year.

(References: Wang Jingxue, Wang Shizhong, et al. Afforestation technology of barren hills in western Liaoning. Shelterbelt Science and Technology, 2008 (5): 127 ~ 128. )