JP3586250B2 - Revegetation method of vegetation slope - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for re-greening a slope such as a slope where existing vegetation is growing.
[0002]
[Prior art]
For slope stabilization, slope protection, vegetation restoration, etc. on slopes or degraded lands such as slopes (including arbitrarily sloped slopes) that can occur due to national land development or natural disasters, etc. Chemical modification is widely performed (except when the slope is unstable). Plants that are diversified by slope revegetation include exotic herbs such as creeping red fescue, orchardgrass, tall fescue, Kentucky bluegrass, weeping grab frus, bermudagrass, bahiagrass, white clover, etc., pampas grass, mugwort, knotweed And native herbaceous plants, such as medakagi, and woody plants such as komatsunagi, yamahagi, and weaselfish.
[0003]
In slopes such as slopes that have been subjected to slope revegetation (hereinafter referred to as "vegetation slopes"), any of the introduced herbaceous vegetation or woody vegetation, such as goats, dominate, Vegetation transition may be stagnant or regressed due to the overgrowth of vines and S. var. In such a state, the original purpose of vegetation work, that is, the purpose of realizing a diverse woody plant community cannot be achieved. Hereinafter, exotic herbs, native herbs and woody plants that are introduced plants, and weeds that are invasive plants, growing on slopes or other slopes are referred to as “existing vegetation”.
[0004]
Conventionally, as a method of re-greening a vegetation slope that has led to stagnation or regression of vegetation transition as described above, after cutting grass and woody plants that have already been formed on the slope, etc., the normal slope again. A method of constructing a revegetation method, a method of reconstructing a revegetation method after removing a surface layer of an existing vegetation slope, and the like are performed.
[0005]
However, these re-greening methods involving civil engineering involve problems such as a large amount of cost, a period of construction, and restrictions on traffic regulations. As a method for addressing this problem, the present applicant discloses a method for revegetating herbaceous vegetation into a woody plant community more simply in particular in Japanese Patent Application Laid-Open No. 8-284171 (Japanese Patent No. 2857599). Also, as a material for revegetation of herbaceous vegetation, there is a product that uses a vegetation cylinder bag enclosing guest soil materials and tree seeds and attaches it to the herbaceous vegetation surface to re-vegetate by woody plants. It is commercially available.
[0006]
The method described in the above-mentioned Japanese Patent Application Laid-Open No. 8-284171 discloses a vegetation slope in which vegetation transition is stagnant or regressed due to the growth of alien herbs introduced by slope revegetation or invasion of weeds such as kuzu and swordfish. This is a method for introducing woody plants into plants, the outline of which is as follows. That is, a fibrous layer containing a fiber material selected from natural mineral fiber and biodegradable plastic fiber is sprayed and formed to a thickness of 2 to 5 cm on the existing vegetation surface, and then a growth base is sprayed and formed thereon. It also discloses a method of mixing a bonding material in the fibrous layer, and a method of laying a net having a mesh enough to suppress budding instead of the fibrous layer. These fibrous layers or nets function as re-emergence suppressing layers for suppressing re-emergence of existing vegetation.
[0007]
[Problems to be solved by the invention]
Here, in slope revegetation, either a sowing method or a planting method is selected as a specific vegetation method according to the replanting target, the location condition of the slope, the weather condition, and the like. The method disclosed in Japanese Patent Application Laid-Open No. 8-284171 aims at re-greening existing vegetation by sowing. Therefore, in general, it is an effective method when a seeding work which is a full-scale construction can be applied.
[0008]
However, when a planting work is applied, since the planting work is generally performed partially, it is not always necessary to entirely form the re-emergence suppressing layer. Creating a re-emergence-suppressing layer over the entire surface causes an increase in cost. Therefore, in the case of planting works, a more economical and rational regreening method is demanded.
[0009]
Furthermore, since most of the slopes that require regreening are road slopes that are already in use, it is preferable to use a method that can be performed as easily as possible without significant traffic control during regreening.
[0010]
From the above, the following are listed as specific requirements in the revegetation method by planting.
(1) It is necessary that a large amount of cut grass, trees, etc. does not occur during planting.
(2) In general, since the slope covers a large area, it is difficult to perform regular management after planting, because it is costly and time-consuming. Therefore, regular management after planting is unnecessary. Cost.
(3) It is necessary to be able to plant only by processing the minimum range of existing vegetation necessary for planting.
(4) In order to grow the planted tree smoothly, it is necessary that existing plantations around the planted tree can avoid pressure from the planted tree after planting.
(5) In particular, when the existing vegetation is a woody vegetation such as a Yamahagi community, a Itachihagi community, a Komatsunagi community, etc., there is a problem that the planted tree is under pressure because the existing tree is covered by the planted tree. For this reason, it is necessary to suppress the re-emergence of these harvested existing woody plants, and to prevent the planted trees from being subjected to pressure even if the growth of these existing woody plants is restored.
[0011]
An object of the present invention is to provide a method for re-greening by vegetation that satisfies the above requirements in a method for re-greening a vegetation slope.
That is, the present invention, on slopes such as slopes, after the revegetation work, various exotic herbs, introduced vegetation slopes that have become dominated by various revegetation plants such as native herbs such as hedges, The vegetation transition is stagnant or regressed, and the existing vegetation slopes dominated by herbs such as pampas grass, goldenrod, kudzu, etc. are revegetated by introducing woody plants into them, and the vegetation transition on the slopes To provide a method for revegetation of vegetation slopes that achieves restoration of ecosystems, environment and landscape.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, an embodiment of the method for revegetation of a vegetation slope according to the present invention provides a method for planting a new seedling at least on a vegetation slope on which existing vegetation grows so as to avoid pressure on the new seedling. A step of cutting existing vegetation growing in a surrounding area of a planting position (at this time, before planting, which is a planned planting position), and a valley from a transverse center line in the surrounding area where the cutting was performed. Planting the new seedling on the side portion.
Preferably, in the above-described embodiment, the surrounding area where mowing is performed has a shape in which the length in the transverse direction is longer than the length in the horizontal direction.
Preferably, in the above embodiment, a re-emerging suppression layer is formed on a part or all of a mountain-side portion from a transverse center line in a peripheral region where the mowing is performed.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As described above, existing vegetation on slopes and other slopes that have been revegetated at least once is favored by various exotic herbs and greening plants represented by legumes such as Yamahagi, Itachihagi and Komatsunagi. In the case of occupation, invasive weeds such as Japanese pampas grass, scum, and S. americana are often prosperous. In these cases, it can be said that the vegetation transition is stagnant and progress is not proceeding smoothly.
[0014]
In recent years, slope forestation has been widely used as a method to fix carbon dioxide that causes global warming.However, even if the transition of vegetation is not progressing smoothly as described above, forests of existing vegetation It is required to actively introduce woody plants in order to promote the transformation. Also in the present invention, a planting work is applied for introducing a woody plant.
[0015]
When trying to plant a woody plant in existing vegetation, it is necessary to remove the existing vegetation first because the planting work itself is hindered in terms of workability and the like. Therefore, in the present invention, cutting of existing vegetation is performed in a region around a planting position of a new seedling. The range in which the mowing is performed is a region around a position where a new seedling is to be planted. The cutting area of this surrounding area is generally small if the existing vegetation is a herbaceous plant with a short height, but if the height of the plant is rather high, such as Japanese pampas grass, it is wider than a plant with a short height. Is desirable. Further, when the existing vegetation is a woody plant such as a hedge, a larger area is required in consideration of the overgrowth of the branches. The cutting area of the surrounding area is set in consideration of such conditions.
[0016]
In addition, the cutting area of the surrounding area is basically sufficient if it is possible to ensure that the planted trees are sufficiently exposed to sunlight. The suitable cutting area is usually determined by judging from the state of the existing vegetation, the size and shape of the seedling to be planted, the planting method, and the like. Although the cutting area is not particularly limited, in consideration of minimizing the amount of cut grass and trees, the crossing direction of the slope (vertical direction, slope direction) and the horizontal direction (slope of the slope) are considered. It is preferable that the length of the cut surrounding area in the left-right direction is set to be about 30 to 200 cm.
[0017]
The mowing of the area around the planting position (the planned planting position before planting) involves removing existing vegetation that hinders planting, and after planting, new seedlings are placed under pressure by existing vegetation. It is important in avoiding receiving. FIGS. 1A to 1C are diagrams showing an example of the shape of the surrounding area 10 at the planting position where the mowing is performed, and are views seen from a direction perpendicular to the slope. Therefore, the upper part of the figure corresponds to the upper part of the slope, and the lower part corresponds to the lower part of the slope.
[0018]
As shown in each embodiment of FIG. 1, when re-greening is performed on a slope such as a slope, the shape of the surrounding area 10 where the mowing is performed is set to be longer in the transverse direction than in the horizontal length L1 of the slope. It is preferable to make the shape longer. As a result, it is possible to minimize the influence of pressure on existing vegetation located above the sloped side of the planted tree and the degree to which existing vegetation regenerated from the mowing part is pressed against the planted tree. .
[0019]
The shape of the surrounding area 10 where the mowing is performed is generally an ellipse shown in FIG. 1A or a rectangle shown in FIG. 1B. The planting position is provided in the valley-side portion 14 with respect to the transverse centerline 15 of the surrounding region 10 as described later. Therefore, if the mountain-side portion 13 of the surrounding area 10 can be secured wider than the valley-side portion 14, the effect of preventing pressure from being exerted by existing vegetation is improved. Therefore, the shape of an inverted isosceles triangle shown in FIG. 1C may be used. The planting position is not limited to a special shape as long as the planting position is provided in the valley-side portion 14 with respect to the transverse centerline 15 of the surrounding region 10.
[0020]
After cutting the surrounding area 10, a new seedling is planted in the valley side portion 14 (hatched portion) from the transverse center line 15. In a slope, the vegetation on the hill side of the slope is often inclined toward the valley side, and it is general that the leaves, branches, and the like hang down to the valley side. Therefore, when planting on the transverse center line 15 of the cut surrounding area 10 or on the mountain side portion 13 therefrom, it will be subjected to pressure by existing vegetation in a short period after construction. Therefore, by planting in the valley-side portion 14 of the transverse center line 15 of the surrounding area 10, it is possible to avoid the pressure caused by the drooping or covering of existing vegetation for a long time after construction.
[0021]
The planting position is particularly suitable in the valley-side portion 14, particularly in the vicinity 17 (shaded portion) of the horizontal center line 16. Therefore, in practice, the central portion 18 of the valley side portion 14 is often selected as the planting position. In addition, the planting method of the planting tree is not particularly limited, and any shape and planting method such as a sprouting seedling, a container seedling, a unit seedling, and an adult seedling can be applied.
[0022]
Further, it is preferable to form a re-emerging suppression layer at least partly or entirely on the mountain side from the planting position in the surrounding area 10 where the mowing is performed. The re-emergence suppressing layer plays a role of suppressing the re-emergence of the mown plant and of preventing the planted tree from being pressed for a long period of time. That is, the re-emergence suppression layer prevents re-emergence (regeneration) of existing vegetation and prevents germination of weed seeds and the like scattered from the surroundings after cutting. The re-emergence suppressing layer may be any layer that can cover (mulching) the surrounding area 10 that has been cut, and specifically, spraying sandbags, various multi-sheets, fiber materials, coating with multi-materials, and the like. A known method can be applied. In particular, a method using a sandbag is highly effective.
[0023]
FIG. 2 is a diagram schematically showing a cross section of a slope 28 constructed by the re-greening method according to the present invention. A planting tree 24 is planted in a valley-side portion in the surrounding area 22 that has been cut on the slope 28, and a re-emergence suppressing layer 23 (such as a sandbag) is provided in a mountain-side portion 25 of the planting tree 24. In the illustrated example, the re-emergence suppressing layer 23 is provided not on the entire mountain-side portion 25 but on a part thereof, but this is a necessary minimum pressure-prevention measure. This makes it possible to prevent the planted tree 24 from being pressed by the existing vegetation 27. The re-emergence suppressing layer 23 should be provided so as to cover at least the mountain-side portion 25 than the planted tree 24, but it is best to provide the layer so as to cover the entire surrounding region 22 including the valley-side portion 26.
[0024]
【The invention's effect】
As described above, according to the present invention, woody plants are introduced into slopes such as slopes where various greening plants and herbs (weeds) prosper or vegetation transitions are stagnant or regressed. A greening method was presented.
[0025]
ADVANTAGE OF THE INVENTION According to this invention, it is possible to prevent the pressure of the planted tree after planting for a long time only by cutting the required minimum area to the existing vegetation, and it is a very useful method. As a result, the vegetation transition from herbaceous vegetation to woody vegetation can be greatly accelerated, and the quality of greenery that contributes to the fixation of greenhouse gas carbon dioxide, Greening becomes feasible.
[Brief description of the drawings]
FIGS. 1A to 1C are diagrams showing an example of a shape of a surrounding area of a planting position where mowing is performed.
FIG. 2 is a diagram schematically showing a cross section of a slope constructed by the re-greening method according to the present invention.
[Explanation of symbols]
Reference Signs List 10 Surrounding area 13 for cutting 13 Mountain side part of surrounding area 14 Valley side part of surrounding area 15 Transverse center line of surrounding area 16 Horizontal center line of surrounding area 17 Suitable planting position 18 Actual planting position L1 Surrounding area The horizontal length L2 of the surrounding area The transverse length of the surrounding area 22 The surrounding area 23 Re-emergence suppressing layer 24 Planting tree 25 Mountain side portion from planting tree 26 Valley side portion from planting tree 27 Existing vegetation 28 Slope

Claims (3)

On the vegetation slope where the existing vegetation grows, the step of cutting the existing vegetation growing at least in the area around the planting position of the new seedling in order to avoid pressure on the new seedling; Planting the new seedlings in a valley side of the region from the transverse center line in the region. The revegetation method of the vegetation slope according to claim 1, wherein a shape of the surrounding area in which the mowing is performed is a shape in which a length in a transverse direction is longer than a length in a horizontal direction. The revegetation slope revegetation method according to claim 1 or 2, wherein a re-emerging suppression layer is formed on a part or all of a mountain side portion from a transverse center line in the surrounding area where the mowing is performed. .

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