Vegetation of ridges

Vegetation of ridges

Living protective layer of the upper watershed

Mountain ridge vegetation should serve not just a decorative function, but an engineering and ecological function. It bears the brunt of wind, rain, snow, solar radiation, and sudden temperature changes.

The state of the vegetation cover on the peaks determines:

will the soil be preserved;

will the water begin to be absorbed or will it immediately flow down;

will the snow linger;

will the first erosional furrows appear;

will the springs be supplied with water;

Will the ecosystem be able to withstand drought, fire and abnormal rainfall?

The main principle:

What needs to be created on the ridge is not a forest wall, but a low, mosaic and stable ecosystem.

Tall trees aren't a universal solution. On exposed treetops, they can increase wind loads, fall when the soil becomes saturated, and damage the thin soil layer with their roots.

1. The main functions of vegetation

1.1 Interception of precipitation

Leaves, branches, needles, stems and mosses hold back some of the rain before it reaches the soil.

This allows:

reduce the impact of drops;

reduce the destruction of the soil crust;

distribute water over time;

direct moisture along the stems to the roots;

reduce instantaneous surface runoff.

During a heavy downpour, vegetation cannot retain all the water, but it significantly changes the nature of its flow to the surface.

1.2. Slowing down surface runoff

Stems, sod, roots, plant litter and fallen branches create roughness.

Water:

loses speed;

distributed over a larger area;

retains sediment;

gets more time to penetrate the soil;

less often forms a concentrated flow.

1.3. Soil stabilization

Different plants hold different layers of soil.

Superficial roots:

tie the turf;

protect the soil from erosion;

hold small stones;

stabilize the topsoil.

Deep roots:

penetrate into cracks;

strengthen local areas;

create channels for air and water;

connect the top layer with deeper horizons.

However, deep-rooted plants cannot be automatically considered safe. In fissured or landslide-prone areas, roots can channel water into weak geological layers.

1.4. Wind protection

Low vegetation reduces wind speed immediately at the surface.

She:

reduces the blowing away of fine soil;

holds snow;

reduces evaporation;

protects young plants;

retains seeds and organic matter;

softens temperature fluctuations.

The most effective is not a solid wall, but rather heterogeneous semi-permeable vegetation.

1.5. Soil formation

At the tops the soil is often very thin and develops slowly.

Vegetation participates in soil formation through:

root death;

accumulation of leaves and needles;

retention of wind-blown dust;

destruction of stone by roots and microorganisms;

development of mushroom networks;

the work of insects and soil fauna.

Even a few millimetres of new organic layer are of great importance for the ridge ecosystem.

2. Multi-tiered structure

The ridge vegetation should consist of several complementary tiers.

Tier 0. Biological soil crust

This is the lowest and often underestimated layer.

It may include:

bacteria;

cyanobacteria;

microscopic algae;

mushrooms;

lichens;

small mosses.

Biological crust:

binds soil particles;

reduces wind erosion;

retains moisture;

participates in the accumulation of organic matter;

creates conditions for plant germination.

On dry ridges, the damaged soil crust can regenerate very slowly. Therefore, the movement of people, vehicles, and animals must be directed along restricted routes.

Tier 1. Mosses and lichens

Mosses and lichens are the first to colonize:

stone surfaces;

cracks;

thin soil pockets;

cold and windy areas;

areas with frequent fog.

Their functions:

dew and fog retention;

reduction of evaporation;

protecting the soil from raindrops;

dust accumulation;

gradual formation of an organic layer;

creating a microenvironment for seeds.

This layer cannot be considered useless due to its low altitude. On the most exposed peaks, it can be the main stable vegetation cover.

Tier 2. Groundcover plants

This includes low creeping and cushion-shaped forms.

They:

cover exposed soil;

reduce overheating;

protect from the wind;

retain small particles;

form moist microzones;

support insects and microorganisms.

Preference is given to plants that:

do not require a deep fertile layer;

tolerate wind;

drought resistant;

quickly recover from damage;

do not form a heavy homogeneous mass.

Layer 3. Cereals, sedges and turf-forming grasses

This is the main soil-protecting layer.

Turf-forming species create a dense root network that:

strengthens the top layer;

filters water;

slows down the surface flow;

reduces the development of gullies;

holds snow;

protects the soil from trampling.

Should be combined:

dense turf grasses;

loose turf grasses;

sedges of damp areas;

drought-resistant cereals;

local flowering species.

One species should not occupy the entire area.

Tier 4. Herbaceous forbs

Mixed herbs increase the stability of the system.

It includes:

legumes;

umbrella;

Asteraceae;

bulbous;

medicinal plants;

forage species;

plants for pollinators.

Different root systems utilize different soil horizons. This reduces direct competition and improves soil structure.

Flowering plants support:

wild bees;

butterflies;

beetles;

birds;

natural dispersal of seeds.

Tier 5. Low shrubs

Low shrubs are a key element of ridge architecture.

They:

they extinguish the wind;

retain snow;

collect fog;

form a shadow;

protect herbs;

create shelters for animals;

strengthen soil pockets;

retain organic matter.

In wind-blown areas the following are preferable:

creeping forms;

dense low bushes;

plants with flexible branches;

species that are able to recover from freezing and damage.

Tier 6. Tall shrubs

Tall shrubs are planted not on the most open ridge line, but:

just below the top;

on the leeward side;

in saddles;

near natural depressions;

in places protected by stones;

along the edges of wet areas.

They form the transition from low ridge cover to forested slope communities.

Tier 7. Trees

Trees on ridges are allowed only where they correspond to the natural altitudinal zone, soils and wind regime.

Preferred:

low trees;

multi-stemmed forms;

flexible rocks;

species with a stable root system;

local genetic lines;

trees growing naturally at the upper forest line.

Tall, solitary trees on an open ridge are particularly vulnerable.

3. Not a forest, but a mosaic

The ridge area should consist of alternating sections:

open low grass;

mosses and lichens;

shrub groups;

stone outcrops;

wet pockets;

small forest islands;

natural water passages;

fire breaks.

A mosaic structure is better than a solid planting because it:

reduces the likelihood of massive windfall;

reduces the spread of fire;

supports more types;

preserves natural viewing and ventilation areas;

distributes snow;

prevents the formation of a single heavy plant mass;

is easier to recover from damage.

4. Location of vegetation relative to the wind

Windward side

The windward side receives:

maximum wind blow;

slanting rain;

ice particles;

transportable sand;

increased mechanical load.

The following are located here:

mosses and lichens;

low turf grasses;

cushion plants;

creeping shrubs;

rare flexible bushes;

stone-vegetation strips.

Tall vegetation is limited here.

Upper ridge line

At the watershed line itself, vegetation should be low and semi-permeable.

Main tasks:

preserve the soil;

do not create strong turbulence;

do not block the water distribution;

do not form a heavy snow wall;

do not change the watershed unless necessary.

Leeward side

The leeward zone is usually more protected, but eddies and snow accumulations can occur here.

Allowed:

taller shrubs;

small trees;

forest islands;

nursery areas;

humid microzones.

It is not advisable to create a continuous dense band immediately behind the ridge, as this can increase turbulence.

5. Location relative to water

Dry, raised areas

The driest and most wind-blown zones are populated by:

lichens;

low grains;

cushion-shaped plants;

drought-resistant grasses;

creeping shrubs.

Shallow depressions

In depressions with temporary moisture are located:

taller grasses;

moisture-loving cereals;

sedges;

low shrubs;

plants with a high capacity to retain sediment.

Initial runoff lines

These areas should not be completely planted with dense bushes.

What is needed here:

flexible herbs;

plants with a dense root system;

species resistant to temporary flooding;

open areas for the safe passage of water.

Vegetation should slow the flow but not create a tree jam.

Spring and seepage areas

The following are used near the sources:

moisture-loving herbs;

sedges;

mosses;

low shrubs;

plants that stabilize the banks.

Do not plant species that may over-dry a small spring or destroy it with their roots.

6. Root architecture

A stable ridge requires a combination of different root types.

Surface mesh

Created:

cereals;

sedges;

ground cover plants;

mosses and low grasses.

It holds the most vulnerable top layer.

Fibrous roots

The fibrous system:

binds the soil;

distributes moisture evenly;

prevents the development of small gullies;

quickly recovers from damage.

Taproots

Taproots:

use deep moisture;

help plants survive drought;

create vertical biochannels.

However, on thin soils and fissured rock, such species should be used with caution.

Rhizome plants

Rhizomes help:

quickly close the damaged surface;

stabilize small embankments;

recover from a fire or grazing.

Aggressive rhizomatous species can crowd out native flora, so invasive plants should be avoided.

7. Pioneer plants

In heavily disturbed areas, plants capable of preparing the environment for other species are first introduced.

Pioneers must:

tolerate poor soil;

withstand drought and wind;

take root quickly;

retain sediment;

provide organic matter;

create a shadow;

do not become invasive.

After the territory stabilizes, the proportion of pioneer species gradually decreases, and the structure becomes more diverse.

8. Nitrogen-fixing plants

Nitrogen-fixing plants help restore poor soils.

They can:

enrich the soil with available nitrogen;

support neighboring plants;

accelerate the accumulation of organic matter;

participate in recovery efforts after fires.

They should not be planted as the sole base vegetation. Excess nitrogen can alter the natural composition of high-altitude communities and favor undesirable, fast-growing species.

9. Plants for catching fog

In cloudy and coastal mountains, vegetation can collect horizontal precipitation.

Plants with:

small leaves;

pubescent surface;

dense branching;

pine needles;

rough bark;

multi-level crown.

Droplets of fog settle on the plant, combine and flow into the soil.

These species are planted in groups to form wet islands, but not to create a continuous wind wall.

10. Snow-retaining vegetation

Vegetation should distribute snow rather than accumulate it into dangerous masses.

For this purpose the following are used:

low shrubs;

sparse shrub belts;

hard grains;

mosaic islands;

small groups of trees below the ridge line.

It is necessary to avoid:

solid dense stripes;

landings under avalanche-prone cornices;

tall vegetation causing uneven snow accumulation;

plantings above roads and buildings without snow calculations.

11. Vegetation and abnormal rainfall

During normal rainfall, the vegetation retains and distributes moisture.

In case of abnormal downpour he must:

remain fixed;

do not turn into a floating mass;

do not block emergency channels;

do not transmit the flow to one point;

do not provoke the uprooting of soil along with the roots.

Therefore, the following should not be placed near extreme runoff paths:

dense thickets of large shrubs;

poorly secured wood debris;

trees with a high risk of falling;

solid wicker barriers.

12. Vegetation and strong wind

When assessing wind conditions the following are taken into account:

plant height;

crown shape;

flexibility of branches;

sail area;

root depth;

soil stability;

single or group arrangement;

presence of snow or ice load.

More stable:

low forms;

multi-stemmed bushes;

plants with flexible branches;

groups of unequal height;

species with a gradual transition from lower to higher tiers.

Most vulnerable:

single tall trees;

same-age series;

plants with superficial roots in moist soil;

heavy crowns;

damaged or leaning trees.

13. Fire protection structure

The vegetation on the ridges should prevent the rapid spread of fire.

For this purpose the following are created:

mosaic areas;

gaps between shrub groups;

strips of low-flammability vegetation;

access to water points;

controlled grazing areas;

areas for removing excess dry matter;

separation of coniferous and shrub areas;

safe passages for fire services.

It's not a good idea to completely clear the ridge of vegetation. Bare soil left after a fire or clearing becomes a source of erosion.

14. Local species and genetic origin

The project should be based on local plants adapted to:

height;

wind;

length of winter;

type of precipitation;

local soil;

drought;

fires;

animals;

diseases and pests.

It is advisable to use seeds and planting material from the same region and a similar altitude range.

A plant of one species from the lowlands may have different genetic adaptations and not tolerate the conditions of the summit well.

15. High-altitude nurseries

For large projects, special mountain nurseries are created.

They contain plants:

grown in the local climate;

undergo hardening by wind and cold;

receive limited watering;

develop a compact root system;

adapt to local soil microflora;

are selected for stability.

Plants that are grown too “hothouse” often die after planting, even if they formally belong to the appropriate species.

16. Recovery methods

Natural recovery

It is used where the following are preserved:

seed bank;

mother plants;

soil biota;

natural dispersal of seeds.

Enough:

remove the destructive load;

limit grazing;

close traffic;

protect the soil;

monitor the recovery.

Supported natural recovery

Additionally, the following is performed:

protection of young plants;

local mulching;

removal of invasive species;

installation of microbarriers;

reseeding of local grasses;

transfer of a small amount of local litter.

Active recovery

Necessary in heavily damaged areas.

Includes:

preparation of soil pockets;

sowing;

planting shrubs;

transfer of mosses and lichens using a special technique;

temporary watering;

protection from animals;

wind screens;

continuous monitoring.

17. Sowing and planting

On open ridges, simple seed broadcasting is often ineffective.

Seeds can:

be carried away by the wind;

dry out;

be washed away by a downpour;

become animal feed;

have no contact with the soil.

More effective:

micropocket seeding;

sowing behind stone lines;

use of protective mulch;

local seed mats;

sowing before the appropriate rainfall season;

mixing species with different germination times;

temporary protection with nets.

18. Mulching

On ridges, mulch should be wind-resistant.

Suitable for:

small branches;

coarse wood chips;

stone mulch;

local plant litter;

fixed fiber mats;

a mixture of organic matter and small stones.

It's dangerous to use a thick layer of light, dry straw. It can be blown away by the wind, accumulate in a hollow, and become a fire hazard.

19. Grazing and wild animals

Animals are part of the ecosystem, but overexposure destroys the vegetation.

It is necessary to take into account:

number of animals;

grazing season;

soil condition;

grass height;

presence of young bushes;

location of watering places;

concentration of traffic along the paths.

Applicable:

rotation sections;

seasonal restrictions;

temporary fencing;

mobile watering places;

protection of individual shrubs;

recovery periods.

20. Invasive species

On disturbed ridges, species that:

displace native plants;

change the fire regime;

consume a lot of water;

create uniform thickets;

poor soil retention;

toxic to animals.

Control should include:

early detection;

mapping;

removal before seed formation;

restoration of local vegetation;

monitoring for reappearance.

Removing an invasive plant and leaving the soil bare is the wrong solution. The vacated space should be immediately occupied by a sustainable native community.

21. Vegetation monitoring

The condition of the cover is assessed by the following indicators:

percentage of bare soil;

total vegetation cover;

proportion of native species;

variety of tiers;

root coverage density;

condition of mosses and lichens;

number of young plants;

traces of grazing;

wind damage;

area after fires;

volume of retained snow;

amount of sediment;

the appearance of new gullies;

spread of invasive species.

The following are used for observations:

permanent test sites;

terrestrial photography;

drones;

spectral cameras;

seasonal cards;

humidity sensors;

WOOD Plant ID;

Mountain Digital Twin.

22. Functional groups of plants

The selection of vegetation is carried out not only by species names, but also by functions.

23. Example of a spatial diagram

Vegetation is distributed from the windward to the leeward slope as follows:

Windward slope:

mosses → lichens → tussock grasses → creeping shrubs.

Ridge line:

low mixed grasses → ground cover forms → sparse shrub groups.

Leeward zone:

tall grasses → shrubs → small groups of trees.

Upper ravine:

sedges → moisture-loving grasses → edge-stabilizing shrubs.

Initial watercourse:

flexible grasses → open water path → root-strengthening plants along the banks.

24. What not to do

On the ridges it is forbidden to:

plant one species over a large area;

create continuous rows of tall trees;

use invasive fast-growing species;

completely cover natural drainage lines;

plant large trees on unstable slopes;

place dense bushes in hazardous waterways;

apply light, loose mulch;

destroy moss and lichens for the sake of “improvement”;

to massively fertilize natural high-mountain communities;

introduce plants without fire risk assessment;

consider the number of landings as the main indicator of success.

25. Stages of vegetation formation

Stage 1. Protection of remaining vegetation

First, everything that is already working stably is saved.

Stage 2. Covering bare soil

Mosses, groundcover plants, grasses and stone-plant protection are introduced.

Stage 3. Formation of turf

A dense root layer is created that holds the surface.

Stage 4. Introduction of mixed herbs

Biological and functional diversity increases.

Step 5. Planting low shrubs

Wind and snow retention islands are formed.

Stage 6. Formation of transition zones

Tall shrubs and small trees are introduced into protected areas.

Stage 7. Self-regulation

The system is gradually moving from permanent planting to natural regeneration.

The final principle

Ridge vegetation is the first living defense system of the entire catchment area.

She must:

hold the soil;

disperse water;

reduce wind speed;

collect fog and dew;

safely hold snow;

maintain biodiversity;

survive droughts, frosts and fires;

do not block extreme flow;

gradually transition into forest and shrub communities of the lower slopes.

The main goal is not to cover the summit with trees, but to restore the natural multi-layered structure that is appropriate for the altitude, wind, water, soil and geology of the particular ridge.

Proper ridge vegetation does not stop natural processes, but makes them slower, more uniform and safer.