Trees and shrubs of marshy areas

Trees and shrubs of marshy areas

DREVO Living Wetlands Plant Architecture

Concept

The woody and shrubby vegetation of swamps performs several functions:

stabilizes the banks;

slows down surface runoff;

creates shade and cool areas;

forms shelters and nesting sites;

provides pollen, nectar, seeds and berries;

retains organic matter and sediment;

connects the swamp with forests, rivers and agricultural areas;

creates dead wood needed by fungi and invertebrates.

Alder, willow, and birch are the most typical trees in temperate rainforests. In floodplains, they may be joined by ash, elm, poplar, and oak, which are tolerant of periodic flooding.

The main principle:

Plants should be selected based on the actual duration of flooding, the depth of groundwater, and the properties of the soil, and not just on the general characteristic of “wet place.”

1. Hydrological landing zones

Zone A - permanent or prolonged flooding

Conditions:

the water stands still for most of the year;

the soil is almost constantly saturated;

the oxygen content in the soil is low;

Seasonal fluctuations in levels are possible.

Trees are planted here in limited numbers, mainly on small hills and natural islands.

Suitable trees

black alder -Alnus glutinosa;

gray alder -Alnus incana;

white willow -White willow;

brittle willow -Willow × fragile;

Ash willow in shrub form -Salix cinerea;

downy birch -Birch pubescent;

swamp cypress -Taxodium distichum, only in regions where its use is environmentally acceptable.

Alder, birch and willow are the main species of many European rainforests.

Suitable shrubs

willow-eared —Golden willow;

ash willow -Salix cinerea;

purple willow -Salix purpurea;

willow triandra -Salix triandra;

Marsh myrica -Myrica gale;

brittle buckthorn —Alder buckthorn;

marsh wild rosemary -Rhododendron tomentosum, only in the natural range;

Myrica - regional speciesMyrica.

Restrictions

Continuous forests cannot be created in this zone. Excessive overgrowth:

shades open water;

displaces rare marsh plants;

accelerates the accumulation of wood organic matter;

may alter evaporation and hydrology;

reduces the habitat of waders, amphibians and light-loving insects.

2. Zone B - seasonally flooded floodplain

Conditions:

flooding from several days to several months;

in summer the surface may dry out;

river sediments are deposited;

the soil is rich in organic matter and minerals.

This is the main zone of the floodplain forest.

First-tier trees

white willow -White willow;

black poplar -Black poplar;

white poplar -White poplar;

black alder -Alnus glutinosa;

gray alder -Alnus incana;

smooth elm -Smooth elm;

small elm -Elm tree;

narrow-leaved ash -Narrow-leaved ash;

English oak -Oak treeat higher places;

oriental plane tree -Oriental plane treewithin the limits of natural or acceptable regional use.

European alluvial forests are characterized by gray alder and willow forests, and at higher floodplain levels, oak-elm-ash communities. In the Mediterranean, narrow-leaf ash, oriental plane trees, tamarisk, and oleander are also found.

Shrubs

Viburnum arvensisViburnum opulence;

blood-red dogwood -Blood-red hornbeam;

white dogwood -White dogwood, only in natural or permitted region;

European euonymusEuonymus europaeus;

brittle buckthorn —Alder buckthorn;

black currant -Ribes nigrum;

black elderberry -Sambucus nigra;

common bird cherry -Prunus padus;

various local shrub willows.

3. Zone C – humid forest without permanent flooding

Conditions:

high groundwater level;

overwatering in spring;

in summer the soil remains moist, but not necessarily flooded;

better supply of oxygen to the roots.

Main trees

English oak -Oak tree;

smooth elm -Smooth elm;

small elm -Elm tree;

common ash -Tall ash, only on suitable soils and taking into account regional diseases;

narrow-leaved ash -Narrow-leaved ash;

field maple -Acer campestre;

white maple —Maplein cool, damp areas;

small-leaved linden -Cordate lime treeat the transition to a drier forest;

downy birch -Birch pubescent;

black alder -Alnus glutinosa;

aspen -Aspen.

Shrubs

hazel -Corylus avellana;

viburnum -Viburnum opulence;

door —Blood-red hornbeam;

bird cherry —Prunus padus;

buckthorn —Alder buckthorn;

black currant -Ribes nigrum;

raspberry -Rubus idaeus;

local blackberries -Rubus spp.;

European euonymusEuonymus europaeus.

This zone should form a transition from open swamp to normal forest, rather than a sharp wall of trees.

4. Zone D – wet meadows and swamp periphery

Here, trees are sparsely distributed - in separate groups, strips or islands.

Suitable trees

native willow species;

alder;

downy birch;

pedunculate oak on micro-elevations;

wild apple tree -Malus sylvestris;

wild pear -Pyrus pyrasteron the drier border;

Rowan berry -Rowan tree;

bird cherry.

Shrubs

viburnum;

дёрен;

buckthorn;

local rose hips;

blackthorn —Prunus spinosaon the dry periphery;

local hawthorn species -Crataegus spp.;

currant;

willow bushes.

Tree stands should not displace wet meadows. Open areas must be preserved for pollinators, amphibians, and ground-nesting birds.

5. Trees of spring swamps

Spring bogs are particularly sensitive to shading, trampling and changes in the chemical composition of the water.

Suitable species on the periphery

black alder;

grey alder;

common ash or narrow-leaved ash - depending on the climate;

smooth elm;

native willow species;

bird cherry;

viburnum;

buckthorn.

Avoid dense planting directly above a spring outlet. Roots, fallen leaves, and fallen large trees can alter the structure of the spring outlet.

6. Trees of the swamp islands

Small tree groups can be formed on natural and artificially created islands.

For low, wet islands

alder;

willows;

downy birch;

buckthorn;

viburnum.

For higher mineral islands

English oak;

smooth elm;

ash tree;

small-leaved linden;

rowan;

wild apple tree;

hazel.

Such islands are created by:

safe nesting sites;

shelters during floods;

food base;

areas of old and hollow trees.

Some islands should be left treeless for open habitat birds.

7. Mediterranean and arid regions

For Morocco, southern Spain, Portugal and other Mediterranean territories, the Northern European list cannot be mechanically transferred.

Trees of wet floodplains

narrow-leaved ash -Narrow-leaved ash;

black alder -Alnus glutinosain suitable cool valleys;

eastern alder -Oriental alderin its natural region;

white poplar -White poplar;

black poplar -Black poplar;

white willow -White willow;

southern willow -Salix pedicellataand other local species;

oriental plane tree -Oriental plane treewhere it is naturally justified;

tamarisk -Tamarix spp.in brackish and saline areas.

Shrubs

oleander -Oleander treealong seasonal watercourses;

tamarisk shrub forms;

Vitex chasteberry -Vitex lamb-chaste;

local blackberries;

myrtle —Common myrtlein suitable damp areas;

mastic tree -Pistacia lentiscuson the drier periphery.

The European classification separately identifies narrow-leaved ash, oriental plane tree, oriental alder, oleander and tamarisk for Mediterranean floodplain forests.

8. Saltwater and coastal marshes

In brackish swamps, ordinary floodplain trees often die.

Suitable woody plants

Tamarix of local species -Tamarix spp.;

salt-tolerant forms of white poplar;

some local willows in low salinity conditions;

salt-tolerant shrubs of regional flora;

mangrove species - only in the regions of their natural distribution.

Important limitation

Coastal salt marshes often need to remain largely treeless. Massive tree planting can destroy rare halophyte communities and bird habitats.

9. The meaning of the main genera

Alder - Alnus

Main functions:

tolerates water-saturated soils;

strengthens the banks;

quickly forms a wet forest;

enriches the system with organic matter;

creates an environment for a variety of invertebrates.

Grey alder is capable of being the first to occupy damp, disturbed areas, after which other tree species may appear.

Restrictions

alder should not be planted in open swamps;

Dense alder forests can displace light-loving communities;

It is necessary to take into account alder diseases and local genetic material.

Willow - Salix

Main functions:

takes root quickly;

tolerates periodic flooding;

stabilizes the shore;

provides early food for pollinators;

easily used in living fascines and wicker structures.

Planting water-tolerant willows is widely used to stabilize banks and improve riparian habitats.

Restrictions

some species produce aggressive shoots;

large willows should not be placed close to bridges and pipes;

It is necessary to use local species, not ornamental hybrids of unknown origin.

Downy birch – Betula pubescens

Suitable for:

acidic swampy soils;

peat outskirts;

cool climate;

transition between the swamp and the forest.

Restrictions

In open, valuable peatlands, the widespread growth of birch can be a sign of drainage. In such cases, it is necessary to restore water supplies first, rather than expand the birch forest.

Poplar - Populus

Suitable for:

wide floodplains;

alluvial soils;

rapidly changing shores;

formation of high floodplain forests.

Restrictions

large root system;

fragility of individual species and hybrids;

danger to bridges, dams and communications;

Invasive or ornamental clones should not be used instead of local populations.

Ash - Fraxinus

Suitable for:

moist, but not constantly oxygen-free soils;

high floodplain terraces;

oak-elm-ash forests.

Restrictions

It withstands long-term deep flooding worse than alder and willow;

it is necessary to take into account regional diseases;

Genetic diversity and natural regeneration should be preserved.

Elm — Ulmus

The smooth elm is especially valuable.

Functions:

formation of floodplain forest;

resistance to periodic flooding;

support for insects and birds;

creation of old hollow trees.

Genetically diverse material should be used and regional elm diseases should be taken into account.

English oak - Quercus robur

Located:

on high floodplain terraces;

micro-elevations;

periphery of swamps;

areas with seasonal but not permanent flooding.

Oak is not a tree native to deep swamps. Its purpose is to form a long-lasting upper layer of transitional floodplain forest.

10. Shrubs for biodiversity

Viburnum arvensis

Gives:

flowers for insects;

fruits for birds;

dense shelters;

beautiful transition to the rainforest.

Buckthorn brittle

Suitable for:

humid forests;

peat peripheries;

acidic soils.

Important for insects and birds.

Doren

Used for:

coastal strengthening;

shrub corridors;

food base;

hedges.

Black currant

Naturally associated with damp forests and alder groves.

Suitable for:

undergrowth;

food forests on the periphery;

birds and pollinators.

Cherry tree

Valuable for:

early flowering;

birds;

shady, humid forests;

formation of the middle tier.

Hazelnut

Suitable only for drier peripheries.

Creates:

nut feed base;

shelters;

transition to a normal forest.

11. Recommended spatial structure

For a large swamp complex, the following model can be used:

This is not a universal standard. The percentage is determined by the natural type of the wetland and the target species.

12. Mixed plant communities

Alder-willow community

Suitable for:

lowland;

banks;

long-term wet soils.

Composition:

alder;

willows;

buckthorn;

viburnum;

black currant;

sedges;

ferns;

mosses.

Birch-alder community

Suitable for:

acidic peat margins;

cool climate.

Composition:

downy birch;

alder;

ash willow;

buckthorn;

Marsh myrica;

local mosses and sedges.

Oak-elm-ash community

Suitable for:

high floodplain terraces;

fertile alluvial soils;

short-term flooding.

Composition:

English oak;

smooth elm;

ash tree;

poplar;

bird cherry;

viburnum;

дёрен;

hazel on the periphery.

Mediterranean floodplain community

Composition:

narrow-leaved ash;

white poplar;

black poplar;

willows;

oriental plane tree;

vitex;

oleander;

tamarisk in more saline sectors.

13. Planting material

Priority is given to:

natural regeneration;

local seeds;

cuttings of local willows;

planting material from the same catchment area;

regional nurseries;

genetically diverse parties.

Restoration should accelerate natural succession, not replace it with artificial plantations. The FAO views facilitating natural regeneration as a way to accelerate natural restoration processes.

14. Planting and care

Willows

You can use:

living stakes;

cuttings;

fascines;

wicker fortifications;

rooted plants.

Alder and birch

Better to use:

small seedlings;

natural self-seeding;

landing on micro-elevations.

Oak, elm and ash

Landing:

on high terraces;

in small mixed groups;

with protection from grazing;

without deep soil changes.

The early years

It is necessary to control:

water level;

washing out seedlings;

animal damage;

overgrowth by invasive species;

drying out;

root condition;

natural regeneration.

15. What not to do

The following is not allowed:

plant trees all over the swamp;

plant dry-loving species in permanent water;

use one tree species throughout the entire area;

massive use of alien ornamental willows and poplars;

plant trees on valuable open peatlands;

transform a wet meadow into a continuous forest;

placing large trees near dams, bridges and pipes without calculation;

plant trees directly on emergency overflows;

use eucalyptus as a versatile swamp tree;

confuse rainforest restoration with the creation of a tree plantation.

16. Integration with DREVO Living Mountains

Trees and shrubs of marshy areas are combined with:

DREVO Mountain Sponge;

Mountain Springs Recovery;

Mountain Forest Corridors;

DREVO Living Wetlands;

DREVO Timber Reserve;

WOOD Clean Rivers;

River Rover Restore;

Living Mountain Observatory;

Mountain Digital Twin;

TREVO AeroSense Drone;

WOOD AI;

DREVO Bee Ecosystem.

Mission

The woody and shrubby vegetation of swamps should not simply increase the number of trees, but also form transitions between water, meadow, shrubs and forest.

A properly designed system includes:

willows and alders in the wettest areas;

birch and shrubs on the peat outskirts;

poplar, elm and ash in the seasonally flooded floodplain;

oak, linden and wild fruit species on high terraces;

open, treeless areas for marsh plants, amphibians and birds.

In this way, it is not a plantation that is formed, butliving swamp forest complex, capable of retaining water, supporting biodiversity and connecting the river with the surrounding landscape.

DREVO Living Mountains

Concepttree species prioritiesfor the projectDREVO Living MountainsThe main principle is not just to plant a forest, but to form itsustainable catchment, where each tree performs its own hydrological, soil-protective and ecological function.