Linden: species, characteristics and use in mixed forests

Linden trees belong to the genusTiliaFamily Malvaceae. These are deciduous trees native to temperate regions of Europe, Asia, and North America. They are distinguished by heart-shaped leaves, fragrant flowers, and a characteristic long bract connected to the peduncle. Several dozen species and natural hybrids of lindens are recognized in the world flora.Plants of the World Online)

The linden tree's primary role in the forest is not only its honey supply. It creates soft humus, supports soil fauna, tolerates shade, forms a second layer, and helps long-standing oak forests maintain a humid microclimate.

Assessment in tables:

5- very high stability;

4— high;

3- average;

2- low;

1- very low.

Maximum comparative table of lindens

View	Natural region	Height	Durability	Frost	Drought	Wet soils	Lime	City	Shadow	Height	Main feature	Best use
Small-leaved linden – Tilia cordata	Europe, Western Asia, Central Siberia	20–30 m	400–700 years, individual trees longer	5	4	3	5	4	5	Average	The most versatile European forest linden	Oak forests, second tier, shelterbelts, parks
Large-leaved linden - T. platyphyllos	Central and Southern Europe	25–40 m	400–800 years	4	2–3	4	5	3	4	Medium-fast	A large tree of fresh, rich slopes	Wet ravines, mountain forests, rich calcareous soils
European linden — T. × europaea	Natural hybrid of Europe	25–40 m	300–600 years	4–5	3	3–4	5	4	4	Fast	Hybrid of small- and large-leaved linden	Alleys, parks, estates, mixed forests
Silver linden - T. tomentosa	Southeastern Europe, Western Asia	20–30 m	200–400+ years	3–4	5	2	4–5	5	3	Average	Silvery underside of leaves, heat resistance	Cities, warm dry areas, southern slopes
Caucasian linden - T. dasystyla	Caucasus, Crimea, Northern Iran	20–30 m	300–600 years	3–4	4	3	4	4	4	Average	Heat-loving forest linden with good drought resistance	Caucasian and Southern European climate analogues
Crimean linden — T. × euchlora	A natural hybrid of Crimea and Northern Iran	15–25 m	200–400 years	4	4	3	4	5	3	Average	Clean crown, good urban stability	Streets, alleys, compact urban plantings
American linden — T. americana	Eastern and Central North America	20–35 m	200–400 years	5	2–3	4	3	3	5	Fast	Large leaves and a powerful shady crown	Cool, damp forests and large parks
Amur linden — T. amurensis	Far East, China, Korea	20–30 m	300–500 years	5	3	3–4	3	3	4–5	Average	Very frost-hardy Asian forest linden	Cold continental forests
Manchurian linden — T. mandshurica	Northeast Asia	15–25 m	200–400 years	5	2–3	4	3	3	4	Average	Large pubescent leaves, frost resistance	Cold, damp areas, arboretums
Japanese linden - T. japonica	Japan and Eastern China	15–25 m	200–400 years	4–5	2–3	4	2–3	3	4	Average	Close to small-leaved, loves a humid climate	Cool forest gardens and collections
Lipa Maximowicz - T. maximowicziana	Japan, Kuril Islands	20–30 m	200–400 years	5	2	4	2–3	2–3	4	Average	Very large leaves, cold resistant	Humid cool areas
Linden Henry - T. henryana	Central China	10–20 m	150–300 years	2–3	3	3	2–3	3	3	Slow	Young leaves with long ciliate teeth	Protected gardens with a mild climate
Chinese linden - T. chinensis	Central China	15–25 m	200–400 years	4	2–3	3–4	3	3	4	Average	Forest linden of East Asian origin	Arboretums and scientific plantings
Mongolian linden — T. mongolica	Mongolia, Northern China	8–15 m	150–300 years	5	4	2	3–4	4	3	Slow	Small, frost- and drought-resistant	Cold cities, forest-steppe, small areas

Height and age ranges vary depending on climate, planting material, soil, and care. Old linden trees often develop hollow trunks, but the tree continues to thrive thanks to the active outer wood and crown regeneration.

1. Small-leaved linden is the main species for long-lasting forests

Cordate lime tree— the main choice for Central Europe. Its natural range extends from Europe to Central Siberia and Northern Iran. In Switzerland, it is found as a native forest species. The tree reaches approximately 30 m.Plants of the World Online)

Indicator	Characteristic
Leaves	Small, usually 3–8 cm, glaucous below
Hairs	Reddish tufts at the corners of the veins
Bloom	Usually later than large-leaved linden
Flowers in an inflorescence	Usually 3-10
Fruit	Small, relatively thin-walled
Crown	Dense, rounded
Root system	At first a distinct main root, later a powerful branched system
Shade tolerance	Very high
Overgrowth	Renews well from the stump and base of the trunk

It grows on clays, loams, sandy and calcareous soils, tolerates acidic, neutral and alkaline reactions, but fresh, fertile and well-drained soils are optimal.rhs.org.uk)

Main advantages

suitable for the second tier of oak forest;

tolerates partial shade well;

relatively drought-resistant after rooting;

improves forest litter;

provides fragrant flowers for insects;

withstands periodic pruning and shoot management;

capable of living for centuries.

Restrictions

does not tolerate prolonged waterlogging well;

young plants are heavily eaten by deer and roe deer;

dense linden growth can shade oak undergrowth;

Sticky honeydew from aphids often appears under city trees.

2. Large-leaved linden - for rich, moist slopes

Tilia platyphyllos— a larger, more moisture-loving linden. It reaches about 40 m, has leaves up to 15 cm, and typically bears 2–5 flowers per inflorescence. In Switzerland, natural populations are primarily associated with warm valleys and the southern part of the country, although the species is widely planted.infoflora.ch)

Parameter	Peculiarity
Soil	Deep, rich, often carbonate
Humidity	Higher than required for small-leaved linden
The best relief	Ravines, northern and eastern slopes, foothills
Drought	Tolerates worse than small-leaved
Frost	High resistance, but somewhat lower than T. cordata
Ecological role	A large tree of humid mixed forests

Best companions:

sycamore;

ash tree;

rough elm;

beech;

English oak;

hazel;

elderberry;

viburnum.

For dry, open, southern slopes, large-leaved linden is usually inferior to field maple, small-leaved linden, or silver linden.

3. European linden is a powerful natural hybrid

Tilia × europaeawas formed by crossing small-leaved and large-leaved lindens. This hybrid is recognized as a natural European taxon. (Plants of the World Online)

Its features:

faster growth;

large crown;

good tolerance to urban conditions;

active formation of shoots around the trunk;

suitability for alleys;

intermediate moisture requirements.

The disadvantage is the abundant basal shoots and a very large crown. It's an inconvenient choice for a small plot.

4. Silver linden – for the heat and the city

Tilia tomentosaIt is native to Southeastern Europe and Western Asia. In Switzerland, it is mainly cultivated, and in the south, it occasionally grows wild.infoflora.ch)

The main distinguishing feature is the whitish-silvery, felt-like underside of the leaf.

Advantages

tolerates heat better than many linden trees;

relatively resistant to summer drought;

The reflective underside of the leaves reduces overheating;

grows well in the city;

forms an even decorative crown;

less attractive to some sucking insects than common urban linden trees.

Restrictions

less frost-resistant than small-leaved linden;

not intended for cold, swampy areas;

as an alien species it should not displace local linden trees in the natural forest;

A large tree requires a lot of space.

For warm cities and climatically dry areas, it is often more practical than large-leaved linden.

5. Crimean linden is a good outdoor hybrid

Tilia × euchlora— a hybrid of small-leaved linden and Caucasian linden. Its natural origin is associated with Crimea and northern Iran.Plants of the World Online)

Peculiarities:

more compact and neat crown;

shiny leaves;

less basal shoots than the European hybrid linden;

good resistance to urban conditions;

comparatively high heat and drought resistance;

suitability for streets and alleys.

For natural reforestation, native species are better, but for urban landscaping this is a useful hybrid.

How to distinguish the main European lime trees

Sign	Small-leaved	Large-leaved	Silvery	European hybrid
Sheet size	Small	Large	Medium or large	Intermediate
Top of the sheet	Usually smooth	Often slightly pubescent	Dark green	Volatile
A series of leaves	Bluish	Green, hairy along the veins	White-felt	Intermediate
Hairs in the corners of the veins	Reddish	Whites	The entire underside is pubescent	Changeable
Tsvetkov	Usually 3-10	Usually 2-5	Usually 5-10	Intermediate
Fetus	Easier to crush	Firm, with pronounced ribs	Solid	Volatile
Bloom	Later	Earlier	Later	Average
Drought resistance	High	Medium-low	Very high	Average
Shade tolerance	Very high	High	Average	High

The ecological role of linden

1. Improving humus

Linden leaves contain relatively many bases—calcium, magnesium, and potassium—and usually decompose faster than coarse oak or beech litter.

In a mixed oak forest, linden helps:

reduce the accumulation of dense acidic litter;

support earthworms;

accelerate the processing of organic matter;

return minerals to the upper horizons;

form soft forest humus.

Therefore the combinationoak + lindenecologically stronger than pure oak planting.

2. Support pollinators

The fragrant flowers provide nectar and pollen to bees, bumblebees, hoverflies, and other insects. Different linden species bloom at slightly different times, so combining them can extend the period of food availability.

However, linden trees shouldn't be the only source of honey. During droughts, nectar production decreases, and a large number of insects can congregate on a limited resource.

3. Maintaining the microclimate

Dense crown:

shades the soil;

reduces evaporation;

protects oak trunks from sunburn;

reduces the temperature under the canopy;

retains air humidity;

creates a shadow second tier.

4. Regeneration of shoots

Linden regenerates well after damage or felling. This makes it valuable for:

forests damaged by storms;

slopes;

protective strips;

traditional coppice forestry;

long-term preservation of forest cover.

Soil and planting conditions

Condition	The most suitable linden tree
Ordinary fresh forest soil	Small-leaved
Dryish calcareous soil	Small-leaved
Rich wet slope	Large-leaved
Hot urban area	Silvery
Street and alley	Crimean, silver, varietal small-leaved
Cold continental climate	Small-leaved, Amur
Cool, humid climate	Large-leaved, American, Japanese
Southern warm slope	Silver, Caucasian
Deep shadow of a young forest	Small-leaved
Heavy clay	Small-leaved, if there is no stagnant water
Limestone	Small-leaved, large-leaved
Acidic soil	Small-leaved tolerates, but develops better in richer soil
Floodplain with short-term moisture	Large-leaved or small-leaved on micro-elevation
Constant waterlogging	Linden is undesirable; alder and willow are better
Salty sea coast	Only in the protected second or third row

Soil requirements

Optimal profile:

the depth of suitable soil is preferably at least 80–120 cm;

good aeration;

moderate moisture capacity;

no prolonged stagnation of water;

a neutral or slightly alkaline reaction is particularly favorable;

the presence of organic matter, but without adding fresh manure to the planting hole.

Small-leaved linden can grow on chalky, clayey, sandy and loamy soils with good drainage. (rhs.org.uk)

Compatible with oak, ash and maple

Main tree	Compatibility with linden	Benefit	Possible conflict
English oak	5/5	Improves humus, protects the trunk, retains moisture	A linden tree can shade a young oak tree.
Sessile oak	5/5	Suitable for dry slopes	On very dry peaks, linden trees may not have enough water.
Downy oak	3–4/5	Useful in fresher soil pockets	Common linden is less drought-resistant.
Common ash	5/5	Forms a rich, multi-layered forest	Both species require fertile soil.
Field maple	5/5	Strong second tier, fast humus	May become too dense with undergrowth
Sycamore	4/5	Good on wet slopes	Together they are capable of strongly shading the lower tier.
Maple tree	4/5	A good urban and forest complex	Dense general shadow
Hornbeam	5/5	Stable second tier	Periodic windows are needed for oak undergrowth.
Elm	5/5	Rich ravine and slope forests	Requires monitoring of the condition of elms
Beech	3/5	Possible in damp mature forest	Beech can gradually displace linden and oak by light shading.

The best companion trees for linden

Satellite	Function
Oak	Durable upper frame
Ash tree	Light crown and fast mineral exchange
Hornbeam	Second tier and trunk protection
Field maple	Humus and filling of forest edges
Sycamore	Wet slopes and ravines
Elm	Deep rich soils
Merry	Flowers, fruits, temporary forest windows
Bereka	Dry limestone areas
Rowan	Fruits for birds and a cold-resistant second tier
Birch	Temporary pioneer canopy
Alder	Only in damp depressions

Shrubs for linden undergrowth

Bush	Conditions	Role
Hazelnut	Fresh fertile soil	Nuts, undergrowth, soft litter
Hawthorn	Light edge	Flowers, fruits, protection of young plants
Blood-red dogwood	Calcareous soils, partial shade	Fruits and slope strengthening
European spindle tree	Rich forest soil	Fruits, undergrowth structure
Viburnum	Wetter places	Fruits and dense, damp undergrowth
Black elderberry	Nitrogen-rich areas	Fast processing of nutrients
Privet	Warm, dry forest edges	Thick protective belt
Forest honeysuckle	Penumbra	Flowers, fruits, shelter
Rose hip	Light edges	Pollinators and fruits
Turn	Outer edge	Protection and early flowering
Buckthorn	Acidic damp areas	Food for insects and birds
Holly	Mild humid climate	Evergreen winter undergrowth

Recommended layout around oak

Linden is especially useful as a "nurturant" tree next to oak.

Element	Accommodation
The main oak	Group center
Linden trees	2–4 trees 6–10 m from the oak
Field maples	In the middle and outer tiers
Hornbeam	From the north and east sides
Ash tree	In a light, damp sector
Hazelnut	8-15 m from the center
Hawthorn and red	On the outer edge

The linden tree should cover the side of the oak trunk, but not its crown. When the linden crown begins to compete with the oak's top, it is thinned out or formed into a second tier.

Landing distances

Landing type	Estimated distance
Linden as a large free tree	10–15 m
Linden in a mixed forest	5–8 m at the start
Linden tree next to oak tree	Preferably 6-10 m
An alley of large linden trees	8–12 m
A narrow alley of compact varieties	5–8 m
Linden protective strip	2.5–5 m with subsequent thinning
Coppice group	2–4 m between parent plants

The forest planting may be denser than the final structure. Subsequently, some trees are removed or transferred to the second tier.

Diseases and pests

Linden trees are generally considered relatively resilient, but are not completely problem-free.

Problem	Manifestation	Risk conditions
Phytophthora root rot and bleeding ulcers	Root death, darkening and discharge on the bark	Waterlogging, compacted soil
Verticillium wilt	Wilting of individual branches or the crown	Contaminated soil, weakened trees
Aphid	Sticky honeydew on leaves and objects under a tree	City alleys, dry air
Gall mites	Red or green growths on leaves	Usually a decorative, non-dangerous problem
Leaf spots	Spots and early leaf fall	Wet weather
Mistletoe	Weakening of branches due to severe infestation	Old city trees
Deer damage	Eating young animals and shoots	Unprotected forest plantations

Forest Research notes the risk of root infections and bleeding cankers associated with late blight, as well as the rare but potentially fatal verticillium wilt, for small-leaved linden. Young plants and shoots are particularly attractive to deer.Forest Research)

Priority for Switzerland and Central Europe

Priority	View	Recommended role	Share among all trees
1	Small-leaved linden	The main second tier, oak forests, dry forest edges	7–15%
2	Large-leaved linden	Fresh slopes, ravines, mountain forests	3–8%
3	European hybrid linden	Parks, alleys, cultural landscape	1–4%
4	Silver linden	Hot Cities and Future Climate Tests	1–5%
5	Crimean linden	Streets and compact alleys	Limited
6	Asian and American species	Arboretums and scientific testing	Less than 1-2% of each

For the natural forest of the Zurich Oberland region, it is reasonable to form the basis fromlocal small-leaved linden, and large-leaved linden should be planted on wetter and richer slopes. Silver linden is best used primarily in urban areas or in warm experimental sites.

The optimal role of linden in the forest DREVO

Linden should be considered assoil-climatic architect of the second tier:

oak creates a durable frame;

Ash provides light and rapid exchange of minerals;

maple fills the forest windows;

Linden stabilizes humus, humidity and shade microclimate;

hornbeam regulates the density of the lower canopy;

The bushes form a protective edge.

For a typical mixed broadleaf forest, a reasonable total proportion of linden trees is approximately10–20%, but not uniformly across the entire area. In dry oak areas, small-leaved linden dominates, in damp ravines, large-leaved linden, and in hot urban areas, silver linden.

Illustration из исходного документа — Illustration 37