How big are tree roots


How Wide Do Tree Roots Spread?

“Most tree roots…occupy an area two to four times the diameter of the crown.”
– Colorado State University Extension

“Roots may occupy an area four to seven times the surface area occupied by the crown of the tree.”
– Iowa State University Forestry Extension

“While one rule of limb has been that a tree’s roots are one and one-half to three times wider than the foliage, other investigators estimate an irregular root pattern four to seven times the crown area; and, still other researchers maintain that the root extension can be four to eight times wider than the dripline of the tree, but only under certain conditions.”
-Roots Demystified, Chapter 9,  Robert Kourik, 2008. (He did his research for this chapter at the UC Agricultural Libraries at Berkeley and Davis in the late 1980s)

Well, that’s clear as mud! How can we protect roots from development (or development from roots, for that matter) if we don’t know where the roots are… or, even worse, if the roots may be everywhere?

The roots of this oak tree (left) are certain to be found in the neighboring property (right)

Some facts from the 4th edition of Arboriculture (Richard Harris, James Clark and Nelda Matheny) can make it easier to predict where roots might be:

  • Roots are opportunistic. There will be more roots when conditions are favorable. Fertile, moist, uncompacted soils will have more fibrous roots.
  • In dry, compacted soils with no organic matter, roots are fewer but larger and able to grow further distances from the plant.
  • Open-grown trees often have a wider root system than trees closely planted together. Some species, such as Coast redwood (Sequoia sempervirens) can root-graft with others of their kind, sharing nutrients, stabilizing each other and reducing the stress on each individual tree.
  • Root systems may grow wider when downward growth is restricted, such as by a high water table or perhaps bedrock.

However, roots can always surprise you, and direct inspection is always required to be sure where roots are.

Roots found during construction

Ultimately, comparing the spread of the root system to the spread of the canopy is problematic. The dripline is easily altered by pruning, and the roots will not shrink to match the pruned canopy. Trunk diameter is a more reliable predictor of root spread. A 2009 study by Susan Day and Eric Wiseman at Virginia Tech analyzed young trees less than 8 inches in diameter growing in unobstructed soil and found that the ratio of root radius to trunk diameter was about 38 to 1. For example, a 6-inch tree could have roots out from the trunk as far as 19 feet. Studies for mature trees are fewer, but suggest that this ratio is smaller for older trees.

Site plan with tree protection zones (TPZs) drawn on plan

Arborists typically use trunk diameter to determine a root protection zone during development.  A common guideline recommends a tree protection zone with a radius of one foot for every one inch of trunk diameter – a 12 to 1 ratio. It’s important to stress that this is just a guideline. The size and location of the tree protection zone varies by species, age and condition of the tree as well as soil type and the nature of the surrounding existing development.

Hand-digging can preserve roots when trenching. Here, a hand-dug trench means an irrigation line can be successfully laid under established tree roots.

A Project Arborist should be retained in the planning stage to assess trees, review plans and look for roots in the proposed development area. Trenching or pot-holing in selected sites using an air or water excavator can expose roots with less damage than traditional excavation methods. By finding exactly where tree roots are located in advance, the project can be designed with tree preservation in mind.

Ellyn Shea is an arborist and consultant in San Francisco.

Threthny / CC BY 2.0

How Deep Do Tree Roots Really Grow?

Our 2010 blog entry by James Urban, FASLA, on the topic of how deep tree roots grow is consistently one of our most popular. Obviously there is a curiosity about this topic and a need for useful data about it. But the original post is a little technical and not as image-heavy as we’d like. So today we’re bringing you a new and improved version of the original post, with additional pictures and more simplified explanation of the factors that really influence how deep tree roots grow.  

How deep tree roots grow depends on three simple factors. To answer this question I contacted Jim Urban, FASLA, a noted tree and soil expert. He contributed to the following post.

Roots require three things: water, oxygen, and soil compaction levels low enough (or with void spaces sufficiently large enough) to allow root penetration. If all these conditions are met, roots can grow to great depths. Under ideal soil and moisture conditions, roots have been observed to grow to more than 20 feet (6 meters) deep. 

Early studies of tree roots from the 1930s, often working in easy-to-dig loess soils, presented an image of trees with deep roots and root architecture that mimicked the structure of the top of the tree. The idea of a deeply-rooted tree became embedded as the typical root system for all trees. Later work on urban trees that were planted in more compacted soils more often found very shallow, horizontal root systems. Urban foresters have successfully spent a lot of energy trying to make people understand that tree roots have a basically horizontal orientation, to the point that even many tree professionals now believe that deep roots in trees are a myth. The truth lies somewhere in between deep roots and shallow roots.

This totally horizontal root system formed on top of poorly drained soils. Photo courtesy of Miles Barnard.

Simply put, by Jim: “Trees are genetically capable of growing deep roots, but root architecture is strongly influenced by soil and climate conditions.”

The most typical limitations to tree rooting in urban areas are soil compaction and poor drainage. These are often related, with a compaction layer creating a poorly-draining hard pan. This results in a perched water layer that restricts roots. Hard pans and perched water tables can also be found in nature. In fine-grained clay soils and fine-grained silty soils, pore space — and therefore and rooting depth — is often limited. Since these conditions are quite common in urban areas, shallow rooted trees are often seen as “typical.”

Six foot long sinker or striker roots in well-draining soils. Note the remnant of horizontal roots at the trunk flare. Photo courtesy of Miles Barnard.

Orjan Stahl, a tree researcher in Stockholm, made an exhaustive study of over 500 trees that had root and utility conflicts. He regularly found roots at depths of 7 to 9 feet (2.1 to 2.7 meters) and the deepest root he encountered was at 23 feet (7 meters). In their 1991 paper, “On The Maximum Extent of Tree Roots,” E.L. Stone and P.J. Kalicz summarized previous root depth studies of 49 genera and 211 species growing in a wide variety of soil types. They found numerous examples of trees reported to be growing roots to over 33 feet (10 meters), and one report of a tree that grew roots to a depth of 174 feet (53 meters). Clearly, a tree’s ability to grow deep roots is not a significantly limiting factor in soil design.

4 foot deep rooting in loam soil that was on top of a hard pan. Photo courtesy of James Urban.

Given all this, and the unpredictable site constraints of the urban environment, urban trees need flexible solutions that can enable roots to grow out or down. In some sites, increasing soil depth is not a problem, while expanding may be limited by other constraints. The opposite can also be true. This is why the Silva Cell system is flexible in all three dimensions to respond to different spatial limitations.

These roots go at least 4 feet deep. This tree fell over after the irrigation contractor installed a line on the up wind side. Photo courtesy of James Urban.

The designed maximum depth of the system is 45 inches (1150mm). This is a strategic compromise between the system’s structural requirements, soil volume, and cost and constructability issues. The Silva Cell was designed to provide a deep soil volume because roots will grow to these depths. For urban sites where deep excavation is limited, one- or two-layer systems can provide the same total soil volume across a shallower profile.

Two other factors are absolutely critical to the ability of roots to grow though the entire soil profile: the type of soil that is used, and designing the system to permit adequate water into and to drain out of the soil. These features must be designed to reflect the environment in which the Silva Cells are to be placed, the types of soil resources available and the project performance expectations of trees, soil and water.

Horizontal rooting to about 4 foot depth in loam soil over river wash till. Photo courtesy of James Urban.

Root systems of hardwood trees

Silver birch . It is widely distributed in the European part of our country from the southern regions to the borders of the forest tundra.

It usually occurs as an admixture to broad-leaved or coniferous species in various combinations in various types of forest conditions. Despite its wide distribution, the morphology of the birch root system has not been well studied until recently.

In the conditions of a fresh dry oak forest on medium-soddy medium podzolic soils in pine-birch plantations of class I of bonitet, with a density of 0.8, birch roots have 10-15 well-developed horizontal roots of the first order, forming a dense network of skeletal, semi-skeletal and suction roots. At the age of 27, the length of the horizontal roots of the first order reaches 8.05 m, the diameter is 13.6 cm.5-115 cm. Most trees have a large number of well-developed vertical branches from horizontal roots, some of which penetrate the soil to a greater depth than taproots. However, some trees show a complete absence of vertical branches. The length of the skeletal roots of horizontal orientation and their branches depends on the growth group of the tree.

Compared to other species, birch has the highest branching coefficient - 17.2 (pine 3.0, oak 1.5, spruce 5.6, maple 1.8). The projection area of ​​the root systems is 33.1-46 m 2 , volume of soil occupied by roots, 11.0–43.7 m 3 depending on the tree growth group.

The intensity of the root population of the occupied volume of soil in different trees is different - from 19.1 to 111.1 m/m 3 , i.e. 1.8-2.6 times more than in pine. The average annual increase in the volume of soil occupied by the roots reaches 4. 1 m 3 , in the total length of the roots 15.4 m 3 , in the surface of the suction space of the roots 9.1 dm 3 .

Common hornbeam . Usually, under natural conditions, the hornbeam does not form pure stands, but its importance as a companion species is great. Widely distributed in broad-leaved forests of the southwest of the European part of the USSR. It is characterized as a breed with a powerful superficial root system.

In the root system of the hornbeam in 15-year-old oak-hornbeam cultures in the conditions of the Vinnitsa region on gray forest soils (the type of forest conditions is fresh oak forest), horizontal roots predominate.

However, at the same age, well-developed taproots are often found, having a high degree of branching and penetrating to a depth of 1.9 m. Horizontal roots of the first order reach a length of 5.9 m. The degree of branching is high, there are skeletal roots of the seventh-eighth orders branching. In the total length of the roots, roots of the second order of branching prevail, in the total mass - of the first, and in terms of the number of branches - of the third order of branching.

Forest beech . On the territory of the USSR, beech naturally grows in the Kaliningrad region, in the Carpathians and Precarpathians, Kodry of Moldova and in the Crimea. The structure of the root system of the forest beech, as well as white fir, has not been studied enough.

As in spruce, the root system of beech in 11-22-year-old spruce-beech-fir cultures in the conditions of the Carpathians at an altitude of 750-1000 m above sea level. m. has a pronounced surface structure.. The taproot at the age of 11-22 years of trees is usually absent. It transforms into a short thickening, which is a continuation of the tree trunk.

The relative participation of horizontal roots in the total length of the skeletal roots is 99.2–99.96%, in the total mass of the root system 70.1–73. 2%. Individual trees may have 3-4 vertical branches, some of which have intensive branching and penetrate deep into the soil through crevices up to 160 cm. penetrates rocks up to a depth of 241 cm.

Beech roots of the first order are characterized by strong tapering at the base. Then, at a distance of 0.1 length, their diameters decrease relative to the length more moderately, and the roots acquire a more pronounced cord-like shape. The nature of the taper of the root is expressed by the following shape coefficients in relative lengths: 0.1-62.3; 0.2–50.4; 0.5–27.8; 0.7-16.5; 0.9-7.9%. The coefficients of the form and coefficient of the root volume (0.1800) indicate a relatively small taper of beech skeletal roots.

The projection area of ​​the root system in trees of the best growth at the age of 22 is 60.6 m 2 (for medium trees 21.2, for stunted trees 10.5 m 2 ). The volume of soil space occupied by root systems at this age in trees of the best growth is 36. 4 m 3 , medium 12.7, stunted 3.2 m 3 . The coefficient of compactness of the root system, respectively, is 14.3; 16.6 and 20.6 m/m. These figures are slightly higher than European spruce.

Pedunculate oak . It grows within its natural range in the middle and southern zones of the European part of the USSR, in the Crimea and the Caucasus. Within such a wide range, the oak is found in various types of forest conditions and forest types. Being a species demanding on soil fertility, oak under natural conditions forms mixed plantations on soils that represent a relatively wide range both in terms of fertility and the nature of moisture. However, under certain edaphic conditions, it can have III-IV bonitet classes, forming a second tier in mixed stands on dry, poor sandy soils. In more favorable conditions, it enters the first tier, reaching the II or I class of bonitet, and on rich, well-moistened soils - I and Ia classes of bonitet.

The best conditions for the growth of English oak are fresh and moist gray forest loams, degraded chernozems, powerful brown mountain forest soils. Under the influence of soil conditions, structural features of the oak root system are formed. Possessing the ability to form a powerful taproot from the very first years, oak forms a surface root system on soils with excessive moisture, with relatively insufficient moisture gives well-developed vertical branches from horizontal roots, on soils with compacted horizons such as ortstein forms a second tier of roots above its surface .

In the root system of oak on ordinary low-humus chernozems with signs of southern chernozem, vertically oriented roots predominate in oak-ash cultures. Vertical branches begin to appear at the age of 10, but by the age of 18 they make up about 20% of the total length of the horizontal roots. Horizontal roots are slightly branched. The highest relative participation is made up of skeletal roots of the first order. The branching of the tap root is more intense compared to the horizontal roots.

The depth of penetration of the taproots of oak reaches 4. 05 at the age of 10 and 4.86 at the age of 18. The development of vertical branches from horizontal roots is intensive. Some of them exceed the tap root in diameter and length, reaching a depth of 250-280 cm. The main number of roots is located in the upper soil horizons. In trees of the best growth, up to 83.8% of horizontal skeletal roots are located at a depth of up to 20 cm, 95% - in a 0-40 cm soil layer.

On degraded chernozems, a more superficial oak root system is formed. The relative contribution of roots of horizontal orientation is 13–20% greater, with a corresponding decrease in the number of vertical branches and taproots. At the same time, there is a significantly greater branching of horizontal and taproots, despite the fact that the greatest relative participation is retained by the roots of the first order of branching. The depth of penetration of the tap root into the soil is sharply reduced. It is 9 for trees of the best growth.-year-old age 167 cm, 16-year-old 183, 18-year-old 195 cm. This is more than 2 times less than the depth of penetration of roots of English oak on ordinary chernozems with low humus in the southern steppe.

On gray forest soils in fresh types of forest growth conditions in the structure of the oak root system, the relative participation of vertical branches is 2–2.5 times greater than on degraded soils, and almost 3 times greater than on ordinary chernozems. The intensity of development of horizontal roots and taproot is much higher here than on degraded and ordinary chernozems. The total length of skeletal roots under these conditions is already several times greater at the age of 10 than in trees 16–19-years of age under the previously considered conditions. The depth of penetration of the tap root on gray forest soils reaches 190 cm at the age of 10, and 555 cm at the age of 25, which is much greater compared to other soil varieties. Vertical branches are also intensively developed and reach a depth of 215 cm already at the age of 10 years. Therefore, fresh forest loamy soils are most favorable for the growth of English oak.

Some changes in the structure of root systems in comparison with the gray forest soils of the Right Bank of Ukraine and chernozems are observed in the conditions of soddy-podzolic and gray forest soils in the western part of the forest-steppe. The overall intensity of the development of root systems here is less than on the chernozems and gray forest soils of the Right Bank. The tap root develops much more weakly, the growth of which deep into the soil here is prevented by compacted soil horizons of an ortstein character with signs of gleying. The penetration depth of the taproot reaches 160 cm on soddy-podzolic soils at the age of 14, and 220 cm on gray forest soils.

The root systems of older trees are fully formed at the last stage of their development. The horizontal roots of an oak tree at the age of 90 (plantation class I of bonitet, medium soddy-weakly podzolic light loamy sandy soil on fluvioglacial deposits) are represented by powerful roots of the first order, located near the soil surface at a depth of up to 30 cm. From the tap root at a depth of 32–60 cm 11 roots of horizontal orientation depart.

The branching intensity of the roots is rather weak, the largest number of branches is of the third order. Horizontal roots form a network of cord-like roots located at the very surface of the soil. The length of the most developed root of the first order is 22.4 m. The total length of skeletal superficial horizontal roots with branches up to the fifth order is 1995 m, depth 207.9 m. Surface horizontal roots have vertical branches up to 113 m long, which is about 5% of the total length of these roots. Deep roots of horizontal orientation are characterized by weak development. The greatest relative participation in this category of roots is the roots of the second order.

A feature of deep roots of horizontal orientation is their ability to form vertical branches, which can be directed not only deep into, but also up to the soil surface. Superficial horizontal roots have a well-pronounced plank-shaped, at the base of the root their vertical diameter can exceed the horizontal by 5-8. 5 times. The difference in the size of the vertical and horizontal diameters disappears at a distance of 60-140 cm from the base of the root, depending on its size. Deep horizontal roots do not have plank.

The tap root of a 90-year-old oak tree has many branches of large diameter, strongly intertwined and almost completely fused in the upper part. Anchor roots, formed in close proximity to the tree trunk, intertwine and grow together with the tap root and its branches. The depth of penetration of the main root is 178 cm, anchor - up to 250 cm.

The length of the countable elements of this intergrown system is 17.8 m. The total length of the core part of the root system and the vertical branches from the taproots is approximately 130 m, or 5% of the total length of the skeletal roots.

In oak, as in other tree species, the roots of horizontal orientation mainly participate in the root system, most intensively developing the upper soil horizons within 0–60 cm. At the same time, oak has the ability to form deep-reaching and highly developed taproot. Its ability to form vertical branches from horizontal roots is somewhat less than that of many tree species (pine, walnut, chestnut, linden, spruce). The branching intensity of oak roots is weak, and no significant variation of this trait under the influence of soil conditions has been established.

The average coefficient of branching of oak roots is expressed as 1.46, which is lower than its value obtained for other tree species. The intensity of taper of skeletal roots of oak is determined by the coefficients of the shape of the root at relative lengths: 0.1 - 72.4 ± 0.55; 0.2 — 56.2±0.63; 0.5 - 29.8±0.54; 0.7 - 16.7±0.4; 0.9-7.4+0.20. The coefficient of volume of the horizontal skeletal roots of oak is 0.1851, which indicates a large cord-like nature of its roots compared to other species.

Projection areas of oak root systems can reach 50 m 2 by the age of 19, more than 60 m by the age of 25 2 . The excess of the area of ​​projections of root systems over the area of ​​projections of crowns is from 5. 4 to 8.4. The large depth of penetration of the roots into the soil provides the oak with the rapid development of significant volumes of soil space, which makes the indicator of compactness of its root system, which is in the range of 1.9-10.8, exceptional.

Large-leaved linden . Widespread in the forests of the European part of the USSR. Grows on a variety of soils, preferring richer, fresher forest growing conditions. It performs in natural plantations and is used in cultures as a companion species with oak, pine, larch, as a rule, forms the second tier, and in less favorable conditions - the third.

The root system is well developed. In its structure (in 12-year-old cultures, on gray forest loamy soils), the roots of horizontal orientation are 78.6–93.6%. In a tree of better growth, a taproot is absent; in an average and stunted tree, it occupies 3.1 and 9.9% of the total length of skeletal roots. The branching of skeletal roots is limited to the formation of third-order roots. Vertical branches from horizontal roots are 3.6–11.2%.

The structure and structure of the linden root system testify to its superficial location. The penetration depth of the roots is 40 cm in the tree of the best growth due to the deepening of the horizontal roots. This 40 cm layer of soil contains all 100% of the roots of the best growing tree. The tap roots of trees of medium height and lagging in growth reach a depth of 80 and 70 cm. The average annual growth of the largest horizontal root is 21.7, the average is 14.3 cm. 40.8 and 15.7, silver birch 35.4 and 27.1, Scots pine 0.43 and 16.3, English oak 28.9and 17.5 cm).

The branching intensity of linden roots is medium. It is characterized by a branching coefficient of 2.1. This is somewhat higher than that of sycamore maple (1.8) and oak (1.5), but significantly less than that of other co-growing species (pine 2.5, birch 17.2).

Tapering of linden roots is determined by shape coefficients on relative lengths: 0. 1 - 0.657±0.016; 0.2 - 0.472±0.017; 0.5 - 0.330±0.018; 0.7 - 0.220±0.012; 0.9 - 0.104±0.04. The root volume coefficient is 0.1701, which corresponds to the average value among other tree species.

The projection area of ​​the linden root system is smaller than that of other species: the tree of the best growth is 9.3 m 2 , the average 10.0, the stunting 1.3 m 2 . The volume of soil space occupied by the root system, respectively, is 2.2; 2.7; 0.3 m 3 . The coefficient of compactness of the root system is very high. For a tree of the best growth, it is 37.7, for an average tree it is 19.1.

Norway Maple . Like oak, maple is widely distributed in the forests of the European part of the USSR. However, the biometric characteristic of the maple root system is poorly understood. When growing together in oak cultures, Norway maple has a well-developed root system, consisting of a tap root penetrating 3 m deep into the soil, and strong horizontally oriented roots. The intensity of the root population of the upper soil horizons in maple is almost not inferior to that in English oak.

Sycamore maple . It grows in the Carpathians as an admixture in spruce, beech and fir forests. At the same time, it is widely distributed in the lowland forests of the Carpathian region. The wood of this species is of great economic value.

Sycamore maple has well-developed taproots and horizontal roots. Horizontal roots have branches of the third and fourth orders. The roots of vertical orientation are represented by the tap root and its branches of the second and third orders. The main mass of roots on brown mountain forest soils is located in a 0–30 cm layer, however, individual taproots penetrate to a depth of more than 1 m. In sycamore, as in other species, roots of a horizontal orientation predominate in the total length of the roots (81.2 -99.2%), while the participation of the taproot in the total mass of roots in sycamore is much greater. The roots of the second or third order predominate in the total length of the sycamore roots.

The length of skeletal roots in sycamore is less than that of spruce, fir and beech, but in contrast to them, this breed has more intensively developed taproots and vertical branches from horizontal roots.

Differences in soil conditions are reflected in the structure and structure of root systems. On deep gray forest soils, the relative share of the tap root in the total length is significantly greater than on brown mountain forest soils of medium thickness, and the length of the tap root with branches on gray forest soils is 2.5–8 times greater. Under these conditions, the vertical branches from the horizontal roots are also more intensively developed. The maximum penetration depth of the tap root on brown mountain forest soils is 120 cm, on gray forest soils at the age of 12 in trees of medium height - 123 cm, the best - 510 cm.

Tapering of horizontal roots of sycamore maple is characterized by the following shape coefficients according to relative root lengths: 0. 1 — 67.3±0.01; 0.2 - 46.0+0.01; 0.5 - 24.4±0.07; 0.7 - 16.2+0.01; 0.9 - 9.2±0.003. The volume factor for horizontal roots of the first order is 0.1444. According to the intensity of taper, sycamore roots occupy a middle position among the tree species presented in this textbook. The branching intensity of the sycamore maple roots is very low (the average branching coefficient is 1.8).

The maximum value of the average annual growth along the length of the horizontal root of the first order is 21.7 cm, the average growth is 14.8 cm, the average annual growth of the tap root is 6.7 cm. The ratio of the intensity of growth of the tap root and the average horizontal root is 0.47 on gray forest soils .

The area of ​​projections of the root system by the age of 18 on brown mountain forest soils reaches 20.4 m 2 , on gray forest soils at the age of 12 11.2 m 2 , which corresponds to the projection area of ​​the roots of 14-year-old trees (11.5 m 2 ) on the brown soils of the Carpathians.

The root system of the sycamore maple on deep gray forest soils is not very compact. Thanks to the tap root, which intensively penetrates deep into, the root system relatively quickly occupies a vast amount of soil space. At the age of 12, under these conditions, the volume of soil occupied by root systems is 19 for a tree of the best growth..3 m 3 , medium 18.9 and lagging 1.1 m 3 ; coefficient of compactness of root systems, respectively, 2.6; 2.9 and 2.9 m/m 3 . However, this figure increases by 10 or more times on medium-thick brown mountain forest soils, where for trees of the best growth at the age of 8 it is 36.3, at 12 years old 26.3 and at 17 years old 23.2 m / m 3 .

Walnut . It grows in natural forests in the mountainous regions of Kyrgyzstan. Widely cultivated in Central Asia, the Caucasus, Ukraine, Moldova and southern Belarus. Prefers fresh and moist rather rich soils (chernozems and gray forest soils). By the age of 6, on gray forest soils, the walnut has not only well-developed taproot and horizontal roots, but also a significant number of vertical branches. The depth of penetration of tap roots at this age is, depending on the tree growth group, 273, 241 and 194 cm. Branches from the taproot are evenly spaced along its entire length. The total length of vertical branches from roots of horizontal orientation is 6.9–12.3% of the total length of skeletal roots. Each tree has 8-10 vertical branches. Their penetration depth also varies depending on the tree growth group. So, in trees that are lagging behind in growth, it is 49–67 cm, trees of medium height 82–124, the best 120–241 cm..5 mm.

The branching of the roots is quite intense: 420-820 skeletal branches. The highest order of branching at this age is the fourth, but there are very few roots of this order (0.3-0.9%). The main relative participation in the total length of skeletal roots is taken by the roots of the second order of branching (39. 1–55.8%).

In the total length of the skeletal roots of the walnut, vertical branches from horizontal roots take a significant relative part. The compactness of root systems is insignificant.

The walnut is distinguished by a high intensity of root growth in diameter, reaching 0.95 cm at the roots, and 1.05 cm at the taproots. which exceeds the area of ​​projections of crowns, respectively, by 2.9; 3.9 and 5.5 times.

Root taper is characterized by the following coefficients of root form at the corresponding relative lengths: 0.1 - 56.5; 0.2 - 35.1; 0.5 - 26.1; 0.7 - 18.7; 0.9- 11.4. Root volume coefficient 0.1207.

Common hazel . It is widely distributed in the European part of the USSR as an undergrowth species. Within its natural range, it occurs in fresh and moist hygrotopes on chernozem, burozem, gray forest, soddy-podzolic soils with high fertility.

The root system of hazel in the conditions of western Ukraine on soddy weakly podzolic light loamy soils in fresh hornbeam sudubrava in 90-year-old pine forests of Ia quality class is as follows: taproots are absent, horizontal ones have high branching. The total length of the skeletal roots of one bush reaches 256 m, of which the roots of the first order of branching are 8.7, the second 40.8 and the third 50.5%. The total number of branches in the most developed bushes is 850, including the first order 1.1, the second 21.9, third 77.1%. The coefficient of branching of the roots is high - 7.8. The taper of the roots of the first order is characterized by the shape coefficients at relative lengths: 0.1-0.54; 0.2 - 0.38; 0.5 - 0.25; 0.7 - 0.174 and 0.9 - 0.14. The coefficient of volume of skeletal roots of the first order is 0.1224.

The main mass of hazel roots is located at a depth of 0-30 cm, however, individual roots penetrate as deep as 60 cm.0011 2 . Despite this, the coefficient of compactness of the root system is 28.3%. Thus, the root system of hazel rather intensively inhabits the upper soil horizon in plantations.

Edible chestnut (sowing) . Chestnut edible (sowing), European, or noble, naturally grows in the Caucasus, and is also widely distributed in the Carpathians, forming a highly productive valuable tree stand in cultures. Chestnut forms a deep root system due to large roots going obliquely into the depth of the soil. The tap root is missing. The root systems of 10-year-old trees in chestnut cultures with the participation of English oak on the Carpathian brown mountain forest soils consist of a tap root, horizontal roots and vertical branches from horizontal roots. Part of the horizontal roots go into the soil at a well-defined angle in a skew-vertical direction. There are few skeletal roots of the first order in trees of better growth, and in trees that are lagging behind in growth, there are much more of them. At the same time, trees that are lagging behind in growth lack second-order branches and vertical branches from horizontal roots, and taproots are much less developed. This indicates that weaker trees develop the vital soil space with younger horizontal roots of the first order.

In the structure of the root system of the sowing chestnut, the roots of horizontal orientation take the main relative part. However, attention is drawn to the very high relative proportion of roots of vertical orientation in trees of better and medium growth. Thus, the total length of tap roots and vertical branches is 25.7% for trees of the best growth, and 12.7% for the average.

Roots of the second order of branching prevail in the structure of the root system of the sowing chestnut at the age of 10 years. So, for a tree of better growth, the horizontal roots of the first order are 21.7%, the second 46.7, the third 10.9, vertical branches 15.8%, tap root with branches of the first and second orders 4.9% of the total length of skeletal roots.

The core roots of chestnut penetrate to a depth of 3 m. At the same time, the depth of penetration of the core roots of English oak when growing together with chestnut is 4.2 m. exceeds the crown projection area. This situation is characterized by the following indicators: for a tree of the best growth, the crown projection area is 3.14 m 2 , the projection area of ​​the roots is 22. 04 m 2 , i.e. 7 times more; in a tree of medium height, respectively, 1.76 and 12.6 m 2 , i.e. 7.2 times more.

Intensity of population of the soil space by skeletal roots in a tree of the best growth 6.7, medium 6.1, stunted 13.9 m/m 3 .

The horizontal roots of the common chestnut tree are relatively sparse. The diameter of the roots of the first order per 0.5 relative length is 34.9%, which is much higher than that of many tree species. Just like in other breeds, the horizontal roots of the second order in the sowing chestnut are less runaway than the roots of the first order.

How many meters do tree roots drop?

Tree roots are a true masterpiece of nature. From the first moment the seeds germinate, they go in search of much-needed water to keep the plant alive. Water containing minerals needed for growth. But not only that, but also, thanks to the rod, which is the thickest of all, it is well fixed on the floor. Thus, no matter how strong the wind blows, it will be difficult to start it.

Although they also have a disadvantage, and this is that in the incessant search for water, depending on the type, it can damage pipes or any structure. To avoid this, I will tell you how many meters the roots of trees descend .

Index

  • 1 What are tree roots?
  • 2 How many meters do they go down?
  • 3 Deep tap root trees

    This network initially has a distinct primary or main root, which is the so-called rotation that is responsible for anchoring the trees to the ground, but as the trees grow, the roots become mostly shallow, and only a few of them continue to grow vertically. In fact, if we take a mature tree about 50 years old as an example, we can be sure that about 90% of the roots are in the first 50 centimeters of the ground. . But that's not all.

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    And the fact is that the size of the entire root system of a tree tends to match (more or less) the size of its crown, which makes sense if we think that all these branches should receive the water that their roots receive. in most cases from the ground to produce leaves, flowers, fruits and seeds. This means that if we have a tree with a crown about 2 meters in diameter by 3 meters at the highest point, its roots will take up about 2 meters in diameter (in this case, the depth is not taken into account because it is difficult to go down a meter and more).

    How many meters do they descend?

    How deep the roots go depends on several things: soil type , plant species in question and amount of water in the ground . As a rule, the wetter the soil, the longer its root system will be.

    However, You should know that the vast majority of trees, namely 80% of them, as well as the vast majority of their roots, only go down to 60 cm. . From there, they lay out their roots horizontally. The roots of the remaining 20% ​​can penetrate more than 2 m underground, so they will have to be planted away from any buildings.

    Deep tap rooted trees

    Since you are probably wondering what these deep rooted trees are, we couldn't end this article without mentioning the most important ones:

    Genus Ficus

    Image - Wikimedia / Forest and Kim Starr

    Ficus are trees, shrubs or vines native to the intertropical zone of the world. Many species are used as houseplants or garden plants, such as Ficus pumila , Ficus Benjamina o el Ficus robusta . Its height is variable, but can easily exceed 's 10 meters, and its roots extend several meters in all directions.

    Genus Pinus

    Image - Flickr / CARLOS VELAZCO

    Pine (or pine) are woody or shrubby coniferous trees with a crown, usually pyramidal, and sometimes wide and round, which they can reach 30 meters . The best known and most commonly used types are Pinus Pinea , Pinus halepensis or common .

    Genus Eucalyptus

    Eucalyptus (eucalyptus) - trees, especially growing in Australia and New Guinea. It has a fast growth and they can measure over 60 meters. . Its roots are not only unsuitable for growing in a small garden, but also prevent other plants from growing around them. Interesting species for very large plots are, for example, Eucalyptus deglupta for tropical climates or Eucalyptus camaldulensis .

    Non-invasive root trees

    If you are looking for plants with a more shallow and non-invasive root system, I recommend more plants in these genera: from 5 to 15 meters . They are native to tropical and subtropical Asia and there are many species that produce delicious fruits such as Citrus reticulata (mandarin), Citrus x Paradise (grapefruit) or Citrus x sinensis (orange tree).


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