Udanti-Sitanadi: Bridge Grafts Weighed for 500-Plus Girdled Trees

A forest landscape, not an isolated group of garden trees

The reserve lies in Chhattisgarh's Gariaband and Dhamtari districts. The National Tiger Conservation Authority records a total area of 1,842.54 square kilometres, including an 851.09-square-kilometre core and a 991.45-square-kilometre buffer. Udanti and Sitanadi are its two core areas, named after their rivers. These waterways provide permanent water sources for wildlife. The reserve's importance thus extends beyond individual trees: vegetation, water availability and connected habitat support the wider landscape.

The Udanti forests adjoin Odisha's Khariar forest division and the Sonabeda sanctuary landscape. Official assessments also identify connections towards Kanker, North Kondagaon and Indravati in the Bastar region. These are ecological connections, not a claim that all these forests belong to one legally notified reserve. Damage within one part can weaken a larger habitat network. Protecting surviving trees and preventing further clearance are therefore complementary tasks, even when treatment focuses on individual trunks.

The trunk contains several different working tissues

A woody trunk is not simply a solid pipe wrapped in disposable bark. Xylem, the wood-forming transport tissue, carries water and dissolved minerals. Phloem, towards the outside of the vascular system, carries sugars and other products of photosynthesis. Between them lies the vascular cambium, a thin layer of dividing cells. It produces new xylem towards the inside and new phloem towards the outside, helping the trunk increase in thickness.

Removing or seriously injuring a continuous ring of bark can sever the phloem and damage this growth layer. The leaves may still manufacture sugars, but their transport to tissues below the wound is interrupted. Roots need those energy-rich products even though they absorb water and minerals from the soil. A tree can therefore become physiologically disconnected without being cut down. Saying that girdling merely removes a protective outer covering misses the injury to its living transport system.

Why green leaves do not necessarily mean that the tree is safe

The University of Florida explains an important distinction: after bark and phloem are removed, water can initially continue through remaining xylem. It is therefore misleading to describe every girdling injury as instantly stopping all upward water movement. In fact, controlled girdling is sometimes used in plant propagation because it changes the movement of growth-related substances. What happens next depends on the tissues affected and whether a living connection remains or develops across the injury.

This explains the apparent contradiction in the reserve: a standing, leafy tree may still face a serious threat. Visible crown condition alone cannot establish that roots are receiving enough sugars or that the transport break has healed. Nor does every bark scrape amount to complete girdling. The circumference affected and the survival of living tissue matter. An assessment must distinguish a superficial injury, a partial interruption and a continuous break around the trunk rather than treating them as equivalent.

A bridge graft aims to reconnect, not simply cover, the wound

Bridge grafting uses a short piece of suitable stem, called a scion, to connect healthy tissue below and above the injury. The University of Connecticut describes the aim as restoring carbohydrate movement from the leaves towards the roots. The scion must be compatible with the tree. Its living layers must make effective contact with the corresponding tissue on both sides of the gap. A branch placed against exposed wood does not automatically become a functioning bridge.

This is also different from replacing the tree's entire root system. A related technique, inarching, uses a rooted shoot or young plant to establish an additional connection. Connecticut's guidance distinguishes that approach from an ordinary bridge made with detached scion wood. The appropriate repair depends on where the injury extends and which tissues remain viable. These are specialist horticultural judgements, not interchangeable names for wrapping damaged bark.

Timing and species determine whether the idea can work

University of Florida guidance recommends bridge grafting when bark separates readily during active seasonal growth, using dormant young stem material. West Virginia University's account likewise stresses collecting suitable scions and preventing them from drying or beginning growth before use. Those recommendations come largely from temperate orchard practice. They explain the biological requirements, but their calendar cannot simply be copied onto different forest species in Chhattisgarh. Local growth cycles and the condition of each tree need assessment.

The reported conservation plan is therefore best understood as a trial of carefully selected repairs, followed by care and monitoring. The Indian Express records officials' acknowledgement of limited success in an earlier local effort and their decision to seek expertise. That account does not supply a predicted success rate for the new intervention. Fresh damage may leave more opportunities than long-standing injury, but it does not guarantee recovery. Preventing additional damage remains essential while rescue options are assessed.

Girdling can also happen without deliberate bark removal

The same transport problem can develop when a root grows around the trunk and compresses it. The University of Maryland Extension calls these stem-girdling roots and links them to restricted carbohydrate movement towards the root system. Such roots can arise in container-grown plants and develop after planting. Poor planting depth, compacted soil and excessive mulch can contribute to the problem. This is gradual constriction, rather than necessarily a freshly cut strip of missing bark.

Maryland's guidance emphasises prevention, early detection and professional assessment of large roots. Removing a substantial root can itself affect the tree, so the diagnosis should come before an attempted remedy. Intentional ring-barking, animal feeding and constricting roots can produce related physiological damage through different physical processes. This wider use of the word matters when reading reports. The reserve's reported injuries concern alleged deliberate girdling; evidence from urban root problems explains the mechanism, not who caused those particular wounds.

A management tool does not justify unauthorised forest damage

Girdling is sometimes used in planned habitat management to create snags, or standing dead trees. The United States National Park Service describes their value for cavity-nesting birds and mammals. Selective thinning can also admit light to established seedlings beneath a dense canopy. But its guidance stresses treating invasive plants and ensuring desired regeneration before making canopy openings. Otherwise, opening the canopy can favour unwanted vegetation rather than the intended forest community.

Dead wood therefore has ecological value, but that does not make every act that kills a tree beneficial. Massachusetts wildlife guidance warns that standing dead trees must be considered in relation to trails, people and fire-management risks. Selection, location, safety and a defined habitat objective are central to an authorised management decision. They are fundamentally different from the alleged use of girdling to facilitate encroachment. The physical technique alone cannot establish either a conservation purpose or legal permission.

Conclusion

The Udanti–Sitanadi rescue proposal shows why forest protection requires attention to living processes, not just a count of standing trunks. Girdling threatens the connection between leaves, roots and growing tissues; bridge grafting attempts to rebuild that connection. Its success must be demonstrated through survival and continued growth, not inferred from a dressing or a green crown. Specialist assessment, suitable timing, follow-up care and prevention of further damage must work together. The aim is to protect the forest, not merely treat its visible wounds.