R. Stewart & Tanya Balcar
15.03.07
In response to a number of questions from Planning, Trichy, we begin with some brief answers which are expanded on in the text.
Conflict Between Acacia mearnsii and Flora
The effect of plantation species, especially dense Wattle stands, is the complete extirpation of the grassland ecosystem. The second effect, more positively, is that plantation species, especially Wattle, act as nursing cover for the natural spread of Shola forest species. This spread of Shola is widespread. (See The Palni Plateau, page 5).
On the Poombarai road for example, thirty year old Shola trees can be seen all along the road. March and April are the best time to see this phenomena as the Shola exhibits its bright spring foliage.
Exotics and their Effect on Wildlife
We have never studied wildlife but can make a few observations. Typically grassland birds like the Nilgiri Pipit are completely absent from the afforested plateaus (Bombay Natural History Society ongoing bird study). Gaur have made a comeback everywhere following disease and are now more commonly seen within Kodaikanal itself rather than the forest. VCT has recently conducted a survey throughout the hills for WWF India on animal/human conflict and a report is being prepared. One interesting point of conflict noted was that bison are coming to farmers wells for water as there is none in the forest.
A positive note. We have found Sambar Deer scat at Vattaparai restoration site. This is possibly the closest evidence of Sambar within the vicinity of Kodaikanal since they were reported from Gundattu Shola in 1915 (A.G. Bourne). We refer to Nilgiri Tahr in Wildlife Restoration, page 6. 📷 Gaur at Kukkal grassland (photo by Ian Lockwood)
Water Economy The notes collected here (Appendix 1, Notes on the Water Situation
on the Upper and Lower Palni Hills, A. Jeykumar Albert) are far from a definitive description of the water situation for farming communities in the Palni Hills, but they do indicate that a crisis exists, and the finger is firmly pointed at industrial forest plantations.
That a crisis does exist is acknowledged elsewhere as for the past two years concrete check dams have been constructed all across the Palni and Nilgiri plateaus. We feel these dams are in the main useless, as they are built over impervious granite rock on steep slopes across streamlets that have long dried out. At best they create stagnant ponds that quickly dry out.
Feasibility of Grassland Restoration
There are some who claim that the long life of the Wattle seed bank makes eradication practically impossible in the long term. Our observation of the 12 mile round (page 3) over the years points to a different conclusion; that intervention will alter the trajectory of vegetative succession to something different than if no intervention following cropping is made. How different and the value of that difference can only be assessed in the light of experience. The quantity and quality of difference will in turn depend on the size of any restoration and the amount of inputs applied to it. To simply say Wattle is ineradicable is meaningless. We have seen much eradicated and eradication should underline our methodology even if the literal meaning of total eradication is not attainable.
The term restoration is also problematic if we apply it literally to mean the turning of the clock back prior to disturbance. This indeed would be practically impossible in such a complex matrix that is the Shola/grasslands. The question really should be can we help bring into being a functional self-sustaining/evolving eco-system that is biologically diverse and for those who require a utilitarian motivation can restore eco-system services here exemplified by water. Whatever one’s persuasion the theoretical paradigms of the emerging tendency with Restoration Ecology (Restoring Natural Capital, RNC See Appendix 2 Restoration of Natural Capital, Clewell, A.F. 2000 and Nature Conservation as if People Mattered, Aronson et al. 2006) can guide us. While RNC addresses the practicalities of nature conservation in massively altered or destroyed ecosystems along with human needs, the traditional principles and guidelines of Restoration Ecology can still provide a basis for guidance. See
Appendix 3. Restoration principles and guidelines, Divya Mudappa & T.R. Shanker Raman, excerpt from NCF & VCT(2006) Principles for rainforest and grassland restoration in the Annamalai Hills. Nature Conservation Foundation & Vattakanal Conservation Trust.
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Eradicating Wattle etc.
The first priority here is identifying those areas of grassland which are still relatively healthy but are experiencing ongoing colonization by Acacia mearnsii. The Kukkal grasslands are free of invasion but other areas of grassland toward the Kerala border such as Vanderavu and Ibex Peak are vulnerable. We have not visited these remote areas since 1998. Extent, intensity and time period over which invasion has occurred would determine the nature of any intervention. GIS mapping and ground proofing would be necessary. Another important grassland, Agamalai under Theni Forest Division we have never visited, but invasives are reportedly present.
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Acacia mearnsii
as a native in Australia
There are 11,824 hectares under Acacia mearnsii plantation in the Palnis (photo by Damian Magner)
A widespread and deeply entrenched view is that Acacia mearnsii suckers from the roots. This is not true but stumps, especially of young trees, coppice profusely. We have established a four stage guideline for the eradication of individual plants.
1. Seedling stage 0-2 years to be uprooted.
Green bark stage 2-5 years to be cut hard at the base.
Grey bark stage >5 years to be cut and the bark stripped off.
Black bark stage – old trees to be cut at a convenient height. Usually no regrowth. Should sprouts emerge they are easily destroyed.
Seed Bank
This and not regrowth from stems is probably the biggest challenge to the eradication of A. mearnsii. It has very high seed production, with a seed bank of up to 20,000 per m developing under a mature canopy. Fire stimulates germination whereafter it forms dense thickets. (Plant Invaders. Cronk, Q.C.B. & Fuller, J.L. 1995.). This can currently be seen in Mukurti National Park following fire in 2004.
Our hope (see Twelve mile round observation below) is that this seed bank can be effectively smothered by native vegetation with reweeding, and recropping on a regular basis. South Africa has experience of tackling Acacia mearnsii over several decades and in much larger areas than here. We were not able to find any detailed studies or descriptions of their eradication on the internet, but it would be advised to track this down or seek the advice of their Forest Department.
Another Side to Wattle
In February 2005 we noticed that a large number of Acacia trees were showing signs of stress or death. Post monsoon 2006 and 2007 this process has intensified with tens of thousands of trees now on the brink of death.
Last year Acacia mearnsii did not flower: we believe the trees shut down due to lack of water. However they did begin to flower towards the end of the North East monsoon in 2006. Now, having committed themselves to fruiting they are again faced with water stress. We wonder, given this commitment whether they will be able to shut down or will they throw their last resources into seed production before dying. Some foresters put the dying down to old age and the lack of coupe rotation in recent years, but the dying is occurring everywhere and among trees that never were part of any cropping rotation, and among trees that are clearly submature.
Acacia mearnsii is an understorey tree of Eucalyptus under fairly arid conditions. In its native Australia it does not grow to a great size. We believe that here it has thrived, not only in the monsoon season, but has drawn on deep water supplies which are now exhausted. The water gone, being overgrown and bloated, the tree cannot sustain itself.
Interestingly (12 Mile Round) you can see Wattle growing as an understorey to Eucalyptus. Its growth is spindly but they are not dying.
If we are correct in surmising that those Wattle coupes, recently felled, benefited from the now exhausted ground water, the regrowth now under way should be weaker but better adapted, like their native Shola counterparts that have evolved to deal with the long dry and wet seasons. Young Shola saplings can be seen to be thriving among stressed Wattle.
Twelve Mile Round and Coupe Fellings
Kodaikanals Twelve mile round has been subject to a programme of roadside Wattle clearing and the planting of Shola species for about 6 years. it is a very conveniently located route for observing the processes that occur following the first cut of timber quality trees. We have not observed any repeat cutting to date and it is possible to see various post-cutting scenarios from different years although unfortunately these were not meticulously dated by us.
Observations
1. The vast majority of stumps have not coppiced.
2. The strength of re-emergence of plants from the seed bank is uneven and sometimes weak.
3. In some areas where the germination of seedlings is weak, carpet forming grasses have become well established, especially the native grass Digitaria wallichiana.
4. Rubus species i.e. thorny raspberry have an unnaturally high population in the regeneration plots following felling. Rubus, normally a plant of the wayside and Shola border is assisted by plantations to spread and eventually dominate broad swathes of land. In the Palnis Rubus ellipticus is the most common while in the Nilgiris, most notably in Mukurti National Park, its place is taken by Rubus fairholmianus.
5. Shola plantings have struggled to overcome repeated grazing and drought.
6. Clearing of Wattle has exposed a number of young Shola saplings (5-20) years that had established under its cover. These, especially Daphniphyllum neilgherrense , continue to thrive.
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Apart from initial felling, and the planting of Shola saplings these processes have unfolded without any further deliberate intervention. It is not too late to make a positive impact. Native grasses can be introduced. Rubus can be used to protect Shola seedlings. Rubus itself while now dominating much of the 12 mile round can elsewhere be eradicated in its early stages of development by uprooting the seedlings. Because of the sub-surface creeping spread of older plants their cut stumps need to be painted with a solution of Glysophate, the safest and most commonly used weedicide in agriculture and eco-restoration.
Much of the seed bank regeneration of Wattle has now grown to fuel wood size and has begun to set flower. Re-cropping now would prevent further additions to the seed bank.
Ideally the processes described above, both positive and negative, should be attended to soon after, during or even before the initial felling of the coupe.
Any project area be it marsh restoration, coupe or the 12 mile round would require a long term management plan focused on suppression of the Wattle seed bank and species enrichment. Engagement of NGO’s like VCT and voluntary labour has huge potential in these processes. Internationally the Society for Ecological Restoration is keen on helping and is developing a strategy for South Asia. Lastly the dozens of women who headload firewood into Kodaikanal and elsewhere can be directed to restoration sites. Regarding voluntary contributions VCT has been able to assist the Forest ranger and foresters at Vattaparai, a wetland restoration, by mobilising volunteers on a regular basis. We have managed to destroy tens of thousands of Wattle seedlings.
Pennisetum clandestinum – Kikuyu grass
This mat forming grass introduced from East Africa has proven to be a good soil binder, especially in semi-urbanised Kodaikanal. Under heavy grazing and trampling pressure it forms a thick carpet which forces out other species creating a lawn like monoculture. Achieving a balance between this all pervasive and tenacious grass and other species could be the greatest challenge in any grassland restoration; this is especially so in that any grassland restoration will attract both cattle and Bison.
Materials for Restoration
Grassland nurseries should be established at headquarters like Berijam and the disused Konalar settlement focused on multiplying common grasses that provide the basic structure of grassland. Detailed strategies for revegetation should evolve through experimentation and trial and error.
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Shola Restoration
Shola saplings should only be raised for assisting the regeneration of existing degraded Sholas, most of which have been fenced for years but never treated restoratively, and are usually unable to regenerate because of weed thickets, Shola saplings can also be raised as ornamentals for road side plantings etc.
See Appendix 4, Restoration of shola/grassland ecosystems – insights from the Palni Hills, R. Stewart & T. Balcar, excerpt from NCF & VCT(2006) Principles for rainforest and grassland restoration in the Annamalai Hills. Nature Conservation Foundation & Vattakanal Conservation Trust.
Degraded Bombay Shola
The Palni Plateau
Most of the Palni plateau grasslands have been under forest plantations for several decades. Much of this is rapidly diversifying, with native Shola trees increasingly making their presence felt. The older a plantation and the closer to an existing Shola the greater is the conversion. Management, if any is required of these extensive areas should be light handed. We have watched this process evolve for over 20 years and we are convinced of the superiority of better adapted, longer lived, native Shola species in this rapidly evolving picture.
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People seeing a 30 year old Shola tree for the first time, surrounded by Wattle, will tend to see it as being under siege when in fact it is a deep penetrator of the latter. In some instances (above Blackburn marsh) we have witnessed the almost complete conversion of Wattle plantation to young Shola. This process of plantation to Shola can also be seen very vividly on the road approaching Kukkal. Another remote location, visited by us in 1998, was Marion Shola. We were then struck by the density and sterility of the extensive Wattle plantation in the vicinity of the rest house. We returned after eight years in 2006 and found thousands of Shola trees on the march. Interestingly the larger saplings we could assess as being about 8 years of age demonstrating that the sterility of 1998 was only illusory. While Acacia species may be the best nurse for Shola, Eucalyptus and even dense Pine plantations will eventually give way to Shola.
Chrysoglossum maculatum
growing on a Wattle stump
Given these very positive processes practise is potentially freed up to examine the plateau landscape in more detail. For example on rock sheets in shallow soil grassland species have managed to survive. Between these rock sheet islands plantation species struggle to survive. Cleaning up these spaces could create fairly large grassland reserves within the newly forested landscape. Likewise with some peaks, most notably Perumalmalai (and Vandaravu?) good grassland survives beneath struggling Eucalyptus.
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Re-engagement with the 12 mile round could provide the basis of an ever widening strip of “restored” grassland or “Shola savannah”. This would include for example the ongoing restoration of the marsh at Vattaparai which would also benefit from further FD engagement. Preventing the loss of pristine grassland would however remain the first priority. Also the grasslands at Mannavanur should be monitored to ensure the Acacia mearnsii on its borders are kept in check.
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Larger Restoration Projects
Berijam Lake
Berijam Lake at 2000m is a large ancient man made lake with a catchment area of 70sq.km. and delivers water to the plains town of Periakulum in Theni district.
Dried up - 2003, photo by Ian Lockwood
A number of large Sholas discharge water into the lake via marshes at the headquarters end, but most of the catchment area that was formerly grassland underwent afforestation during the 1960’s, with Eucalytus, Pine and Wattle.
Knowing the lake since 1985, it was not until August 2005 that it occurred to us that the lake was some way into a crisis. We could see that the main Berijam marsh was shrinking and had been for some time. Today (March 2007) it is possible to walk across the marsh without getting your feet wet.
Simultaneously the creek waters adjoining the marsh are being consumed by new marshland vegetation. The lake appears to be shrinking. The speed of this process can be symbolised by the fact that this year the boating dock has been forced to move to deeper waters on the opposite side of the creek. It looks like this landing site will also only be temporary as vegetation advances. The spread of aquatic vegetation has been augmented by the recent introduction of the Water Lily, Nymphaea nouchali, which also covers the surface of the shallows of Kodaikanal lake. The species associated with the primary advance of vegetation is the native Panicum repens, its common English name, Torpedo grass, aptly describes its growth habit as it sends its shoots out into the water which root at the nodes eventually paving the way for typically marshland sedges to establish themselves. All around the banks of the lake this same process can be seen on a lesser scale. The filling in process is facilitated by the debris of fallen trees and siltation from unstable plantation soils.
An obvious response to this siltation will be to eventually raise the height of the dam. This has been the response to the silting up of Kukkal Lake after grassland was converted to potato production. The problem with this strategy at Berijam is that it does not address the drying out of the catchment area, i.e. that less water is arriving to be dammed, as is exemplified by the visibly drying marshes.
A feature of much of the afforested catchment area of the lake is the relative absence of advancing Shola especially westwards towards Mannanavanur. Restoration to grasslands in these “sterile’ plantations could only be positive ecologically, biologically, as well as perhaps being the only long term solution to maintaining Berijam lake as a viable source of water for Theni district.
📷 Nilgiri Tahr on the Southern slope (photo by Ian Lockwood)
Wildlife restoration – The Southern Crest of the Palni Escarpment
The grassy slopes adjoining the precipitous cliffs of the Palnis Southern edge were once grazing grounds of the endangered Nilgiri Tahr. These slopes are now dominated by plantation species and other rank vegetation such as Eupatorium (Ageratina adenophora). The Tahr grazing is now restricted to the cliff face which previously served primarily as a source of refuge.
The plantations at the crest are frequently ravaged by wild fire and dead tree stems with weeds constitute one of the most sterile and unproductive habitats anyone could imagine.
Occasionally a rocky outcrop provides some respite. One of these, Pass Peak opposite Marion Shola rest house, we used as a vantage point during the monsoon of 2006. It was clear from the droppings around us, we had occupied a favourite resting spot for Tahr. The peak represents the perfect starting point for a restoration of the entire Southern crest, with for example an initial target of 50m. width. The doability of this restoration is underlined by a number of factors.
The proximity of an existing parallel road.
The proximity of rest houses and the disused FD headquarters at Konalar with ample water for raising restoration grasses.
The crest already has an existing though largely unmaintained fire break that can be developed with grasses.
The crest is potentially one of the World’s most spectacular short distance trekking routes raising the possibility of high value eco-tourism and voluntary contributions to the eco-maintenance of the route.
The regrassing of the crest would facilitate the survival of the Tahr population, attracting funds from those concerned with large mammal conservation as well as those concerned with landscape restoration and endangered flora.
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A First Priority for Restoration. The grassland towards Vandaravu (photo by Ian Lockwood)
Summary of Recommendations
Reduced budget for Shola plantings. Increased budget for ecological restoration. Shola saplings to be for restoration of degraded Sholas only or as ornamentals. Maximum investment in nursery years and aftercare of saplings. Establishment of grassland nurseries focused on producing c.12 main grass species. Grassland materials to be produced in reusable containers. Restoration work to accompany coupe felling. Re-engagement of the FD on the 12 Mile round. Re – cut the newly flowering Wattle on the 12 Mile Round before they set seed. Re-engagement of the FD at the Vattaparai marshland. FD to forge a relationship with the Society for Ecological Restoration International and Restoring Natural Capital. FD to empower the firewood women in the direction of ecological restoration. FD to encourage voluntary community involvement with the help of VCT. VCT to identify and map the status of the surviving grasslands using GIS methods. First priority is to secure these grassland fragments. Keep an eye on Mannavanur grasslands. Clean peaks with surviving grassland eg. Perumalmalai. Expand sheet rock grassland reserves In 2000 VCT with the Research wing of the FD completed a proposal for making a grassland reserve in Vattakanal alongside Vattakanal Shola. Can this be resurrected ? Identify water bodies for catchment restoration. No more check dams No more new fences. There should be a permanent fence maintenance crew, especially for Sholas. Save Berijam Lake. Augment the Tahr habitat through ecological restoration. Reopen Konalar. Direct scientists of all disciplines, including social scientists, to look into why the Wattle is dying, hydrology, the spread of Shola, investigate the economics of the hill village communities etc. Seek the advice and help of the South African FD. Leave old evolving plantation stands to go their own way. This involves large areas.
VCTrust
21/45 A&B, Pambarpuram
PO Box 109, Kodaikanal
Tamil Nadu
Tel. 04542 243190, 9842143190
robertstewart@vattakanalconservationtrust.org tanya.balcar@gmail.com
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