Outlook magazine has some recent articles on ecological restoration and rewilding:
From Seed To Forest: The slow road of ecological restoration
By Ananda Banerjee
India’s Revenant Forests
The country’s programme for restoration of lost green cover makes no sense. Neither on paper nor on the ground.
By T. R. Shankar Raman
Weed out the Brutish Colonisers
By Ramesh Venkataraman
Check the magazine for the link
A critical view on the Miyawaki approach to urban greening/tree planting by Dr RJ Ranjit Daniels and Ms Anjana Vencatesan (Care Earth, Chennai). Worth a read!
Why the Miyawaki Method Is Not a Suitable Way to Afforest Chennai
An article of mine appeared in The Hindu Sunday Magazine today. It stems from work and ideas that Divya Mudappa, I and our team at NCF have been grappling with for many years. Do read. Comments welcome.
This was very well articulated - thanks!
Follow up questoin/debate around 1 few points :
I think a session on some of these, and maybe a platform to share data widely may help. cc @akshay @karanthkk @erbdex @artid @Kapil.097 what say?
Hi,
Thanks for the comments. We are presently engaged in an effort to answer the question regarding the right planting knowledge. It is nascent and I will share details about it if it bears some fruit and at an appropriate time later…
I do not want to take a very hard or purist stance, except for some areas that have high conservation value. There is still large areas, incl. human-use landscapes for a lot of middle ground. The main point is to widen the net of species to more natives as far as possible, rather than more easy/familiar non-natives.
Your third question has to be answered in context of specific areas/landscapes. But this paper might give some ideas of what would be the reasoning or approach:
When is a ‘forest’ a savanna, and whydoes it matter? https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1466-8238.2010.00634.x
See also:
Trees as Nature-Based Solutions: A Global South Perspective
Trees as Nature-Based Solutions: A Global South Perspective - ScienceDirect
Thanks,
~S
This keeps coming up often. Undoubtedly, natural regeneration will create the most robust ecosystems, support most life and are the best way to do it. Of course, there’s the nudges in the amazon one reads about that caused it to be super food rich as well, helping support more life.
But given the populations everywhere, and human needs, what percentage of the total land use can be dedicated to the “truly wild” approach to regeneration? What are the other strategies elsewhere that are still better than “no trees”? How do we create maps of bioregions to help understand and drive this quickly, at scale?
Good points. I think the emphasis on natural regeneration is a case of the pendulum swinging back to counter the hype and hoopla that often accompanies big tree planting projects (the criticism surrounding the Trillion Trees project as an example). And it is true that natural regeneration does work better in many cases but much of the examples the Robin Chazdon and others cite or refer to involve degraded areas that are continuous with larger intact ecosystems (such as near Nyungwe, Kibale etc). When degraded forests/ecosystems abut such larger intact forests/ecosystems, there are opportunities for natural recovery through seed dispersal from adjoining areas etc.
The question about active restoration arises when such degraded areas are in the middle of nowhere or if seed sources or mother plants are simply not there in the landscape anymore. In our own case, we found that rainforest fragments that were more isolated responded better to active restoration, while those near larger tracts of forest less so (and could be left to themselves for more efficient use of resources).
Right now as a part of our restoration efforts, we are also experimenting with different restoration treatment methods (leave it alone, weeding only, seeding only, weeding+seeding etc) to assess what works better or how the recovery differs under different treatments.
Another interesting article from a while ago by Ashish Kothari on the net zero greenwash that is taking root in policy circles:
Climate crisis and biodiversity loss are becoming impossible to ignore
13 July 2021, Ashish Kothari
Dr Chazdon’s plenary at ATREE on Assisted natural regeneration of tropical forests: a cost-effective nature-based solution for conservation & restoration.
A new scientific publication from the Anamalai Hills Rainforest Restoration project under the Western Ghats Programme of the Nature Conservation Foundation (NCF). Free access as of now:
Hariharan, P., & Raman, T. R. S. 2021. Active restoration fosters better recovery of tropical rainforest birds than natural regeneration in degraded forest fragments. Journal of Applied Ecology, Online Early (12 pages). DOI: 10.1111/1365-2664.14052
This appeared in the Economic Times today. Has a number of relevant points flagged for those of us engaged in tree planting programs.
Here’s a screenshot of the e-paper in case its pay-walled.
Also sharing this article that I wrote with Dr MD Madhusudan a little while ago. Appeared in The Hindu Sunday Magazine on 13th February 2022
I learned recently that most of what we think of as “forests” in the Indian peninsula can be categorized more accurately as mesic savannas.
Had a related question from the same - what are the restoration strategies for the same? What would those look like for agroforestry interventions?
Good question. Restoration of mesic savannas (spanning deciduous forests to dry thorn forests in forest type classification) would require focus on both trees and the near-continuous layer of grass cover. Tree densities would be usually at <10 to c. 300-350 per hectare along a moisture gradient, and there would be a good diversity of grasses, herbs, and shrubs to consider. In some ongoing restoration in the Mudumalai-Bandipur landscape, the grasses act to prevent re-invasion by weeds that were removed during restoration.
As for agro-forestry, I do not know very good examples. But some of the coffee plantations in the drier tracts of Kodagu and Hassan have a diverse native tree canopy with other edible fruit trees and crop plants.
The New Yorker has a long read on ecological restoration efforts in India, profiling Pradip Krishen and his work in the arid Roee and deserts of Rajasthan, by Dorothy Wickenden. The article also includes mention of the Ecological Restoration Alliance - India and some of the work of the Nature Conservation Foundation in the tropical rainforests of the Anamalai Hills in the Western Ghats.
by Dorothy Wickenden
My colleagues at the Nature Conservation Foundation have an interesting paper that reviews published work on ecological restoration and outlines how many such studies fall short in describing exactly what they mean by restoration or what kind of interventions (or lack of interventions) was carried out, and what the goals of the restoration were (mainly ecological or economic). They outline the pitfalls in this and suggest ways forward for others in the future to decribe more clearly their goals, approaches, and interventions so that the efficacy of different approaches can be better understood and implemented.
Krishnan, A. and Osuri, A.M. (2022), Beyond the passive–active dichotomy: aligning research with the intervention continuum framework of ecological restoration. Restoration Ecology e13828. https://doi.org/10.1111/rec.13828
Aparna Krishnan also has a neat thread on Mastodon and Twitter on this:
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`Super happy to
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share my new publication with Anand Osuri in Restoration Ecology
@ncfindia
@NCBS_Bangalore
@SERestoration
https://t.co/c6eg0h4Gcw
Aparna Krishnan (@appam) December
3, 2022
An important new publication on montane grasslands and invasive alien wattle plantations in the Western Ghats. The paper indicates that grasslands do a better job in hydrological terms and in reducing runoff and flooding than the invasive alien wattle tree plantations. A highlight from the Abstract…
Our study that replacing grasslands with woody plants at landscape scales, could affect hydrological processes and could increase flood risks during the monsoon, especially in mountainous regions. Management of invaded catchments by regulation of wattle and restoration of semi-natural grassland, combined with the installation of early warning systems in these impacted areas will help reduce flood risk during extreme rain under climate change.
Rajat Ramakant Nayak, Jagdish Krishnaswamy, Srinivas Vaidyanathan, Nick A. Chappell, Ravinder Singh Bhalla,
Invasion of natural grasslands by exotic trees increases flood risks in mountainous landscapes in South India,
Journal of Hydrology, Volume 617, Part A, 2023, 128944. Redirecting
Abstract
Invasive trees in catchments around the world are a source of concern due to their hydrological and ecological impacts. A large number of studies have focused on their impact on dry-season stream discharge due to enhanced transpiration. The impact of invasive trees on stream discharge and flood risk during extreme rain events, which are becoming more frequent due to climate change, has not been addressed adequately. We examined the influence of land-cover, canopy cover, and other catchment morphological characteristics on stream discharges in hilly catchments during light, heavy, and extreme rain events. Three years of rainfall-runoff observations, between January 2014 and December 2016, were collected in eleven neighbouring mountainous catchments in Nilgiris, South India. Each catchment had a distinct land cover, namely shola forests, montane grasslands, and catchments invaded by wattle (Acacia mearnsii). Hourly rain intensities between the percentiles 25–90, 90–95 and over 95 were categorised as light, heavy and extreme respectively, and were used to study hourly peak stream discharge responses. We compared discharge between native grassland catchments and grassland catchments invaded by wattle. Discharge rates were corrected for the catchment area. We found that land cover and canopy-cover influenced the hydrologic response to extreme rain events. Regression models with flood event as the response variable suggested an increase in rainfall-runoff response with an increase in canopy cover. The maximum hourly discharge observed in the reference grassland catchment (0.00098 mm s−1) was lower than the maximum discharge observed in low density (0.00529 mm s−1) and high density (0.00497 mm s−1) wattle catchments. At higher discharges, the flood magnitude in wattle invaded catchments was much greater than that in the grassland catchment for a given flood frequency – indicating a higher risk of severe flooding in wattle-dominated catchments. We attribute the enhanced flood discharges to the effects of spreading wattle roots on the enhancement of rapid, shallow sub-surface flows in invaded catchments. Catchments dominated by shallow sub-surface flows are known to have reduced water retention times in response to high rain intensities. Antecedent moisture conditions and drainage density were other factors that influenced the local rainfall-runoff relationships. In the Western Ghats and other parts of India grasslands have been planted with exotic woody trees, and some have become invasive. Our study indicates that replacing grasslands with woody plants at landscape scales, could affect hydrological processes and could increase flood risks during the monsoon, especially in mountainous regions. Management of invaded catchments by regulation of wattle and restoration of semi-natural grassland, combined with the installation of early warning systems in these impacted areas will help reduce flood risk during extreme rain under climate change.
An interesting article on how bringing the bends back into straightened rivers helped restore the river ecosystem rapidly.
An interesting article and new publication on how fencing can help in passive restoration through natural regeneration of forests in Kashmir.
Passive restoration of Kashmir’s forests has improved soil structure and carbon sink
The full paper can be accessed here:
Passive restoration considerably improved the community structure, soil health and carbon stock in the Pine forests of Kashmir Himalaya, India
Aabid Hussain Mir, Javaid M. Dad, Bikarma Singh, Azra N. Kamili (2022)
Ecological Engineering 176: 106535.
https://doi.org/10.1016/j.ecoleng.2021.106535.
Abstract: Forest restoration significantly enhances soil quality, carbon stock and improves community characteristics, but reports from temperate coniferous ecosystems are limited. The present research aimed to study the changes in vegetation characteristics, biomass, and soil health after eight years of restoration in coniferous forests of Kashmir Himalaya, India. The studied forest stands include the sites before restoration (IN), restored forests (RT) and non-restored (NR) control plots. The results exhibited similar soil texture (clay-loam) in both RT and NR, albeit soils under RT had lower acidity (6.03 ± 0.11) and bulk density (1.21 ± 0.07 Mg m−3) than NR. The average total nitrogen, soil organic carbon, and available phosphorus were 13.2, 32.7 and 19.6%, respectively, greater in RT than NR. For vegetation characteristics, the results exhibited little changes in plant species richness (S = 8 and 7 for RT and NR, respectively), while the stand density and basal area enhancement were recorded for RT. The increase in plant species population and improvement in their regeneration status in RT was observed in comparison to NR in the study area. The density-diameter distribution showed that post-restoration, number of individuals in RT increased substantially in lower (10–25 cm), medium (35–55 cm), and highest (>65 cm) diameter classes with the cumulative percentage increase of 12.2, 44.1 and 12.6, respectively in comparison to the diameter classes 25–35 cm and 55–65 cm which recorded the decrease of 9.8% and 18.3%, respectively. In the case of NR, the results exhibited an alarming trend with a substantial decrease of individuals in lower diameter classes, namely, 15–35 cm (−19.7%), and 55–65 cm (−7.6%), thereby, suggesting the higher vulnerability to degradation than RT. The results of biomass and carbon contents indicated the overall biomass (aboveground and belowground) increase of 97.67 Mg ha−1 in RT and a reduction of 17.46 Mg ha−1 in NR, indicating the restoration added enough biomass to cause measurable changes. The results are evidence of the successful passive restoration efforts via fencing on soil and community characteristics across temperate coniferous forests. Restoring the vulnerable coniferous forests in the Himalayas is recommended to regain their vitality and vigour along with safeguarding the local livelihood options.
Thanks for this. Recently a highway was built through the mountain district of Champawat, Uttarakhand. As part of the roadside plantation they have planted wattles, a big risk to Himalayan ecology. Shall meet the DFO with this and ask him to pull the plug.
