Posts Tagged ‘ecological restoration’
Preliminary Analysis of Land Cover in the Sinharaja Adiviya using Planet Dove Imagery
Figure 1: Sinharaja Adiviya (or greater Sinharaja area) mapped with Planet Dove imagery. Reduced in size to fit this post.
In March this year I attended a fascinating talk entitled “Sinharaja: From a Timber Reserve to a Biological Treasure Trove. What next?” by Nimal and Savitri Gunatillike at the BMICH in Colombo. The lecture was sponsored by the WNPS in their monthly lecture series. There were several aspects of the talk reflecting back on their decades of research in Sri Lanka’s preeminent forest. Initially, Savitri did botanical studies documenting the diversity of plants in Sinharaja in the period before mechanical logging started (1960s-77). They were witness to period of commercial logging and recovery to a world renowned UNESCO-designated world heritage site. The Gunatilleke’s experiments with rainforest restoration were of particular interest to me, given the lessons that these examples hold for similar non-native plantation areas across the Western Ghats/Sri Lankan biodiversity hotspot. In the lecture, both spoke of the broader Sinharaja area of forest fragments and large patches that are connected or satellites to the core area-something they identified as the Sinharaja Adiviya.
At the same time, I was interested in mapping land cover and forest types in study areas that I take students to for field work. Up to this stage, our DP Geography studies in Sinharaja have utilized Survey Department 1:50,000 and 1:10,000 land use data. It comes as a shape file with the data that I have purchased from their map sales office. This data is satisfactory but we have found significant omissions and inaccuracies in the Kudawa area where OSC students conduct field work (much of the data is based on surveys conducted in the early 1980s).
Forest types and land cover are a key part of the Sinharaja story. Literature about the area’s successful conservation refer to primary and secondary forest as well as Pinus caribaea plantations (along the border). Yet, I couldn’t locate GIS-ready shapefiles of boundaries of these forest types! The Forest Department has files based on its 2010 forest cover map but these are, thus far, not in the public sphere. I had mapped the area using a Landsat tile from 2005 (published in my blog in 2012) but this was before I had learnt how to conduct a supervised classification of a raster image.
Home garden landscape on the border with Sinharaja rainforest (north west side). (September 2019)
Pinus caribaea plantation in the Sinharaja buffer zone undergoing ecological succession as part of an ecological restoration effort. This area was once dominated by a monoculture community. The intervention of conservationists in thinning pine trees and planting appropriate native species is helping to return it to the climax lowland rainforest community. See linked articles by Professors Mark Ashton, Nimal Gunatillike and others for details of these efforts. (September 2019)
Primary/ridge forest below Moulawella Peak in the Sinharaja core zone. This area did not experience any logging in the period of commercial exploitation in the 1960s-70s. (September 2019)
A Brief Literature Review
A review of land cover analysis in Sinharaja shows that only a few studies have been published to date. The most significant, publicly available study looking at land cover change in Sinharaja was conducted by Buddhika Madurapperuma and Janak Kuruppuarchchi in 2014 (see link). Their analysis used Landsat ETM data between 1993 and 2005 in an area slightly larger than the Sinharaja boundary provided by the Forest Department. They used a Normalized Difference Vegetation Index (NDVI) and Burn Index (BI) to assess changes in three years (2001, 1993 and 2005). The study is thorough but the data that they use is coarse and it is difficult to get a sense of the land cover patterns at a large scale. They conclude with an acknowledgment that ground surveys need to be conducted to better understand the change. Thanura Madusanka Silva published a study entitled “Land Cover Changes of a Tropical Forest Buffer Zone” in 2018 that used Sri Lanka Survey Department data to assess changes in land use in the Kudawa area (see link). This study is based on secondary data and not satellite imagery and it concludes that major change has occurred in home garden areas. There may be other studies that I have missed but the field of land cover change in Sinharaja, as seen in satellite imagery, is ripe for further study.
Figure 2: Supervised classification of land cover based on Planet Dove imagery. Because the images were not collected on the same flight, there are some unavoidable gaps and seams, that are visible on close inspection.
Planet Dove Methodology and Results
Two years ago I became familiar with Planet Dove imagery and saw that it might provide a solution in my attempts to classify land cover in the Sinharaja area. Planet Dove’s constellation of 120+ satellites, which revisit the same areas every day, offers a new opportunity to visualize and analyze any area of the earth. At the beginning of 2019 I successfully applied to Planet’s Education and Research program and was able to download a host of tiles of study areas. I found a series of cloud-free scenes from December 2018 and downloaded them. These are from around December 18 but some were collected at slightly different dates. Using ArcGIS, I mosaiced these various tiles so that I had most of the area Sinharaja Adiviya covered. Because the images were not collected on the same flight there is some unavoidable gaps and visible seams, that are visible on close inspection. The improved spatial resolution of 3-5m means that it is easier to distinguish between different land cover types (lowland rainforest, vs, Pinus caribaea plantation, for example). Initially I worked on a map using the non-visible near infrared (NIR 780-860 nm) layer to highlight vegetation (see figure 1).
In the second part of my efforts I conducted a supervised classification using tools in ArcGIS’s Spatial Analyst extension toolbar. For land cover type, I collected between 5 and 10 training samples and merged each of them into their own distinct land cover type. The classified image (Figure 2) clearly highlights the dense lowland rainforest pockets in a landscape dominated by home garden and tea agriculture. The effort to categorize the Pinus caribaea plantation was partially successful. However, there are errors with some of the classification. For example, plantation in the midst of dense (primary) forest near Moulawella peak.
Conclusion/Future
In the next attempt I plan to collect more training samples in the hopes of getting a more accurate picture of the land cover patterns. A focused study on the pine forest in the buffer area near Kudawa deserves attention. Some of these areas are being successfully restored to their original lowland rainforest vegetation type and time a change study would be illuminating. There are areas of the landscape that I am very familiar with (the Kudawa tourist and village zone) while I have far less personal experience in other areas like western Sinharaja and the various forest fragments. Further studies of landcover need to be verified with ground truthing in the field.
Figure 3: The Kudawa area of Sinharaja with classification of land cover based on Planet Dove imagery. In this image I have highlighted the popular tourist area around the settlement of Kudawa. The lower part of the map experienced mechanical logging 40+ years ago (some of it is encircled in red). The stream running down to the Sinharaja ticket gate is not depicted on this map and is missing from Survey Department 1:10,000 sheets that were used for the hydro/stream layer.
SELECTED REFERENCES (Land Cover Focus)
Ashton, Mark et al. “Restoration pathways for rain forest in southwest Sri Lanka: A review of concepts and models.” Forest Ecology and Management 154(3):409-430. December 2001. Web.
Ashton, Mark et al. “Restoration of rain forest beneath pine plantations: A relay floristic model with special application to tropical South Asia.” Forest Ecology and Management 329:351–359. October 2014. Web.
Gunatilleke, Nimal, C.V.S. Gunatilleke and M.A.A. Dilhan. “Plant Biogeography and Conservation of the South Western Hill Forests of Sri Lanka.” The Raffles Bulletin of Zoology, 2005. No. 12 9-22. Web.
Gunatilleke, C.V.S, et al. Ecology of Sinharaja Rain Forest and the Forest Dynamics Plot in Sri Lanka’s Natural World Heritage Site. Colombo: WHT Publications, 2004. Print.
Lockwood, Ian. “Into the Wet: Field Notes From Sri Lanka’s Wet Zone.” Sanctuary Asia. August/September 2007. 3-11. Print. PDF.
Madurapperuma Buddhika and Kuruppuarachchi Janaka.“Detecting Land-cover Change using Mappable Vegetation Related Indices: A Case Study from the Sinharaja Man and the Biosphere Reserve.” Journal of Tropical Forestry and Environment Vol.4, No 01 (2014) 50-58. May 2014. Web.
Madusanka, Thanura. “Land Cover Changes of Tropical Forest Buffer zone A case study of Kudawa Village, Sinharaja forest buffer zone; Sri Lanka.” International Journal of Scientific and Research Publications. October 2018. Web.
Ministry of Mahaweli Development and Environment. Proceedings of the Stakeholder Workshop on Landscape Planning & Management. 29 September 2017. Web. See page 10 for Sinharaja map.
Planet Team. Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. 2017. Web.
Sri Lanka Survey Department. District Land Use Maps. 1983. Print/Web.
UN-REDD Programme. Sri Lanka’s Forest Reference Level submission to the UNFCCC. January 2017. Web.
Wijesooriya W. A. D. A. and, C. V. S. Gunatilleke. “Buffer Zone of the Sinharaja Biosphere Reserve in Sri Lanka and Its Management Strategies.” Journal of the National Science Foundation of Sri Lanka. 31(1–2), 57. June 2003. Web.
Recent Publications
Opening image in Frontline article. The image shows winter mist in eucalyptus plantations below Perumal Peak with remnant montane grasslands.
In the last several months I have had the opportunity to have two important portfolios of black & white images published in prominent Indian publications. In September the Indian Quarterly published a photo essay on sholas in the Western Ghats entitled “Spirit Mountains.” This collection of images and a short text grew out of an online conversation with Suprarba Seshan who was looking for images to accompany her article “People of the Rain” article that appears the same issue. Her article went on to be illustrated Diba Siddiq who is also associated with the Gurukula Botanical Sanctuary, while I was allotted ten pages for the shola story. The issue is focused on rain and also includes a story about Agumbe by our prolific writer friend Janaki Lenin. Avtar Singh, the managing editor based in New Delhi, played a key role in pulling it all together. The images, all black & white, were chosen to illustrate the aesthetic themes of rain and diversity as seen in the sholas of the southern Western Ghats.
Some of the pages from the Indian Quarterly photo essay “Spirit Mountains.” Published in July 2015.
This month Frontline has just published “Plantation Paradox” a photo essay accompanying my rambling exploration of the complications of non-native timber plantations in the Palani Hills. The Chennai-based magazine is part of the larger Hindu publications group-known for their reasoned, somewhat left-leaning reporting and support of secular, multicultural India. The pictures in this story are also all black & white and closely illustrate themes from the 3000+ word article. The article includes a version of the GIS-generated map (utilizing 30m SRTM USGS/NASA tiles) that I worked on earlier this year. It illustrates the 1,500m contour (shola/grassland areas) in the southern Western Ghats. Vijayasankar Ramachandran, the editor at Frontline was my contact who made this publication possible. We have worked together on several past articles that explored themes of conservation and ecology in the Western Ghats and Sri Lanka. In particular several of my Frontline articles have focused on issues in Kodaikanal and the Palani Hills where changes in the ecology, pressure from tourism and ambiguity about the status of the conservation of remote hills has been in flux (see list & links below).
PALANI HILLS ECOLOGY/CONSERVATION ARTICLES IN FRONTLINE*
- 2012 April “Breathing Life Back into the Sholas”
- 2009 November “Fragile Heritage: Bombay Shola”
- 2006 August “Kurinji Crown”
- 2003 August “The Palni Hills: On the Danger List”
* There used to be web links for these but my understanding is that they are not active anymore.
Note: My spelling of Palani has evolved over time as seen in the title above. I previously used to use “Palni” (as in what is used by the PHCC). However, after talking with Tamil language experts and looking at changes in official documentation, I have adopted the widely accepted “Palani.” This is how the temple town, that the hills are named for, is spelt. For Kodaikanal, I continue to use “Kodai” while I have noted attempts by some individuals and publications to shorten this to “Kodi!”
Ecological Restoration in the Palani Hills
Breathing life back into the sholas…spreads from the Frontline (20 April 2012) article.
Last summer while enjoying a holiday in Kodaikanal filled with hiking and outings with friends at the Vattakanal Conservation Trust it occurred to me that it was time to update the status of the ecology in the upper Palani Hills. Some of the observations were published in earlier blog posts but Bob, Tanya and I were also looking to reach a broader audience. Frontline, with the able support of Vijaykumar has now published a series of my articles on the Palanis (2003), the Kurinji flowering (2006) and Bombay Shola (2010) all geared at raising awareness through text, photographs and maps. It was thus logical to look to them to highlight the current status of the upper hills. We took several fact-finding expeditions during June and July into the hills and the state of remnant montane grasslands was quite alarming. The spread of non-native species into these last outposts was significant.
It took me a while to get the article and pictures together for Frontline but earlier this month it was published as Breathing Life Back into the Sholas(click here for the HTML version). Bob & Tanya, meanwhile worked with various authorities to get permission and raise funds to do some emergency restoration work in the habitats that we had visited. Their field notes had alerted people to the issues that I have highlighted in the article. On our family’s recent visit to Kodai I was thrilled to hear that VCT has the go head and will shortly be organizing a team to spend time doing restoration work in those highly sensitive cliff areas. Above and below are the spreads from the article. In spite of the title, the article is really about recognizing and restoring remnant montane grasslands habitats (sholas, you will read, are actually doing quite well in the Palani Hills).
Breathing life back into the sholas…more spreads from the Frontline (20 April 2012) article.
One of the key recommendations of several conservationists, as well as the article, is that there is an urgent need for an updated and dynamic GIS of the Palani Hills. This may well be in the process with the support of various agencies and NGOs. In the meantime I’m working on a map for VCT highlighting the 1,500m contour (where shola/grasslands start in most areas). This is still a work in progress…
Restoration & Revival in the Anamalais
We had a very satisfying encounter with a troop of Lion Tailed Macaques (Macaca silenus) that was in the process of raiding the Puthuthottam Estate hospital. I was able to follow them into a patch of mixed plantation and natural vegetation forest to take the pictures in this post.
(PART II IN A SERIES OF THREE)
The South West was in full force when Lenny and I drove to the Anamalais from Kodai via Palani and Udumalpet. We had hired the good services of AP John and his small Indica for the three-day rip. The Anamalais Tiger Reserve (ATR) is a large and expansive protected area though it is interrupted by large patches of human settlements and modified landscapes. Most people looking for wildlife will head to Topslip, which is south-west of Pollachi. The Valparai area has traditionally attracted fewer people and for good reason. The accommodation options are limited and the area is dominated by large monoculture estates of tea. Access into the forests and high Grasshills area of ATR is strictly restricted and is not a viable option without significant bureaucratic gymnastics in Chennai and Pollachi.
- Clearing showers over the Aliyar reservoir looking east into the Anaimalai Hillss.
The ride up to Valparai is worth the trip in itself. The ghat road up from Udumalpet via the Aliyar reservoir has an incredible 40 hairpin bends (the Battlagundu-Kodaikanal ghat only has one for comparison’s sake)! The road winds its way up a steep ascent with dry deciduous and thorn forest that quickly changes into moist-deciduous and then evergreen rainforest in the space of 10-20 kilometers.
View looking north from hairpin Bend #9/40 on the Pollachi-Valparai road. At times this is a good location to see Nilgiri tahr.
One of the most promising conservation projects in the Western Ghats is based out of Valparai where the Nature Conservation Foundation is working with several tea estates to restore degraded rainforest patches. The issue is close to my heart and something that I continue to learn and teach about. I’ve worked with the Vattakanal Conservation Trust to highlight their restoration work in shola/grasslands habitats changed by the widespread introduction of non-native tree species in the Palani and Nilgiri Hills. My 2005 article in Sanctuary entitled (by the editors) “the next big thing” described their work and the challenges of restoration in such sensitive habitats. In the article I mentioned the NCF work in the Anaimalais and have wanted to see it in person since.
- Lenny outside and inside of the Anaimalai Nature Information Centre (ANIC).
NCF, of course, does a good deal more than ecological restoration and they have research projects in the Western Ghats, North-East and Andaman, Nicobar and Lakshadweep Islands. Before going over to the Anamalais I contacted Shankar ‘Sridhar’ Raman and Divya Mudappa to set up a time to visit the NCF interpretation center. They were away but were able too hook me up with other NCF team members in Valparai. I first remember meeting Sridhar in Sengeltheri, (KMTR) in 1997 when he was conducting his dissertation study of birds in tropical rainforests of the Southern Western Ghats. I was on a short visit and was enjoying fine pre-monsoon weather to document different scenes including the view that led to the “Kalakad tree” image. Karthikeyan Vasudevan, of the Wildlife Institute of India, was also staying in the same hut conducting his research on amphibians. I remember being thoroughly impressed with their set up, passion for their work and individual studies.
Along the road to Valparai NCF runs what must be the most effective and informative interpretation centers in the entire Western Ghats. The Anamalai Nature Information Centre (ANIC) was our first stop on the Valparai plateau and Lenny and I were warmly welcomed. The location is a small bungalow immediately next to the main Valparai road in the Iyerpadi area. There are rooms dedicated to different habitats, species and challenges in the Western Ghats. A large number of attractively designed posters with beautiful digital pictures, write-ups and paintings by Maya Ramaswamy helps the viewer get a real sense for the range. They also have several publications for kids and adults and we left with lots of materials for the kids and school. I was happy to pick up an extra copy of Whitaker and Captain’s Snakes of India to replace the one that I had given to my Dhonavur friends. Our first point of contact at NCF was P. Jeganathan later Ananda Kumar talked to me about the plant nurseries. Jegan set us up to find the LTMs at the Puthuthottam estate utilizing the sharp skills of their watcher Joseph. Later that day he took us on a tour of the NCF nursery and interesting points near Valparai.
- Satish, one of NCF’s Valparai team members, shows off a three-year old Cullenia excelsa sapling that he is getting ready to transfer from the nursery to a degraded forest patch in the a nearby estate.
The NCF nursery was wet and misty on both days that I visited. Tata Tea has given them a section of one of their own tea nurseries to nurture rainforest trees that are collected from seeds on roadsides in forest fragments. These are documented, germinated and grown for the next 2-3 years. Once fragments are identified in tea-estate forests, sapling are taken from the nursery and planted during the monsoon season. The forest structure and conditions are carefully considered when choosing species to plant. Grazing has to be curtailed and invasive species removed when possible. Local communities, play a key role in education outreach and efforts to reduce collection of rainforest trees for firewood. A good deal of science and research goes into it and my observations were fleeting. Nevertheless, I came away impressed and hopeful in these small efforts to redress ecological ruin.
Lion Tailed Macaques (Macaca silenus) in mixed (plantation+ natural) forest near the Puthuthottam Estate hospital.
