Global plant diversity

Our latest paper (here) in the prestigious journal Nature Communications is about global patterns of plant diversity. Species richness is usually described with alpha diversity (number of species in a plot), beta diversity (change of species among plots) and gamma diversity (regional to continental number of species). This paper is about alpha diversity.

The number of species found in a plot is related to the plot size. As any chosen plot size is arbitrary, the question was to check how alpha diversity would change with different plot sizes (also called grain) and how the alpha diversity measured at different grains would be distributed over the world. The number of species was also correlated to climate, soil and topography.

Global maps of alpha diversity were produced from more than 170,000 plots worldwide. The number of species in these plots was extracted at three different scales (say small, medium and large).

The maps of alpha diversity worldwide classically show an increase of local diversity from the temperate to the tropical regions. However, the three grains do not exactly produce the same maps, which shows that alpha diversity is not accumulated at the same rate from region to region. The African forests have high coarse grain richness whereas Eurasian temperate forests have high fine grain richness. The cause of these differences are still unknown and among the potential candidates are: history, species assembly rules, selection.

India’s plant alpha diversity in general is intermediate with a regular accumulation of species from fine to coarse grain. The North-East and a small part of the Himalayas have a very high alpha diversity at small grain but not at coarse grain. Alpha diversity hotspots are small or non-existent even though the gamma diversity is intermediate in the Western Ghats and the assemblage unique due to endemics.

It should be noted that non-forest plots appear as data deficient in north India: is it because data could not be found online or because there are too few studies on vegetation?

Jean-Philippe Puyravaud

A tribute to Bellan, Forest Watcher

Bellan, Forest Watcher, on the right.


Nassim Taleb, one of my favorite authors, wrote about heroes in his book “The Black Swan”. He said something a bit startling: if an administrator had taken the proper safety steps, the destruction of the Twin Towers in New York may not have happened. This administrator would have been a hero but no one would have known because nothing would have happened in the first place. Heroes are characterized first by their sense of duty.

The term “wildlife hero” we hear too often has become overused. We see so much craving for fame in the little world of conservation that any designated wildlife hero will suddenly believe in a stratospheric status and never come back to earth.

Mr. Bellan, a simple forest watcher, who died at sixty a few weeks ago, was not into self-promotion. Of humble origin, he never expected rewards and he would have been astonished to see that people took an interest in him. He was from a family of shikaris and had a deep, intuitive understanding of wildlife.

The first time I met Bellan was when I had been charged by an angry elephant. People had burst fire crackers near our house and I wanted to tell them to stop disturbing the elephant which was around. Unfortunately, I did not know the elephant’s exact location and he charged on seeing me. It was a miraculous escape. Bellan came when we complained about the fire crackers and we told him the story. He also had escaped an attack. The elephant stepped on him, breaking a few ribs. It took him six months before he recovered from the shock, even though he looked tough. This was sort of healing for me to realize that to be unsettled under these circumstances was natural.

Recently, Bellan had to take charge of Rivaldo, the local elephant star. Rivaldo is radio-collared and constantly under supervision to make sure he does not get fed by people. Every time Rivaldo decided to come to drink at our tank, we could meet with Bellan. It was fascinating because he knew the jungle just like the old folks. We were so happy to see a person with whom we could share our ideas and be understood. For example, we hide when we see Rivaldo. So many of the forest staff who were noisy and fully visible to the elephants, mistook our behavior for something else. They thought we were frightened when in fact we just prefer elephants not to get used to human presence. Bellan understood why we were going away and he himself was quiet and inconspicuous.

Bellan told us that the anti poaching watchers were insufficiently trained to be in the jungle. We could not agree more with him. The watchers are a walking disturbance now armed with their mobile phones with which they keep on taking selfies and probably post the pictures on social media. We have seen watchers being charged when the provocation was completely avoidable. So, he trained them and did what he could given that he was in the lower rank of the hierarchy.

Earlier, Bellan was requested to follow Ronaldo who was the most powerful and aggressive tusker in the region. Ronaldo had been injured on his back the first time, and on the second time a flaming object was thrown on him. The elephant suffered and died in agony. Bellan was the man who was saying a tearful goodbye if you read “Tamil Nadu forester bids emotional goodbye to dead elephant link required. Watch a heart-wrenching video.”* His name never appeared in the paper. If I can speak for Bellan who is no more, his tears may not have been only because he was a sensitive guy who liked elephants, but also because many such incidents could be avoided. The newspaper said Bellan was a Ranger. He was only a Watcher. People of his capability don’t get promoted. And, yes, he was a hero.

Jean-Philippe Puyravaud.

*We never watched the video. We knew too well what it was to lose Ronaldo.

Low abundance and diversity of seabirds and cetaceans in the Bay of Bengal

This blog is a little a-typical for the Sigur Nature Trust because it is about a paper on marine birds. Notice how fast the fisheries are crashing in the Bay of Bengal. It should prompt immediate better management. Apparently, it does not. Too bad for our food safety.

Seabirds are top predators and an important component of the marine food web, and their abundance and diversity can indicate the condition of marine fisheries, upon which millions of people depend. According to the Central Marine Fisheries Research Institute, marine fish catch from India declined 9% in 2018 compared to the previous year, mainly due to reduced catch in West Bengal, Karnataka and Maharashtra (

There is paucity of data on sea bird and cetacean abundance and distribution in the Bay of Bengal Large Marine Ecosystem (BOBLME). To assess the abundance and diversity of these two taxa, which are critical for the functioning of marine ecosystems, a team led by Ravichandra Mondreti and David Gremillet carried out at-sea surveys within the Bay of Bengal from 2012 to 2014 (link to paper here). The surveys were conducted from 39 vessel-based observations where all seabirds and cetaceans were recorded over a linear distance of around 4,722 km. A total of 2,697 seabirds from 17 species and 1,441 cetaceans belonging to at least 8 species were recorded. Sooty Terns Onychoprion fuscatus (n = 2,282, 85% of all birds) and Wedge-tailed Shearwaters Ardenna pacifica (n = 327, 12%) predominated, whereas cetacean numbers were dominated by Spinner Dolphins Stenella longirostris (n = 772, 54% of all cetaceans) and Indo-Pacific Bottlenose Dolphins Tursiops aduncus (n = 533, 37%). Dolphins and Pacific Bottlenose Dolphins, accounting for 93% of cetacean sightings.  

The abundance and diversity of both groups was low compared to other tropical areas. This could result from low ocean productivity caused by stratification in the Bay of Bengal, human impacts such as disturbance, overexploitation of marine resources and long line fisheries, where seabirds form a significant bycatch. There is also a paucity of breeding sites for pelagic seabirds. Therefore conservation efforts need to be stepped up in BOBLME to maintain the viability of marine ecosystem functioning.

P. Davidar

The ultimate tragedy of the commons?

Some of our colleagues and friends who are social scientists think of us conservationists as neocolonialists and/or pro-capitalists when we say that forests should be more protected. They often view forests as an ill-managed resource because for them (i) forest management is inherited from the British colonial rule, (ii) the poor need to have control over their environment and (iii) if local people do not manage their environment, other forces will.

I am originally from working class and I am systematically grieved to find myself clubbed with bad guys proposing to rip-off the poor of their scant resources. It is funny that these views often originate from fairly privileged left-wing people. Not that there is anything wrong to be left-wing and privileged. But whether from working class or more privileged extraction, there is a danger in creating a narrative on the basis of self-righteousness and paucity of data. The examples of locally protected forests that demonstrate sufficient size and ecological viability are by far too rare. We have however access to ample scientific data showing beyond doubt that the biosphere is getting destroyed at a rapid pace. If the forest was really cut for the poor, then it would be a lesser evil.

I never believed that access to forest resources would carry the poor out of poverty. In the early 1990s, it was clear to my colleague Jean-Pierre Garrigues and I, that landless laborers were working for “rich” farmers to extract manure, fodder and non-timber forest products from the forest. A simple way to “help” the poor, would have been to provide regular jobs. But even today, thirty years later, many people have lost their income because of the COVID-19 lock down: there are still daily wage workers.

Where do the resources generated by deforestation go? Thomas Picketty, the author of “Capital in the Twenty First Century”, a must-read book, may have an answer. If you look at the figure below ( you can see that economic inequality has increased since the 1980s (and probably earlier). The figure shows the share of total income by the top 10%. This trend is of enormous magnitude with astounding social consequences.

It would be tempting to correlate the decrease of primary forest cover (for example here) with the increase of inequality. And I have a suspicion: like most economic activities, forest destruction may benefit the poor only marginally. This would be the ultimate tragedy of the commons.

Jean-Philippe Puyravaud

Greta Thunberg, Extinction Rebellion and the march of folly

Overgrazing is a problem, overgrazing is a problem, overgrazing is a problem – does anyone care?

Greta Thunberg, the teenager from Sweden who became a climate change activist, does not need any introduction. Everyone knows that she stopped going to school in 2018 because she thought she has no future since “nothing” was done to fight climate change. According to her, climate change may de-stabilize our civilization. She has established herself as a leading figure of protests worldwide.

Extinction Rebellion may not be so well-known because it is still limited to Europe, Australia and a few countries. This is a civil disobedience movement that attempts to force governments into action in order to protect species (including us humans) from extinction due to excessive environmental degradation.

Greta Thunberg is a heroine for many and a puppet for others. She is pictured in some media as acting for the “rich”. Extinction Rebellion, a movement of young people is labeled “cult”, “doomsday worshipers” and many other names. Even though Extinction Rebellion is attempting to remain peaceful, governments give stronger and stronger responses to their actions.

One may say that these movements by the youth are fashionable group reactions. Others argue that if we examined the situation rationally, we would not follow such extremes. This is ignoring the fact that government agencies have been looking rationally at climate change for 50 years. Appeals to change the business-as-usual routine have been by-and-large ignored. Most countries adopt minimal budgets to address climate change. Conservation is of lower priority. No amount of data, interpretation and demonstration has convinced decision-makers to act forcefully on the clear and present danger ensuing from the systematic destruction of the biophere.

Many scientists of various disciplines understand the peril posed to civilization. They are becoming more vociferous because deniers get most attention in the media. Biologists, who generally are not inclined towards activism are warning us clearly, on paper, against the environmental catastrophe which is unfolding now. This warning available here is signed by 23,000 of them from 180 countries. This should look more worrisome than Greta Thunberg and our children in the street but it is ignored.

Reason is one of the most powerful and likable qualities of the human species. It works very well in self-inquiry, debate and science. For example, science depicts a fairly good picture of the condition of our environment. However reasonable discussion does not work when one side only pretends to pay attention but does not care – for decades. When a debate proves to be impossible, other forms of interactions come into play even though they do not satisfy anybody.

Jean-Philippe Puyravaud

Incidents with elephants and deforestation

Located amidst imposing mountains in Karnataka with a perpetually misty landscape, Coorg is the place to be for all nature lovers.


Contrary to what is advertised, nature lovers might be a bit lost in Coorg.

We just published this paper “Deforestation Increases Frequency of Incidents With Elephants (Elephas maximus)” available here, in Tropical Conservation Science. It may be the first paper that shows a correlation between the intensity of deforestation and increased incidents with elephants.

The region this paper focused on was Coorg or Kodagu, in between the Nilgiris Biosphere Reserve and the Badra Tiger Reserve. In approximately 50 years, most private forests were transformed into coffee plantations. The Indian Forest Act did little to halt the degradation of forests. Today, the corridor between the Nilgiris Biosphere Reserve and the Badra Tiger Reserve is gone. Elephants remaining in this landscape are terrified, hungry and lost. They kill people and provoke destruction. To add to people’s difficulties, the price of coffee sometimes goes down, which is a reminder that monoculture may not be the best way to wealth. With global warming, the monsoon will probably become weaker, bringing less water and the “cleaning” of the forest may not bring the expected economic returns.

We avoided to use the word “conflict” to prefer the word “incidents”. Elephants are not in conflict with humans. They just attempt to survive in their former habitat that happens to be in between protected areas. The term “conflict” is convenient whenever we want to prove that elephants are responsible for a situation. But as we show in this paper, the only conflict is what we want to do with our world.

Jean-Philippe Puyravaud

We are all into it

Lantana camara undergrowth in the Mudumalai Tiger Reserve


We recently have published a paper: ‘Point intercept method for estimating biomass of invasive lantana (Lantana camara) in the Nilgiris, India’ in the Indian Forester (here). This paper is part of our student Muneer Ul Islam Najar’s Ph.D. thesis on the population dynamics of lantana in the Nilgiris Plateau.

I was astonished by the number of request for this paper. This study represents a good effort to estimate biomass with a bizarre method: it consist in counting the number of contacts a vertical pin will make with the plant in several sampling places. The number of contacts is proportional to the plant’s biomass as shown in this study. This method, quite cumbersome, can be used to estimate the degree of infestation of an area. There are other methods based on allometry (plant proportions) for example.

The interest in any publication on lantana is understandable. Lantana is originally from Central America and had invaded the jungles of India. Consequently, many people are interested in lantana, including us. A reaction we often get when we start with a conservation question is: “so and so is doing the same thing”. To be translated into: “why do you bother at all since someone else is already working on the problem?” Many students get cold feet when they hear such feedback and abandon their ambitions. In many ways, the question is valid: why reproduce someone else’s work? Science proceeds rapidly, it is better to focus on discoveries. Conservation moreover, does not receive a lot of money from governments and it is crucial to be effective. But science needs competition, conservation must have different voices and management often requires site-specific information. The chance of being totally redundant is consequently small.

Are we going to resolve the lantana invasion with this research? No. However, Muneer needed to measure the degree of infestation and he did it by exploring a new method. He also realized that in the Nilgiris, tree plantations, if managed properly, could become less infested. A student trained in plant population dynamics and new suggestions to planters and the Forest Department make a modest but useful contribution to a better environment management. So why not do it?

Jean-Philippe Puyravaud

Sigur Nature Trust small-grant 2019 for the study of household energy use in the Sigur Region


The villages of the Sigur Region, in the heart of the Nilgiris Biosphere Reserve, are located within a network of reserves. These reserves harbor open forest that produce little wood due to a dry climate. Many people rely on firewood and wood collection tends to further reduce the productivity of the forest. As a consequence, wildlife and ultimately people suffer from the severe forest degradation.

Understanding the rationality of energy choice and the willingness of communities to find solutions is essential for a regional plan for improved livelihood and environment management. To our knowledge, little has been done on this issue in this very important region for the conservation of emblematic wildlife. Specifically, the questions to be addressed revolve around the following:

  • Type of energies available and their cost
  • Consumptive and productive use value of the different types of energies
  • Socio-economy of users and the motives of their energy choices
  • Difficulties (cultural, economical, etc) to abandon biomass as energy
  • Willingness to participate to management programs

On the 15th September 2019, the Sigur Nature Trust will provide a small grant (Rs 60,000 maximum) to document these issues

The grant is exclusively reserved for students. Candidates should send:

  • their biodata
  • a proposal (maximum 3 pages)
  • a budget (1 page)
  • a scan copy of a certificate of registration in an Indian education institution

The successful candidate should be fluent in Tamil and have excellent quantitative skills from any suitable discipline.

By accepting the grant, the successful candidate also agrees to share data and provide a report to the Trust in a convenient format chosen by the candidate (M.A./M.Sc. thesis or Ph.D. thesis or report or preferably, a scientific publication). The Trust can provide additional support such as data analysis should the candidate request it. The Trust will first disburse half the grant value and the second half will be disbursed after a review conducted at the grantee’s convenience.

The deadline for the submission of proposals is the 1st of September 2019. Applications should be sent in PDF at the e-mail address:

Risk our lives or wait till the law is implemented?

Today is the second time I was seriously charged by an elephant because of the irresponsible behavior of people.

The first time was on 25th January at 10:20 am (these things tend to stick to memory). The personnel of a nearby school at Vazhaithottam came to the river near our house throwing loud fire crackers. I went to let them know they were elephants around and was charged very seriously by Cortes. This happened because I was looking for him on the wrong side and I could not see him early enough. I was probably three seconds from being killed if my wife hadn’t shouted at the top of her voice during the charge and also risked her life by running towards the elephant. Elephants get confused when they hear loud noise and tend to lose their focus of the target.

Cortes immediately after breaking the charge. Photo Peter Davidar.

It happened again today. We saw a group of seven people and a dog walking near the river again at 10:00 am coming from the Mavinhalla village. I went to advise them to leave. I barely had the time to ask them who they were and where they had come from, when I saw an elephant charging. I only had the time to shout “run”. Luckily, we all managed to reach the house safely, but if I had not gone at the risk of my life, they would have been casualties.

Group of tourists after the charge. One person is hidden, recovering. You can also suffer cardiac arrest…

Recorded human deaths due to an elephant charge due to human disturbance inflate the statistics of human-elephant conflict (HEC). However, as we can see here, there was no conflict. In the first case, a few local people wanted to have a good time near a stream across from a Reserved Forest. In this place they are bound to meet with elephants. In order to do what they want, they  regularly disturb threatened species – in a protected area. In the second case, the group of tourists came from a house that operates as an illegal guest house and absolutely everyone knows about it. Illegal business do not trouble themselves with visitors’ safety and environment regulation.

The question is: when is the law going to be enforced before someone is killed?

Jean-Philippe Puyravaud

Sigur Nature Trust small-grant 2019 for education and awareness

Children from the center of the Nilgiris Biosphere Reserve paradoxically have little incentives to know about their exceptional environment.

On the 15th September 2019, the Sigur Nature Trust will provide a small grant (Rs40,000 maximum) to undertake an awareness project in a local school (Mavinhalla or Masinagudi or Kargudi). The awareness project will describe the process of ecological succession. The project will also highlight the danger of overgrazing and overharvesting, and will emphasize the benefits derived from the knowledge and propagation of useful plants for medicine, art and income.

The grant is exclusively reserved to students or individuals with a track record. Candidates should send:

  • their biodata
  • a proposal (maximum 3 pages)
  • a budget (1 page)
  • a certificate of registration in an Indian education institution for students

By accepting the grant, the successful candidate also agrees to provide a report (maximum 5 pages) to the Trust in a convenient format chosen by the candidate. The Trust can provide additional support such as documents, photographs and videos should the candidate request it.

The deadline for submission is the 1st of September 2019. Applications should be sent in PDF at the address: