Friday, February 15, 2008

India's Tigers and Forests

I have been blogging quite a bit about the state of India's wildlife and forests. There has been a lot of news about this topics lately. Not all of it bad. Recently the Indus dolphin was sighted in Punjab river Beas after the gap of about 70 years. But overall the news has been depressing. Bharatpur bird sanctuary has virtually dried up. According to the latest census the tiger numbers in the country are now thought to around 1400 only, much below the earlier figure of about 3000 given by the government. And there is more bad news of the state of the forests. The latest census of the Forest Survey of India reveals that between 2003 and 2005 India lost about 700 sq km of prime forest land and suffered lots of degradation of dense to moderately dense forests. By a coincidence I had posted on this topic a few days before this report (2003-2005) came out. That post used data from an earlier census (2001-2003). That census showed that forest cover has actually increased by around 2700 sq km. But the devil is in the details. All that "growth" is either an artifact of better mapping due to improved satellite resolution or counts monocultures planted on degraded land away from any critical wildlife habitats. The core forests in and around tiger reserves for example continue to vanish and become degraded. Afforestation is not being directed to where it is most needed. I had used the Nameri tiger reserve in Assam to illustrate this point using images more recent that those used in the 2003 survey. Now this latest report confirms that prime forest areas are shrinking.

All over the world, not just India the basic problem has been that population pressures have altered the landscape in often irreversible ways. Contiguous forested areas have become fragmented. They are now islands surrounded by human presence and activities. In India nowhere is this illustrated with more clarity and devastating realization than where the Himalayan foothills grade into the north Indian plains. Below image shows this situation where the ranges suddenly give way (green dotted line) to irregular jagged pieces of forest, isolated from other such pieces, islands surrounded by intense agriculture land use.

The brown dotted polygons mark the approximate boundaries of the Dudwa tiger reserve in Uttar Pradesh. Three patches of forest which are becoming increasingly fragmented and frayed at the edges literally. How do you manage healthy tiger populations is these isolated islands? They are few 100's of sq km large, able to sustain a few ten's of tigers at most in each of the forest patches. How do you ensure a healthy gene pool with such small numbers? Some years ago when I was living in Florida, wildlife authorities were faced with a similar problem with the Florida panther. A small population showing signs of debilitating health effects from inbreeding. So, the Texas cougar a close relative of the panther was introduced in the Florida habitats of the panther. The results are encouraging. Florida panther populations today are healthier. Increasingly it is not going to be enough to just manage the physical aspects of the ecosystem. Our wildlife management plans currently claim to focus on afforestation, resolving human animal conflicts at forest margins, controlling logging and poaching. These are worthy goals. Poaching especially is suspected to have disproportionately contributed to the recent decline in tiger numbers. But even if our reserves become well protected against poaching we have to live with the reality that most of our tiger habitats are never going to connected to each other again and animals trapped in isolated habitats will need more help. We will have to manage their biology for them as well. Conservationists often talk about setting up migration corridors but take a look at the above image of Dudwa which for administrative purposes is one tiger reserve. The three forest patches are separated by 10's of km of intense agriculture land use. It is inconceivable that we can change land use and relocate humans on this scale. Most reserves in India are now separated by 100's of km of no forest areas and migration corridors cannot be thought of as a general solution to habitat isolation. In this context saying India has a total of 1400 tigers or 3000 tigers or some other number becomes less meaningful than assessing what viable population can be maintained in each of the forest islands across which natural migration and gene flow is now impossible. By such separate assessments may come the unpleasant knowledge that 1500 to 2000 is the total healthy population that can be sustained given the limited amounts of forests left. Off course this number will be hopefully much more, but to come to a stage where we are in a position to develop a tiger management plan backed by some hard science we will need increasingly focussed biological information on individual tiger populations. This means developing genetic databases of tigers to understand the genetic structure of populations. Regular screening for signs of inbreeding and setting up a well funded programme for induced gene flows across our tiger reserves. Are we geared up for a biological management plan for tigers?

What has been the reaction of the government to the recent report that 700 sq km of prime forest has been lost?

"Overall, the decrease is insignificant. It is not worrying as India's forest cover has more or less stabilised and ranks number 10 globally on a per capita basis," said Devendra Pandey, director-general of Forest Survey of India.

It is a statement only an Indian bureaucrat can make. Factually correct in a very narrow sense but showing a contemptuous arrogant indifference to the ground ramifications of the finding. Pretending everything is fine because we rank number 10 globally on a per capita basis. How on earth is that hollow boast supposed to help the tiger? Dismissing the real loss of prime habitat by pointing out that our forest cover has more or less stabilized. In an earlier post I pointed out how meaningless this stabilizing is in the context of the health of critical wildlife habitats. Afforestation is simply an exercise carried out to balance the books of the ministry of environment and forest. Let's take another look at how this "stabilization of forest cover" is working out. Below is a forest cover map of Buxa tiger reserve in West Bengal. This data was complied from 2001 satellite images.

Source: Forest Survey of India

Green is dense to moderately dense forest and yellow is open forest which has about 10-40% forest cover. Look at the area around the red arrow. And compare it with a close up below of the same area taken in 2006.

If our afforestation programme really was meaningfully designed, this open forest shown in 2002 should have been targeted for improvement. The reality? By 2006 the entire area has been converted to farmland. "Ground Truthing" in remote sensing parlance refers to the validation of automated classification algorithms used in land cover mapping. Over here the term ground truth has taken on a much more urgent meaning. The truth is that our prime ecologically rich forest areas are disappearing but the government doesn't seem to care. Through its reports it is misleading it's citizens by creating statistical illusions of forest cover "balance" and "stabilization". As long as somewhere far away an equivalent amount of area is greened with monoculture plantations the forest department goals of "stabilizing" forest cover will be met and a false victory proclaimed.

Write to your state forest department and demand action. The link to the Maharashtra forest department is : Maharashtra Forest Officials

See also:

India Gains Forest Cover, But....
Bharatpur Bird Sanctuary Dries Up
Indus Dolphin Sighted in Punjab

1 comment:

  1. Rather grave charges to make - and deffinitely worthy of making given the gravity of the sitution.
    Are you sure though you have reserve boundaries correctly traced - all seemingly forested land may not necessarily be in the charge o forest officials. And while letting such a big chunk of woods turn into farms ishould raise eyebrows I think you should responsibly ascertain the actual ownership status of the land in question