Planting numbers tell you how much effort went in. Survival rate tells you whether it worked. It is the figure auditors, funders and, increasingly, regulators ask for, and it is simple to calculate once you have counted properly.
This guide explains the formula, how to count large sites without visiting every sapling, when to measure, and which monitoring method suits which job. For the bigger picture on why this matters in India, see plantation monitoring in India.
The survival rate formula
Survival rate (%) = live saplings counted ÷ saplings planted × 100
For example, a one hectare block planted with 1,100 saplings (the minimum density the Green Credit Programme’s 2024 rules used) where 770 are alive a year later:
770 ÷ 1,100 × 100 = 70 percent survival
The mortality rate is the remainder: 30 percent, or 330 saplings.
The arithmetic is easy. Getting the two inputs right is where most survival figures go wrong.
Getting the inputs right
Use the number actually planted, not the number planned. Record the planted count at planting time, per site or per block, with the date. If you only have a target figure, your survival rate has no real base.
Decide what “alive” means before you count. A sapling with green leaves is alive. One that has died back to the root but is resprouting may also be alive. A dry stem still standing is not. Write the definition down so every counter uses the same one.
Keep replacements separate. Replanting dead saplings, often called casualty replacement or beating up, is good practice. But if you count the replacements as survivors without adding them to the planted number, the survival rate looks higher than it is. Report original survival and replanting separately.
Record where you counted. A survival figure without a location cannot be checked. Note the GPS position or plot number for every count.
Sampling large sites
On a small site you can count every sapling. On large sites, count sample plots instead:
- Mark plots of a fixed size spread across the whole site, not only near the path or the gate. Audits have found plantations concentrated along pathways while interior patches were left out, and the same bias creeps into counts.
- Record the GPS location of every plot so the same plots can be counted again next time.
- Count live and dead saplings in each plot, and the number originally planted in it.
- Add up live and planted across all plots and apply the formula.
- Report the survival rate per block as well as the site average. A healthy average can hide one block that has failed completely.
The more plots you count, and the more evenly they are spread, the closer your figure will be to the true survival rate for the site.
When to measure
Most saplings that die do so in their first year, often in the first dry season after a monsoon planting. A count only at twelve months tells you about losses after it is too late to act on them. A practical schedule:
- At planting: baseline count, site boundary and species list.
- After the first monsoon: catches early losses from poor stock or planting.
- End of the first dry season: usually the hardest period. This is when watering, mulching or protection makes the biggest difference.
- Twelve months: the first-year survival rate most reports use.
- Every year after that: until the trees are established, typically three to five years. The Green Credit Programme’s revised methodology only counts trees that survive beyond five years.
Comparing monitoring methods
Field counts
A trained team counting sample plots gives the most direct survival figure. It is also slow and expensive across many sites, and the result depends on who counted and how carefully. Field counts are best used to check a sample of sites, or to look at a problem another method has flagged.
Geotagged photos
Mobile apps that stamp each photo with GPS and time are now common. Delhi’s DDA adopted one in 2026 for its plantation campaign. Geotagging proves a site exists and was visited on a date. A photo of a few healthy saplings near the road does not prove the whole site is healthy, so photos work best alongside counts.
Drones
A drone flying a site at low height produces imagery sharp enough to see individual crowns, and software can count trees from it. In Odisha, a CAG audit used a drone survey to find that only 1,837 of 10,000 recorded plants were alive. Drones need a pilot and flight permissions, so most programmes fly them a few times a year rather than continuously. Very young saplings with small crowns are harder to detect than established trees.
Satellite NDVI
Sentinel-2, a free European Space Agency satellite, photographs the ground in visible and infrared light every few days. Healthy leaves reflect near infrared strongly; dry or dying ones do not. The difference is expressed as NDVI, the Normalised Difference Vegetation Index. Sentinel-1 radar adds readings through monsoon cloud.
Each satellite square covers 10 metres, so this method does not count saplings. What it does well is watch every part of every site on the same schedule, and show you when one block’s readings start falling while the rest hold steady. That is the signal to send a drone or a field team, while there is still time to save the trees. See how satellite tree monitoring works for the detail.
| Method | Counts single trees | Covers every site often | Cost per extra site |
|---|---|---|---|
| Field plots | Yes | No | High |
| Geotagged photos | Partly | No | Medium |
| Drone | Yes | No | Medium |
| Satellite | No | Yes | Low |
Most reliable programmes combine them: satellite to watch everything, drones and field plots to count and confirm.
What a good survival rate is
There is no national benchmark that applies to every species and site, but some programmes now set one in their contracts. NHAI’s plantation guidelines tie highway contractors’ payments to 90 percent sapling survival. As another reference point, a report by the Supreme Court’s Central Empowered Committee found that survival rates states reported for compensatory afforestation from 2019-20 to 2023-24 ranged from around 40 percent in some states to as high as 98 percent in others.
What matters is that you set a target before planting, write it into the agreement with whoever plants and maintains the site, and measure against it with dated evidence. A survival rate that was never measured is not a high one or a low one. It is just unknown.
A simple survival report
For each site, a survival report should include:
- Site name, boundary and area
- Species planted and number planted, with date
- Survival rate at each check, with the date and method used
- Survival by block or plot, not just the site average
- Number replanted, reported separately
- Who measured, and whether they were independent of the planting partner
- Images or data that back up each figure
Get Zero builds this report for every site you run, with a satellite check every week, drone tree counts where you need them, and a WhatsApp alert when a block starts to dry out. If you need survival figures for CSR reporting, read CSR plantation monitoring, or book a demo to see your own sites.
Common questions
How do you calculate the survival rate of a plantation?
Divide the number of live saplings counted by the number of saplings planted, and multiply by 100. If 1,100 saplings were planted and 770 are alive, the survival rate is 70 percent. Count against the number actually planted, and do not include replacement saplings in the live count unless you add them to the planted count too.
What is a good tree survival rate?
There is no single national benchmark. Survival rates reported by Indian states for compensatory afforestation between 2019-20 and 2023-24 ranged from about 40 percent to over 90 percent. Set a target in the project agreement before planting, based on the species, site and maintenance budget, and measure against it.
When should tree survival be measured?
Take a baseline at planting, then check after the first monsoon, at the end of the first dry season, at twelve months, and every year after that until the trees are established, typically three to five years.
Can satellites measure tree survival?
Free satellites such as Sentinel-2 see the ground in 10 metre squares, so they measure vegetation health across groups of trees rather than counting single saplings. They are good at spotting where a site is declining. Drones or field plots are used to count individual trees.