Tree Survival Rate Formula: A Plantation Guide for India

CSR managers, mine environment teams, CAMPA forest-division staff, and ESG analysts preparing BRSR notes all get asked the same question after a planting drive: how many are still alive? The tree survival rate formula is simple. The hard part is the number underneath it: what counts as "planted," what counts as "alive," and whether someone else could walk the site and get the same count.

This guide covers the formula, a worked example, casualty replacement, counting methods, resurvey timing, common mistakes, and what official documents do and don't say about survival norms.

Takeaways

• Survival rate = (surviving saplings ÷ saplings originally planted) × 100, for the same block, the same cohort, and a stated survey date.
• Keep casualty replacements as a separate count. Report original-cohort survival and current stocking side by side. Don't merge them.
• We did not find one all-India survival percentage in the national CAMPA guidelines we read. Norms vary by programme, state, and contract. Use the figure written into your own sanction, MoU, or work order.
• Geo-tagged resurveys tie each count to a place and date, so it can be rechecked.

The basic survival rate formula

For one plantation block and one planting cohort:

Survival rate (%) = (number of surviving saplings ÷ number of saplings planted) × 100

Three definitions make the formula usable.

• Planted means saplings actually put in the ground in that block and season, as recorded on the planting day. It does not mean pits dug, saplings procured, or the target in the proposal.
• Surviving means alive on the survey date by a rule you've written down in advance, for example green foliage, live buds, or green cambium under a light bark scratch. For deciduous species surveyed in the leafless season, record "uncertain" and recheck rather than guessing.
• Survey date matters because survival falls over time. "82% at 12 months" and "82%" are different claims.

A third-party evaluation of CAMPA works in Odisha, submitted to the Odisha State Forest Department in June 2023, uses the same structure at plot level: the number of surviving plants in the sample plot (out of those planted) divided by the number of trees planted in the sample plot, times 100. It then averages the site-wise values for each division.

Worked example (illustrative numbers only)

The figures below are invented to show the arithmetic. They are not data from any real plantation, and they are not Aranyix statistics.

A company plants a 4-hectare CSR block in July. The planting register records 2,000 saplings planted.

At the 12-month resurvey, the field team counts every sapling in the block:

Status at 12 months	Count
Alive and healthy	1,540
Alive but stressed (browsed, wilting, termite damage)	100
Dead or missing	360
Total accounted for	2,000

Survival rate = (1,540 + 100) ÷ 2,000 × 100 = 82%.

Two checks before you publish that number:

1. Does the total accounted for equal the number planted? If the team found only 1,900 positions, record 100 as missing (dead for the calculation). Don't shrink the denominator.
2. Is "stressed" counted as alive? Here it is. Say so in the method note and report the stressed count separately.

Combining several blocks

If a programme has several blocks, pool the counts. Don't average the percentages.

Illustrative: Block A planted 5,000 and has 4,500 alive (90%). Block B planted 500 and has 250 alive (50%). The simple average of the two percentages is 70%. The pooled rate is (4,500 + 250) ÷ (5,000 + 500) × 100 = 86.4%. The pooled figure answers "what share of all the saplings we planted is alive." Show the block-level rates as well, because the average hides Block B.

Some state reports publish weighted survival percentages. In West Bengal's CAMPA monitoring report 2020-21, division totals work out as area-weighted averages. If your authority uses a weighted method, follow it and name it.

Casualty replacement: keep it as a separate count

Replacement planting, also called casualty replacement, beating up, or gap filling, means planting new saplings where the first ones died. The national CAMPA guidelines on preparing Annual Plans of Operation list, under post-planting maintenance, "replacement planting/casualty replacement/Gap Filling" for cases of low survival or more casualties.

Continuing the illustrative example: the company replaces all 360 casualties in the second monsoon. The block now holds 2,000 living saplings. It would be wrong to report "100% survival."

Report two figures:

Measure	Formula	Example
Original-cohort survival	Original saplings alive ÷ original saplings planted × 100	1,640 ÷ 2,000 = 82%
Current stocking	All living saplings (original + replacements) ÷ design count × 100	2,000 ÷ 2,000 = 100% of design

At the next resurvey, track replacements as their own cohort with their own planting date. If 60 of the 360 replacements die, replacement survival is 300 ÷ 360 × 100 = 83.3%. Link each replacement to the position it filled, so the record shows what died, when, and what went in its place.

If your contract defines survival differently, for example as stocking after replacements, write that definition next to the number.

How to count: full census or sampling

Full census

Count every sapling in the block. This is the most direct method and is realistic for small CSR blocks, avenue or linear plantations, campus green belts, and any site where each sapling already has an ID or GPS point.

Walk the rows in a fixed pattern. Mark each position alive, stressed, dead, missing, or replaced. It should reconcile with the planting register.

Sampling

For large blocks, count a sample and estimate. A sample result is defensible when:

• Plots are chosen randomly before the field visit, not picked on the day near the road or the gate.
• Plots are marked and geo-located, so a reviewer can find the same plots.
• The planted count inside each plot is known, from the planting design (spacing × plot area) or from a planting-day record.
• The sampling intensity is stated, as a share of area or number of plots.
• The result is labelled as an estimate for the block, with the sample size.

The West Bengal monitoring report is a public example. It lays a grid of 50 m × 50 m quadrats over the plantation map, picks plots with a random number table, marks plot corners on the ground and records their geo-location, enumerates every plant in each plot, and checks the area by traversing it with GPS. It gives a sampling intensity of 7.5% of area for first-year plantations. That's one state's method, not a national rule, but it shows the documentation a reviewer may expect.

Illustrative sample calculation: eight random plots in a large block contain 400 planted positions between them. The team finds 332 alive. Estimated block survival = 332 ÷ 400 × 100 = 83%. That's an estimate from eight plots. Report it as one.

When to resurvey

We did not find a single national resurvey schedule in the sources we read. What the documents do say:

• The national CAMPA APO guidelines say internal monitoring should be done annually, by officials independent of the team that did the work. They also note a National Authority direction (13th Executive Committee) that KML files and geo-coordinates of afforestation works be uploaded with photographs taken before plantation, after plantation, and thereafter annually.
• They also say at least 50% of the work should be verified by the Divisional Forest Officer at peer-group level.
• The West Bengal report refers to classifying plantations by 1st, 3rd, and 5th year when monitoring them. That's that state's practice.

For CSR and mining programmes, a practical pattern is a planting-day baseline, a resurvey after the first monsoon and first dry season, then at least once a year for the agreement period. Resurvey in the same season each year so leaf-fall doesn't distort the comparison.

Common mistakes

• Wrong denominator: dividing by pits dug, saplings procured, or the target instead of saplings planted.
• Replacements counted as survivors: reporting 100% after gap filling.
• Averaging percentages across blocks of different sizes instead of pooling counts.
• Convenience sampling: counting only plots near the road or gate.
• No date: a percentage with no survey date or plantation age.
• Leafless equals dead: recording dormant deciduous saplings as casualties.
• Overwriting history: replacing last year's status instead of adding a new record.

Official survival norms: what we could and couldn't verify

We did not find one all-India minimum survival percentage in the national CAMPA APO guidelines. They require survival and growth data to be recorded and monitored, and leave the range of inspection to state norms.

Some state documents report bands. The West Bengal CAMPA monitoring report 2020-21 classes survival of 90% or more as "category A" and 75% to 89% as "category B," and its preface calls survival above 50% in a five-year-old plantation very good. Those are that report's classifications, not a national standard.

Norms vary by programme, state, funder, and contract. Use the definition and threshold in your sanction order, EC or FC condition, CSR MoU, or work order. If none is written, agree one before planting.

How geo-tagged resurveys make the number defensible

A survival rate is a claim about specific saplings in a specific place. It holds up when a reviewer can trace it:

• Location. Each sapling or sample plot has a GPS point; each block has a boundary. The next survey visits the same positions.
• Date and surveyor on every status record.
• Photo evidence linked to the sapling or plot ID for that visit.
• Status history. Planted → alive → dead → replaced is kept, not overwritten.
• Reproducible arithmetic. The export shows the counts, the definition, and census or sample.

This is the core of geo-tagged tree plantation records for CSR and of CSR tree plantation survival tracking.

Survival rate checklist

Use this before any survival figure goes into a CSR report, BRSR disclosure, EC/FC compliance note, or funder update.

• Planting register lists block ID, boundary, species, planting date, and number planted.
• "Alive," "stressed," "dead," "missing," and "replaced" are defined in writing.
• Denominator is saplings actually planted, not pits, procurement, or target.
• Census or sample is stated. For a sample: random selection, plot IDs, plot locations, sampling intensity.
• Every counted sapling or plot has a GPS point and a dated photo.
• Counts reconcile: alive + stressed + dead + missing = planted.
• Replacements are a separate cohort, linked to the positions they filled.
• Original-cohort survival and current stocking are reported separately.
• Survey date and months since planting appear next to the percentage.
• The threshold you compare against is quoted from your own sanction, condition, or contract.
• Blocks not resurveyed this round are listed.

Where Aranyix fits

Aranyix keeps the record behind the formula: a geo-tagged tree register, survival resurveys, photo evidence tied to each visit, and exportable audit-prep reports that show the counts and the method. See plantation MRV software in India.

Programme workflows are on CSR plantation, mining greening, and CAMPA afforestation. When the planted count is still a claim to check on sample plots, tree plantation verification in Estate & Forest Watch freezes that claim and reconciles it with field observations. Aranyix doesn't decide whether your figure meets a condition, and doesn't file on any government portal for you.

Important — honesty box Aranyix provides plantation MRV, audit-prep evidence, and modeled estimates only. We do not issue Verra, Gold Standard, or other registry credits. We do not issue Green Credits. Aranyix is not a certification body, not a registry, and not a government-approved or empanelled tool. We do not file reports on e-Green Watch, PARIVESH, or any other government portal for users. Any survival threshold comes from your own sanction, condition, or contract. Modeled CO₂e stays labelled as an estimate.

Sources

• National Authority (National CAMPA), MoEFCC, guidelines for preparation of Annual Plan of Operations by State/UT CAMPAs, Chapter 2 (post-planting maintenance, including casualty replacement), Chapter 5 (monitoring, verification, and the 50% DFO verification line), and Chapter 7 (Executive Committee directions on KML files and annual photographs): nationalcampa.nic.in PDF. The live host timed out during drafting, so the text was read from the Wayback Machine copy of 15 January 2026.
• West Bengal Forest Directorate, Research, Monitoring & Development Wing, CAMPA Plantation Monitoring Report for the State of West Bengal, 2020-21, dated 05.06.2021, hosted by National CAMPA: nationalcampa.nic.in PDF (read via the Wayback Machine copy).
• Evaluation of Projects Undertaken under CAMPA in the state of Odisha (2017-18, 2019-20 and 2020-21), final report, June 2023, submitted to the Odisha State Forest Department, section 3.4.4 (survival rate formula): campa.odisha.gov.in PDF.