> ## Documentation Index
> Fetch the complete documentation index at: https://docs.isometric.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Activities reference

> Every activity type available in Certify per protocol, with its time granularity, metadata, measurements and links

This page lists every activity type Certify supports, grouped by protocol. Your project only has the activity types belonging to its protocol and protocol version. For how to add activities, see [Add activities](/user-guides/certify/project-assets/add-activities).

## Overview

Each activity type below is described by the following attributes.

| Attribute        | Meaning                                                                                                                                                                                                                                                                              |
| ---------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| **Key**          | The identifier used in the API and in exports.                                                                                                                                                                                                                                       |
| **Time**         | The time granularity the type records, which determines the time columns in its CSV. **Date** takes `date`, **Timestamp** takes `time`, **Date range** takes `start_date` and `end_date`, **Timestamp range** takes `start_time` and `end_time`, and **None** takes no time columns. |
| **CSV columns**  | Every column of the upload, in order. Always download the template from Certify rather than copying these by hand, since they follow your protocol version.                                                                                                                          |
| **Metadata**     | The extra fields defined for the type. Fields with allowed values must use one of those values exactly.                                                                                                                                                                              |
| **Measurements** | The physical quantities recorded against the activity. Each has a quantity kind, a unit that its CSV column header states, and is either required in every row or optional.                                                                                                          |
| **Links**        | The other assets the activity connects to. Each link is a CSV column holding the related asset's reference ID, and the related asset must already exist before the upload.                                                                                                           |

Every activity type also takes a `name` and a `reference_id`, both required and not repeated in the tables below. See [Supplier Reference ID](/user-guides/certify/supplier-reference-id).

## Reforestation

Activity types for projects using the [Reforestation protocol](https://registry.isometric.com/protocol/reforestation/1.2), version 1.2.

### Field plot measurement

Tree measurements are used to quantify above-ground biomass (AGB) within each field plot, which in turn is used to quantify the carbon sequestered in the project area. Each tree measurement must have a unique reference ID, be linked to a specific field plot, and use one of the predefined tree type keys.

|        |                                        |
| ------ | -------------------------------------- |
| Key    | `reforestation_field_plot_measurement` |
| Time   | Date (`date`)                          |
| Upload | CSV                                    |

CSV columns, in order:

```
name,reference_id,date,tree_type,field_plot_id,Diameter at breast height (cm),Elevation (m),Height (m),Latitude (degree),Longitude (degree)
```

| Metadata  | Key         | Required | Allowed values                                                                                                                                                                                                                       |
| --------- | ----------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| Tree type | `tree_type` | Yes      | One of 580 tree type keys — 160 genus keys such as `GENUS_ABAREMA` and 420 species keys such as `SPECIES_DIPTERYX_ODORATA`. The full list is in [Supported tree types](/user-guides/certify/tree-measurements#supported-tree-types). |

| Measurement               | Quantity kind               | Unit     | Required | Description                                                                     |
| ------------------------- | --------------------------- | -------- | -------- | ------------------------------------------------------------------------------- |
| Diameter at breast height | `diameter_at_breast_height` | `cm`     | Yes      | The diameter of the tree at breast height (approx 1.3 meters above the ground). |
| Elevation                 | `elevation`                 | `m`      | No       | The elevation of the tree location.                                             |
| Height                    | `height`                    | `m`      | No       | The height of the tree from the base to the top.                                |
| Latitude                  | `latitude`                  | `degree` | No       | The latitude of the tree location.                                              |
| Longitude                 | `longitude`                 | `degree` | No       | The longitude of the tree location.                                             |

| Relationship | Related type                                                                 | Cardinality | CSV column      |
| ------------ | ---------------------------------------------------------------------------- | ----------- | --------------- |
| happens at   | [Field Plot](/user-guides/certify/project-assets/sites-reference#field-plot) | One to one  | `field_plot_id` |

## Enhanced Weathering in Agriculture

The [Enhanced Weathering in Agriculture protocol](https://registry.isometric.com/protocol/enhanced-weathering-agriculture/1.2) version 1.2 does not define any activity types, so the **Activities** section does not appear in the navigation of an Enhanced Weathering project. Its sites are documented in the [Sites reference](/user-guides/certify/project-assets/sites-reference), and feedstock spreading data is added as described in [Add feedstock](/user-guides/certify/add-feedstock).