Your observations in nature can be really valuable! The participation in the project is divided into two parts: choosing the place where you want to make the phenological observations (STEP 1) and go to the site and make these observations using our online form or the iNaturalist app (STEP 2). With the information below you have everything you need to participate on your own, but if you write to us at the project’s email address, info@ritmenatura.cat, we can call you by phone and guide you personally.


From PhenoTandem we have selected approximately 30,000 areas of interest throughout Catalonia, of which good satellite images are available. These are squares of 60x60 m side composed of the same species of plant in each case. The set of species includes deciduous forests, evergreens, fruit trees, irrigated crops, scrubs and meadows and reeds. On the project website you will find a map of the areas of interest where you can choose the place you want. Surely there is one very close to your home!

Screenshot of the PhenoTandem area of interest map


  • To ensure the correct operation of the map, we recommend that you access it from a computer.
  • When you access it, the first thing that appears will be the empty map, but after a few seconds the 30,000 points will be loaded. There are many and they will appear on top of each other, so you have to zoom in on the approximate place that interests you. This way, as you get closer to the area, you can see the points better individually.
  • To navigate the map, you need three buttons that you will find in the top menu bar:
  • Hand (move sight): click on this button to move around the map.
    Magnifying glass (zoom of window): it is used to make a box in the area where you want to zoom. The + or - zoom functions are also translucent to the left of the map by hovering the mouse over them.
    Arrow (consultation by location): it is used to select the place where you want to consult the coordinates.
  • Once you are on the area you want, click on each icon to see the information. A box will open, where you can consult the species, the coordinates, the link to the online form to make the observation and the link to Google Maps with the route to get to that point.
  • We recommend you to use the map to choose the place or places you want to go and save the Google Maps link on your mobile phone or tablet so that you can get there. Also write down the species of plant to know what you are observing.
  • Don’t worry about whether your points have already been observed. As more data we have of a place, it is better for the project, so choose the points that suit you best!


Once you are at the place you have chosen, all you have to do is capture the phenological observation. Note that the coordinates are in the center of a 60x60 m square, so you don't have to be exactly above the coordinate. To make the phenological observations we have created an online form specially designed to facilitate the collection of data from the mobile or tablet.

Screenshot of the PhenoTandem online form.


  • Our online form submits the data to iNaturalist, a citizen science platform for recording biodiversity data. There is where we collect all the phenological observations. Therefore, in order to use the online form, you must have a user account in iNaturalist.
  • When you enter to our online form, the first thing you will be asked to do is log in to iNaturalist. If you already have an account, sign in with your credentials. If you don't already have one, sign up with an email address and password from the option provided on the same form. When you sign in, we advise you to check the 'Remember me' box so you don't have to enter your credentials every time.
  • Once you have logged in, the form will guide you through the steps to make the phenological observation:
    1. Photograph:
    2. Attach one or more photographs that accurately reflect the phenological state of the species you are observing. We recommend that you take a detailed photo of the leaves and another one general of the plant or tree. Make sure the images are not blurred.
    3. Species:
    4. Choose from the list the species you are observing.
    5. Phenophase:
    6. Choose from the list the phenophase of the species. Now in autumn, you only have to decide between four options:
      • Leaves still green: the trees present the most part of their leaves in a green color.
      • Onset of senescence in the plant/tree (-50% of yellow, reddish or dry leaves).
      • Full senescence on the plant/tree (+ 50% yellow, reddish or dry leaves).
      • Falling leaves on the plant/tree (dry leaves are falling)
    7. Place:
    8. As soon as you arrive to the place, activate the GPS of the phone or tablet so that the form records the coordinates automatically. We therefore recommend that you choose ‘automatic’ or ‘auto. more accurate’.
    9. Date:
    10. The date of your observation is a very important variable to know if the phenological phase change of the species you are observing occurs at the expected time or has been delayed or advanced compared to previous years. The default option will mark the day and time you send the data automatically by grabbing it from your phone or tablet, so you don't have to do anything.
    11. Advanced (optional):
    12. If you want to keep track of the same individual or area throughout the year (beyond PhenoTandem), fill in the corresponding field with a code created by you that allows you to identify recurring observations you make. If you make observations from the same group, identify yourself in the field prepared for this purpose and we will be able to group your data.
  • Once you have completed the first five steps, you will be able to send the data. When the submission has been made correctly, you can repeat this process as many times as you want using the "new observation" button. You can also share the observation via Twitter and consult the data you have sent via the link to iNaturalist that will appear to you.
  • Our online form requires an internet connection. In case that there is no mobile coverage where you are, you can upload observations directly from the iNaturalist app, as it can be used without using data. Later, you can sync the app once you have internet access via mobile data or Wi-Fi. To use the app available for Android and iOS, you can download this simple iNaturalist tutorial in pdf.


The cards of each species of plant or tree are available on our website so that you can resolve any doubts you may have about their identification or what you need to look for to find out what phenophase it is.

And remember, you can contact us at the email info@ritmenatura.cat and we will contact you to guide your work during your participation. Thank you!

Collaborate with us by becoming an observer!!