European Phenology Campaign

Autumn 2025.

2025-12-17T14:11:02Z

Hello from Karlovac, Croatia, Primary school "Braća Seljan". Although more than half of birch is leafless, our four leaves are still holding on. They are all 2.5Y 8/12.

Autumn 2025.

2025-12-15T16:54:32Z

Hello from cold Karlovac, Croatia. Students from primary school "Braća Seljan" visited birch tree on 9th December and monitored that all four leaves changed colour 5GY 7/12.

Autumn 2025.

2025-12-15T16:38:30Z

Hello from Karlovac, Croatia, primary school "Braća Seljan". On 2nd December leaves on our birch has finally changed colour. All four leaves are 5GY 6/ 10.

Autumn 2025.

2025-11-30T20:57:51Z

Hello from "Braća Seljan" primary school., Karlovac, Croatia. This is an observation of a birch tree on November 26th. Unbeliveable, but the colour of all four leaves is still unchanged- 5GY 5/ 10.

Autumn 2025.

2025-11-12T15:28:55Z

Hello from "Braća Seljan" primary school., Karlovac, Croatia. This is an observation of a birch tree on November 11th. Today's air temperature is 5 C.
The color of all 4 leaves is still the same 5GY 5/ 10.

Autumn 2025.

2025-11-09T16:03:07Z

Hello from Karlovac, Braća Seljan Primary school, Croatia.
Observation on November 4. The leaves still didn't change the colour. They are all 5GY 5/10.

Autumn 2025.

2025-10-31T10:15:52Z

Hello from Karlovac! On 22nd of October leaves on our birch still
haven't changed colour. This autumn is suprisingly warm and daily
temeperatures are higher than 20C, so I suppose that is the reason.
Greetings from Karlovac.

Autumn 2025.

2025-10-23T13:59:54Z

Hello! On 15th of October 2025 the leaves on our birch are still the
same (5GY, 5/ 10). Although some other leaves turned yellow, the four
ones that we have choosen remain the same. So strange! Greetnigs from
Karlovac, Croatia!

Autumn 2025.

2025-10-12T20:11:36Z

Hello! On 8th of October it was 15 C in Karlovac. We visited aour birch
tree and nothing has changed since the last time. Leaves didn't change
its colour. It is still 5 GY, 5/ 10.

Autumn 2025.

2025-10-12T20:02:19Z

Hello from Karlovac! On 3rd of October our birch tree all the leaves has
the same colour- 5GY, 5/ 10. It was sunny and warm day.

Autumn 2025.

2025-09-28T19:41:54Z

Hello! On 23rd of Septembet we marked the branch on our birch, numbered
the leaves and did our first colour observation.

Autumn 2025.

2025-09-28T19:31:25Z

Hello! On 16th of September we visited our birch tree for the first
time. There are 10 of us, aged 8 to 10. We come from Karlovac, school
"Braća Seljan". This is a photo of us!

Spring 2025., OŠ "Braća Seljan", Karlovac

2025-04-25T06:20:51Z

Hello from Karlovac! On 16th of April the weather is warm and sunny. It is 23C. The lenght of leaves on our birch hasn't changed since the last time we measured it.

Spring 2025., OŠ "Braća Seljan", Karlovac

2025-04-14T09:53:45Z

On 11th of April Karlovac is warm and sunny. Our birch tree is full of green leaves.
Leaf 1- 56mm, leaf 2- 45mm, leaf 3- 50mm, leaf 4- 60mm

Spring 2025., OŠ "Braća Seljan", Karlovac

2025-04-04T14:43:13Z

Hello from Karlovac, Croatia. It is 10C on 1st of April 2025. On our birch LEAF 1 is 40mm, LEAF 2 is 30 mm, LEAF 3 is 34mm and LEAF 4 is 44mm.

Spring 2025., OŠ "Braća Seljan", Karlovac

2025-03-26T17:08:07Z

On 26th of March the temperature in Karlovac, Croatia was 13C. Leaf 1- 35mm, leaf 2- 26mm, leaf 3- 30mm, leaf 4- 40 mm.

Spring 2025., OŠ "Braća Seljan", Karlovac

2025-03-26T17:00:09Z

Hello from Karlovac! On 17th of March the temperature was 10C. Here are our mesurements.
Leaf 1- 8 mm, leaf 2- 5 mm. leaf 3 and 4- 6 mm

Spring 2025., OŠ "Braća Seljan", Karlovac

2025-03-11T17:25:20Z

Today is 11th of March. It is 15 C. The soil is wet. Buds on our birch are swelling.

Spring 2025., OŠ "Braća Seljan", Karlovac

2025-03-11T16:46:47Z

Hello everyone,

Greetings from Karlovac, Croatia!

We are very excited to be part of the Phenology Campaign once again! It is 4th of March and we have chosen a tree for the observation. It is a Silver Birch. The coordinates of our tree are 45.489911,15.549275E. Zhe weather is dry and sunny.

Autumn 2024., OŠ "Braća Seljan", Karlovac

2024-12-16T10:21:05Z

Pozdrav iz Karlovca! 10. prosinca temperatura je 3C u 12:30 sati.
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