Indicator Specification

Phenology of plant and animal species

Indicator Specification
  Indicator codes: CLIM 023
Published 20 Dec 2016 Last modified 04 Oct 2021
8 min read
This page was archived on 04 Oct 2021 with reason: No more updates will be done
Trends in spring phenology

Assessment versions

Published (reviewed and quality assured)
  • No published assessments


Justification for indicator selection

Phenology is the timing of seasonal events such as budburst, flowering, dormancy, migration and hibernation. Some phenological responses are triggered by mean temperature, while others are more responsive to day length or weather. Altitude and the amount of urbanisation have an effect on temperature and, consequently, on phenology. Generally, so-called ‘spring advancement’ is seen in hundreds of plant and animal species in many world regions. Changes in phenology affect the growing season and, thus, ecosystem functioning and productivity. Changes in phenology are having an impact on farming, forestry, gardening and wildlife. Changes in flowering have implications for the timing and intensity of the pollen season and related health effects.

Climate warming affects the life cycles of all animal species. Populations at the northern range margins of a species’ distribution may benefit from this change, whereas populations at the southern margins may encounter increasing pressure on their life cycles. Mild winters and the earlier onset of spring allow for an earlier onset of reproduction and, in some species, the development of extra generations during the year. However, under unfavourable autumn conditions, the attempted additional generation can result in high mortality. This developmental trap has been suggested as the cause for the dramatic decline of the wall brown, a butterfly with non-overlapping, discrete generations, in Europe. In the case of a phenological decoupling of species interactions in an ecosystem (e.g. reduced pressure from parasitoids and predators), certain populations may reach very high abundances that attain or exceed damage thresholds in managed ecosystems. Desynchronisation of phenological events, such as shortened hibernation times, may deteriorate body condition, and interactions between herbivores and host plants could be lost, and may also negatively affect ecosystem services such as pollination. There is robust evidence that generalist species with a high adaptive capacity are favoured, whereas specialist species will be affected mostly negatively.

Scientific references

  • No rationale references available

Indicator definition

  • Trends in spring phenology


  • days/year

Policy context and targets

Context description

In April 2013, the European Commission (EC) presented the EU Adaptation Strategy Package. This package consists of the EU Strategy on adaptation to climate change (COM/2013/216 final) and a number of supporting documents. The overall aim of the EU Adaptation Strategy is to contribute to a more climate-resilient Europe.

One of the objectives of the EU Adaptation Strategy is Better informed decision-making, which will be achieved by bridging the knowledge gap and further developing the European climate adaptation platform (Climate-ADAPT) as the ‘one-stop shop’ for adaptation information in Europe. Climate-ADAPT has been developed jointly by the EC and the EEA to share knowledge on (1) observed and projected climate change and its impacts on environmental and social systems and on human health, (2) relevant research, (3) EU, transnational, national and subnational adaptation strategies and plans, and (4) adaptation case studies.

Further objectives include Promoting adaptation in key vulnerablesectors through climate-proofing EU sector policies and Promoting action by Member States. Most EU Member States have already adopted national adaptation strategies and many have also prepared action plans on climate change adaptation. The EC also supports adaptation in cities through the Covenant of Mayors for Climate and Energy initiative.

In September 2016, the EC presented an indicative roadmap for the evaluation of the EU Adaptation Strategy by 2018.

In November 2013, the European Parliament and the European Council adopted the 7th EU Environment Action Programme (7th EAP) to 2020, ‘Living well, within the limits of our planet’. The 7th EAP is intended to help guide EU action on environment and climate change up to and beyond 2020. It highlights that ‘Action to mitigate and adapt to climate change will increase the resilience of the Union’s economy and society, while stimulating innovation and protecting the Union’s natural resources.’ Consequently, several priority objectives of the 7th EAP refer to climate change adaptation.


No targets have been specified.

Related policy documents

  • 7th Environment Action Programme
    DECISION No 1386/2013/EU OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 20 November 2013 on a General Union Environment Action Programme to 2020 ‘Living well, within the limits of our planet’. In November 2013, the European Parliament and the European Council adopted the 7 th EU Environment Action Programme to 2020 ‘Living well, within the limits of our planet’. This programme is intended to help guide EU action on the environment and climate change up to and beyond 2020 based on the following vision: ‘In 2050, we live well, within the planet’s ecological limits. Our prosperity and healthy environment stem from an innovative, circular economy where nothing is wasted and where natural resources are managed sustainably, and biodiversity is protected, valued and restored in ways that enhance our society’s resilience. Our low-carbon growth has long been decoupled from resource use, setting the pace for a safe and sustainable global society.’
  • Climate-ADAPT: Adaptation in EU policy sectors
    Overview of EU sector policies in which mainstreaming of adaptation to climate change is ongoing or explored
  • Climate-ADAPT: Country profiles
    Overview of activities of EEA member countries in preparing, developing and implementing adaptation strategies
  • DG CLIMA: Adaptation to climate change
    Adaptation means anticipating the adverse effects of climate change and taking appropriate action to prevent or minimise the damage they can cause, or taking advantage of opportunities that may arise. It has been shown that well planned, early adaptation action saves money and lives in the future. This web portal provides information on all adaptation activities of the European Commission.
  • EU 2020 Biodiversity Strategy
    in the Communication: Our life insurance, our natural capital: an EU biodiversity strategy to 2020 (COM(2011) 244) the European Commission has adopted a new strategy to halt the loss of biodiversity and ecosystem services in the EU by 2020. There are six main targets, and 20 actions to help Europe reach its goal. The six targets cover: - Full implementation of EU nature legislation to protect biodiversity - Better protection for ecosystems, and more use of green infrastructure - More sustainable agriculture and forestry - Better management of fish stocks - Tighter controls on invasive alien species - A bigger EU contribution to averting global biodiversity loss
  • EU Adaptation Strategy Package
    In April 2013, the European Commission adopted an EU strategy on adaptation to climate change, which has been welcomed by the EU Member States. The strategy aims to make Europe more climate-resilient. By taking a coherent approach and providing for improved coordination, it enhances the preparedness and capacity of all governance levels to respond to the impacts of climate change.


Methodology for indicator calculation

Spring phenology shifts were investigated using both in situ observations and satellite-based normalized difference vegetation index (NDVI) datasets.

Methodology for gap filling

Not applicable

Methodology references

No methodology references available.


Data specifications

EEA data references

  • No datasets have been specified here.

External data references

Data sources in latest figures



Methodology uncertainty

Not applicable

Data sets uncertainty

Generally, observations for popular species groups such as vascular plants, birds, other terrestrial vertebrates and butterflies are much better than for less conspicuous and less popular species. Similarly, owing to (1) extensive existing networks, (2) a long tradition and better means of detection of rapid responses of the organisms to changes, and (3) general knowledge, phenological changes are better observed and recorded than range shifts. Projections of climate change impacts on phenology rely crucially on the understanding of current processes and responses. For most cases, only a few years of data are available and they do not cover the entire area of the EU but are restricted to certain well-monitored countries with a long tradition, for example, in the involvement of citizen scientists. Based on the short time series, the quantification of impacts and their interpretation thus has to rely on assumptions. One of the greatest unknowns is how quickly and closely species will alter their phenology in accordance with a changing climatic regime. Even experimental studies seem to be of little help, as they notoriously tend to underestimate the effects of climate change on changes in phenology.

When documenting and modelling changes in soil, biodiversity and forest indicators, it is not always feasible to track long-term changes (signal) given the significant short-term variations (noise) that may occur (e.g. seasonal variations of soil organic carbon as a result of land management). Therefore, detected changes cannot always be causally attributed to climate change. Human activity, such as land use and management, can be more important for terrestrial ecosystem components than climate change, both for explaining past trends and for future projections.

Rationale uncertainty

No uncertainty has been specified

Further work

Short term work

Work specified here requires to be completed within 1 year from now.

Long term work

Work specified here will require more than 1 year (from now) to be completed.

General metadata

Responsibility and ownership

EEA Contact Info

Hans-Martin Füssel


European Environment Agency (EEA)


Indicator code
CLIM 023
Version id: 3

Frequency of updates

Updates are scheduled every 4 years


DPSIR: Impact
Typology: Descriptive indicator (Type A - What is happening to the environment and to humans?)


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