Welcome to the learning software SITAS
Press the 'F' key to start the full screen mode, 'ESC' to exit the full screen mode.

In the course of the program several quiz questions are waiting for you.

Notes on navigating:
  • Arrow keys left - right: Thematic sequence
  • Arrow keys up - down: detailed information
  • Menu: Select the topic
  • The progress of the program is indicated by the page numbers and bars at the bottom.
"The future can best be predicted if you design it yourself."

Alan Cay (US Computer Scientist)

What is SITAS about?

Biodiversity, that is the diversity of animal and plant species, their habitats and genetic diversity, is exposed to increasing risks.

A total of 105,000 species are on the "Red List" of the World Conservation Union (IUCN), 28,000 are considered directly threatened with extinction. However, ecosystems with rich diversity are our livelihoods because they are more stable over the long term than low-species ecosystems.

Are we dependent on speculation when it comes to the question of the future?

SITAS shows how uncertainties and risks are dealt with in science.

SITAS was developed in close collaboration between science and school.

What does the scientist say?

Prof. Josef Settele, Helmholtz-Centre for Environmental Research ‐ UFZ

Here's the teacher's opinion:

Biology teacher Dr. Sven Pompe

The diversity of insects is declining

Green-veined White
Green-veined White Pieris napi
The analysis of long-term trends in Germany (last 50 to 150 years) of about 7,000 species from 24 insect groups shows (Ries et al., 2019):
  • In 45% of the species, the population is declining.
  • In all insect groups there are more species with decreasing trends than with increasing ones.
  • In butterflies, 64% of species show decreasing trends.
Honey bee Apis mellifera
Short-term trends in Germany (last 10 - 25 years) were analyzed for about 1,500 insect species (Ries et al., 2019).
  • 23% of species have declining and 44% consistent trends.
  • For 30% of the species, there is currently no adequate database available.
  • For ants, 92% of species have declining trends.
  • For butterflies and bees, it is 40%.
P. nausithous
Dusky Large Blue P. nausithous
Analyzes of the World Biodiversity Council IPBES (Settele 2019)
  • Insects are the most important pollinator group.
  • The number, variety and health of insects are threatened.
  • Causes include changes in land use and landscape structure, climate change, pollution, pathogens, genetically modified plants and invasive alien species.
Cornfield with field flowers
Options for action are according to IPBES (Settele 2019):
1. Improvement of the current conditions
  • for example, by creating flower strips along fields
  • Encouraging pollinator-friendly practices among farmers (for example, suitable mowing regime)
  • Improvement of beekeeping (e.g. disease control, preserving genetic diversity)
Field research
2. Transformation of agricultural landscapes
  • Support for cultivation systems that promote biodiversity
  • Support for organic farming
  • Restoration of near-natural habitats (also in cities)
3. Improving society's relationship with nature by integrating diverse forms of knowledge and values into management and administration.

Our example: Butterflies

Kleiner Sonnenröschen-Bläuling
Aricia agestis
Butterflies are the second largest group of insects (after beetles). There are about 200,000 species worldwide.
By the way, most moths are nocturnal: Of the 3,750 species of butterflies and moths in Germany, only about 180 species are butterflies.

But the question arises:

Duerre in Mitteldeutschland 2018
Drought in Central Germany 2018. Dry pond in Leipzig.
Will the Brimstone and other butterflies still flutter across our meadows in thirty years' time?
That's not so sure, because:
As a result of climate change, intensive agriculture and development, more and more habitats of animals and plants are being destroyed in Europe.

Butterflies are indicators for biological diversity.

Lesser purple Emperor
Lesser purple Emperor Apatura ilia
  • Many species can be easily detected and determined.
  • Their life cycles and habitats are well known.
  • The development from the egg to the finished butterfly, via the caterpillar and pupal stages, often only lasts a few months.
  • Under suitable environmental conditions (e.g. food, heat), many species then have two to three generations per year.
Painted Lady Vanessa cardui
Butterflies react quickly to changes in their environment.
  • In inappropriate areas, they die out quickly because most butterflies are not very mobile. Their radius of action is often only a few kilometres.
  • However, if new suitable areas are accessible to them, they will populate them.

Butterflies have specific requirements to their environment

Some moths, for example, can only live where the Great burnet Sanguisorba officinalis occurs and also certain ants. These are the Large Blues (Phengaris).
Dunkler Wiesenknopf-Ameisenbläuling
Dusky Large Blue
Phengaris nausithous
Heller Wiesenknopf-Ameisenbläuling
Scarce Large Blue
Phengaris teleius

The following video shows the "Large Blues".

"Maculinea" - a movie by Helmholtz Centre of Environmental Research - UFZ (2005). Part 1
"Maculinea" - a movie by Helmholtz Centre of Environmental Research - UFZ (2005).Part 2

Another example: The Small Tortoiseshell

Kleiner Fuchs
Small Tortoiseshell Aglais urticae
This butterfly flies in warm regions in two to three generations per year. It hibernates in sheltered places and can be seen from March or April.
Eier des Kleinen Fuchs
Egg clutches of the Small Tortoiseshell
The female lays about one hundred eggs on the underside of stinging nettles from the end of April.
Raupe des Kleinen Fuchs
Caterpillar of the Small Tortoiseshell
Numerous tiny caterpillars hatch after a few days. In the following weeks, they will go through five larval stages: They will skin four times and become up to 30 millimeters long. The adult caterpillars are dark gray with yellow longitudinal stripes and many branched thorns.
Stinging Nettle Urtica dioica
The caterpillars of the Small Tortoiseshell feed almost exclusively on leaves of the large and small nettles.
Pupae of the Small Tortoiseshell
Pupae of the Small Tortoiseshell
The caterpillars pupate after approximately four weeks. After another two weeks, the new generation of butterflies hatch. The Small Tortoiseshell often hibernates in sheltered places such as cellars or in natural hiding places.
As in many other species, the climate has an impact on reproduction. The warmer it is, the faster is the development. Therefore, Aglais urticae often has three generations per year.
Time scale with generations

Butterfly Monitoring Germany

During butterfly monitoring
Since 2005, volunteer counters have been going to their transects once a week to observe butterflies.
In 2017 there were 331 participants who counted more than 224,000 butterflies from 115 species nationwide.
A total of more than 3 million butterflies have been recorded to date (www.tagfalter-monitoring.de; November 2017).

Of the 53 statistically analyzed species, 21 species showed declines. Particularly clear examples are the the Dark Green Fritillary Argynnis aglaja, the Small Pearl-bordered Fritillary Boloria selene and the Pale Clouded Yellow Colias hyale, but also the Mourning Cloak Nymphalis antiopa and the Large Cabbage White Pieris brassicae. A negative trend was also observed in the Dusky Large Blue P. nausithous.

Population dynamics of P. nausithous. After Kühn et al., 2018
Dusky Large Blue

Of the 53 species analysed, 13 species showed an increase in numbers between 2006 and 2017. The positive trend was particularly marked for the Berger's Clouded Yellow Colias alfacariensis and the Brimstone Gonepteryx rhamni. The Ringlet Aphantopus hyperantus, the Small Heath Coenonympha pamphilus and the Chalkhill Blue Polyommatus coridon also showed a continuous positive development. The Red Admiral Vanessa atalanta also shows an increasing trend (see figure).

Trend_Vanessa atalanta
Population dynamics of V. atalanta. After Kühn et al., 2018
Red Admiral Vanessa atalanta

It is still unclear where the development of the Orange tip is heading.

Population dynamics of A. cardamines. After Kühn et al., 2018
Orange Tip Anthocharis cardamines.
No clear trend can yet be identified for many butterflies from the data collected so far. As with all species, their further development will depend on the environmental conditions in the respective areas.

It becomes obvious that the assessment of the future status of many populations is associated with uncertainty.

How can the questions about future development be answered in view of the uncertainties?

Before we dive into the scientific methodology:

Simulate the impact of climate change on butterflies in Europe.

Here's how you do it:
  • Select a butterfly.
  • Start the simulation.
  • Observe which areas are lost or newly won under each of the assumptions (scenarios).

Butterfly tool

Here you can test how the distribution of species can change
as a result of climate change.
Vanessa atalanta Admiral
Legend: remaining lost potentially new areals

On the development of the butterfly tool

The Brimstone
Gonepteryx rhamni
Verbreitung Zitronenfalter
Records until 1950 Records until 1980 Records also after
Let's start with the Brimstone. The figure on the right shows its distribution in Europe (Status 2000; Kudrna et al., 2011).
Think about why the Brimstone does not occur in northern Scandinavia and hardly occurs in southern Spain. Click on a possible answer.

Unfortunately wrong!


Think again.


Think again.


Right! The climate there is unsuitable. The climate therefore determines decisively where the butterflies live.

Further examples

Cranberry Fritillary
Boloria aquilonaris
Himmelblauer Bläuling
Adonis Blue
Polyommatus belargus
The Cranberry Fritillary prefers cooler regions, while the Adonis Blue lives in warmer areas.
Verbreitung Hochmoor-Perlmutterfalter
Cranberry Fritillary
Verbreitung Himmelblauer Bläuling
Adonis Blue
Records until 1950 Records until 1980 Records also after 1980 (Status 2000; Kudrna et al., 2011)
The climate is changing - how do butterflies react to it?

Not true! The climate influences the habitat. Some species have only a small ability to distribute and cannot reach new areas.


The answer is correct. It depends on their ability to distribute, but also on the landscape structures, whether the butterflies can colonize new areas.


Not true! The climate influences the habitat. Some species have only a small ability to distribute and cannot reach new areas.

But which areas in Europe will still be suitable for the species in the future?

In other words:

Where will there be a suitable climate?

Develop and apply scenarios

To the video

Selin, 14
Szenarios are used to describe "possible futures". Click on the futures.
Szenario Red

Scenario RED assumes that natural resources are exploited to a very large extent; the laws of the market dominate over environmental protection. The mean earth temperature is expected to rise by 4.1°C by 2080.

Szenario Yellow

Scenario YELLOW assumes large regional attempt to protect our resources, but overall environmental protection is insufficient. The mean earth temperature is expected to rise by 3.1°C by 2080.

Szenario Green

Scenario GREEN: Assumption of globally successful efforts towards sustainable development in environment, economy and society. The mean earth temperature would therefore increase by a maximum of 2.4°C by 2080.

The method of

Modelling of climate niches

allows switching from the scenarios to future geographical distributions of butterflies and other species. But what does "Modelling" actually mean?

To the video

Milan, 14

Climatic niche of the Brimstone - greatly simplified

by assuming only two climate factors: temperature and precipitation.
The left figure shows the distribution data of the Brimstone during 1970 to 2000.
Their values are between T1 and T2 or N1 and N2 at all sites. Thus exactly these parameter combinations represent our strongly simplified climatic niche.
The geographical map (left figure; Settele et al., 2008) shows which areas correspond to this hypothetical climatic niche in the year 2030.
Can scientists give a clear answer to the question of the future distribution of a species on the basis of long-term distribution data?

Think again.


Think again.


That is correct. There can be no single, unambiguous answer in view of many uncertainties, e.g. due to climate change.

Simulation for 2080

Where could the Brimstone butterfly occur in 2080? The answers differ depending on the Scenario (Settele et al., 2008). Some areas will no longer be suitable, for example because they become too warm and too dry. The Brimstone butterfly could colonise new areas whose climate is now suitable for it. The prerequisite, however, is that he also reaches these areas and that he finds the required landscape structures and plants there.
Szenario Green
Scenario GREEN
Szenario Yellow
Szenario Red
RED (2080)
Potentially new
Advanced part
Can the methods of scenarios and climate niche modelling be applied to other species?

That is not right. Think again!


Yes, the method can be transferred to other animal and plant species. However, the data must be available for the corresponding climate niches.


That is not right. Think again!


That is not right. Think again!

Other species groups

The Common toad

The Common toad Bufo bufo seems to be quite resistant to climate change, which shows its wide distribution in Europe. However, it could become too hot and too dry even for this toad in many areas.
Common toad Bufo bufo.
remaining lost potentially new
Year 2050 (Scenario RED)
How do trees react to climate change?

That's not right. Choose another answer.


That's not right. Choose another answer.


That's right. Species such as spruce are exposed to great stress due to heat and drought. This makes them easy prey for bark beetles.

Oak and Copper beach

Eiche (Quercus robur)
Quercus robur
Rotbuche (Fagus sylvatica)
Copper beach
Fagus sylvatica
Oak and copper beech react very differently to climate change. Compare the geographical distributions in 2080 assuming scenario RED.

Distribution of Oak (left) and Copper beach in 2080 (Scenario RED)

Verbreitung Eiche
Verbreitung Rotbuche
remaining lost potentially new

What can you do for butterflies?

1. Open your eyes for current problems

Flowering meadow in Magdeburg

Butterflies are an essential link in the vital network of biodiversity. They are inextricably linked to the issues of our time: climate change, changes in land use, loss of biodiversity.

2. Actively addressing the risks for butterflies

Brauner Feuerfalter
Sooty Copper Lycaena tityrus
Scarce Copper Lycaena vigaureae

Use the butterfly tool to identify losers in climate change:

Click here for the Butterfly tool.

3. Plants for the butterflies

For butterflies you can do something in your own garden or even on the balcony. Make your balcony or garden butterfly friendly and offer them nectar.
Nectar plants for butterflies are for example:
  • Thistles
  • Brown Knapweed
  • Stone Crop
  • Autumn Aster
  • Lavender
  • Phlox
  • Sommer Lilac
  • Aubrieta
  • Red Clover
  • Thyme
  • St. John's Wort
Thyme Thymus vulgaris
Sun Flower Helianthus annuus
Red Clover Trifolium pratense

4. Plants for the caterpillars

If you want to protect butterflies, you have to think of the caterpillars!

Many butterfly caterpillars - e.g. Peacock, Red Admiral, Painted Lady and Small Tortoiseshell - feed on the leaves of Stinging Nettles. Cuckoflower, wild carrot and clover are food for the caterpillars of Orange Tip, Swallowtail and Common Blue. Therefore we should also tolerate "weeds" in the garden.
Sting Nettle Urtica dioica
Caterpillars of the Mullein moth Cucullia verbasci


SITAS explains methods that are used in scientific risk analysis.
  • The focus is on the impact of climate change on the habitats of European animals and plants. Butterflies are regarded as an example.
  • In future scenarios, various plausible developments and their effects are described and compared.
  • The climatic niche modelling is based on long-term data on climate conditions and habitats of the respective species.
  • To simplify the description of the climatic niches, four parameters were selected from a large number of climate parameters.
  • For the individual scenarios, the climatic niches, i.e. the appropriate parameter combinations, were projected onto the relevant geographical areas.
  • SITAS shows that large area losses have to be expected for many species, especially for the scenarios YELLOW and RED.
  • We can counter these losses individually, on a local level, for example by offering suitable food plants to the butterflies.


  • Díaz, S., Settele, J., Brondízio, E., Ngo, H. T., Guèze, M., Agard, J., ... Zayas, C. 2019, 29. Mai. Report of the Plenary of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services on the work of its seventh session. Addendum. Summary for policymakers of the global assessment report on biodiversity and ecosystem services of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services​​​​​​​ (Paris, 29 April–4 May 2019).
  • Kudrna, O., Harpke, A., Lux, K., Pennerstorfer, J., Schweiger, O., Settele, J., Wiemers, M. 2011. Distribution atlas of butterflies in Europe. Gesellschaft für Schmetterlingschutz, Halle, Germany, 576 S.
  • Kühn, E., Musche, M., Harpke, A., Wiemers, M., Feldmann, R. Settele, J. 2018. Tagfalter-Monitoring Deutschland - Jahresauswertung 2017. Oedippus 35:5-36.
  • Wiemers, M., Harpke, A., Schweiger, O. & Settele, J. LepiDiv database (Helmholtz Centre for Environmental Research-UFZ & Gesellschaft für Schmetterlingsschutz (GfS) (2015) http://www.ufz.de/lepidiv.
  • Pompe, S., Hanspach, J., Badeck, F., Klotz, S., Thuiller, W., Kühn, I. 2008. Climate and land use change impacts on plant distributions in Germany. Biol. Lett. 4: 564 – 567.
  • Ries, M., Reinhardt, T., Nigmann, U., Balzer, S. 2019. Natur und Landschaft 94(6/7):236-244.
  • Settele, J., Kudrna, O., Harpke, A., Kühn, I., Swaay, C. van, Verovnik, R., Warren, M., Wiemers, M., Hanspach, J., Hickler, T., Kühn, E., Halder, I. van, Veling, K., Vliegenthart, A., Wynhoff, I., & Schweiger, O. 2008. Climatic risk atlas of European butterflies. Biorisk1, 1-710.
  • Settele, J.2019. Bericht: Bestandsentwicklungen und Schutz von Insekten. Analysen und Aussagen des Weltbiodiversitätsrats (IPBES). 2019. Natur und Landschaft 94(6/7):299-303.
  • Spangenberg, J., Bondeau, A., Carter, T., Fronzek, S., Jaeger, J., Jylha, K. Kühn, I...Scenarios for investigating risks to biodiversity. 2012. Global Ecol. Biogeogr. 21: 5–18
  • Ulbrich, K., Schweiger, O., Klotz, S., Settele, J. 2015. Biodiversity impacts of climate change – the PRONAS software as educational tool. Web Ecol., 15, 49–58, 2015.

Photo authors

  • Erk Dallmeyer (p. 37)
  • Darkone/Wikimedia (p. 52)
  • Sabine Flechtmann (p. 22)
  • Wolf-Rüdiger Grosse (p. 50)
  • Günter Hoffmann (p. 54)
  • Manfred Hund (pp. 17,30,34)
  • Elisabeth Kühn (p. 9)
  • Andre Künzelmann/UFZ (pp. 10,12,13,15,24,27,55,56)
  • Kusurija/Wikimedia (p. 52)
  • Michael Linnenbach (S. 50)
  • Hannelore Müller-Scherz (pp. 21,29,34)
  • Joachim Müncheberg (pp. 16,34,35)
  • Josef Pennerstorfer (pp. 34)
  • Josef Settele (pp. 11,18,28)
  • Albert Vliegenthart (pp. 34,54)
  • Daniel Werner (pp. 14,54)
  • Martin Wiemers (pp. 23,25)
  • Andrea Wunderlich (p. 18)
  • Hans-Jürgen Zimmermann (pp. 34,56)