biology

Johannes Iversen

Johannes Iversen is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Johannes Iversen rather than just read about it. In short: Johannes Iversen (Danish pronunciation: [ˈiˀvɐsn̩], 12 December 1904 – 17 October 1971) was a Danish palaeoecologist and plant ecologist. Biography He was born in Sønderborg and began studies in botany at the University of Copenhagen in 1923 under professor C.H.

Key takeaways

Johannes Iversen belongs to biology; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Johannes Iversen to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Johannes Iversen from memory before moving on to harder problems.

Reference excerpt

Johannes Iversen (Danish pronunciation: [ˈiˀvɐsn̩], 12 December 1904 – 17 October 1971) was a Danish palaeoecologist and plant ecologist.

Biography He was born in Sønderborg and began studies in botany at the University of Copenhagen in 1923 under professor C.H. Ostenfeld, and with considerable inspiration from prof.em. Christen C. Raunkiær. At first he worked with macrophyte vegetation of lakes in relation to water pH. The influence from Raunkiær is particularly evident in Iversen's doctoral thesis, in which he divided herbaceous plants into hydrotypes based on experiments and morphological studies: xerophytes, mesophytes, hygrophytes, telmatophytes, amphiphytes and limnophytes. In addition, halobio-types (salt tolerance) were described. He brilliantly used modern equivalents in the interpretation of pollen diagrams, e.g. his now classic studies on frost damage to ivy (Hedera) and holly (Ilex) during the severe winters of the early 1940s led to their fossil pollen being used as climate indicators. Iversen demonstrated the steppe and tundra components of the late glacial flora. Iversen conducted a practical experiment with stone axe clear-cutting and slash-and-burn agriculture in a primeval forest to study the forest regeneration. In 1931, Iversen was first appointed assistant at the Geological Survey of Denmark and Greenland. In 1938, Iversen became a Sectional geologist and in 1942 he became State Geologist, an appointment he kept until his death. In 1955, he became a lecturer in pollen analysis at the University of Copenhagen. In 1953, he was made a member of the Royal Danish Academy of Sciences and Letters. He was awarded honorary doctorates at Uppsala University and Cambridge University.

Textbook of modern pollen analysis Fægri, Knut & Iversen, J. (1950) Textbook of modern pollen analysis. Ejnar Munksgaard, Copenhagen. 168 p. Fægri, Knut & Iversen, J. (1964) Textbook of pollen analysis, 2nd edn. Scandinavian University Books, Copenhagen. 237 p. Fægri, K. & Iversen, J. (1975) Textbook of pollen analysis, 3rd ed. by Knut Fægri, Scandinavian University Books, Copenhagen. 294 p. Fægri, K. & Iversen, J. (1989) Textbook of pollen analysis. 4th ed. by K. Fægri, P.E. Kaland & K. Krzywinski. John Wiley & Sons, Chichester. 328 p.

… excerpt ends here. Continue reading the full article.

Illustrations

Worked examples

Example 1 — a first encounter with Johannes Iversen

Start with the simplest possible case. Write down what Johannes Iversen claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Johannes Iversen before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Johannes Iversen ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Johannes Iversen

In research: Johannes Iversen appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Johannes Iversen in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Johannes Iversen is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1904 births, 1971 deaths, 20th-century Danish botanists, so understanding it makes those chapters shorter.
In everyday life: Look for Johannes Iversen outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Johannes Iversen in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Johannes Iversen means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Johannes Iversen out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Johannes Iversen in simple terms?

Johannes Iversen (Danish pronunciation: [ˈiˀvɐsn̩], 12 December 1904 – 17 October 1971) was a Danish palaeoecologist and plant ecologist. Biography He was born in Sønderborg and began studies in botany at the University of Copenhagen in 1923 under professor C.H.

Why does Johannes Iversen matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Johannes Iversen?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Johannes Iversen.