What is plant physiology and ecology

This booklet focuses on the term "ecology" and explains what ecological research is about. The principles of evolution and coevolution are explained and the importance of ecosystems is revealed. The final subject area is nature conservation and security research.

 

What is ecology

Nobody lives for himself alone

The term "ecology" comes from the Greek (oikos = house community) and originally describes the doctrine of the interrelationships between organisms and their animate (biotic) and inanimate (abiotic) environment. The term was coined almost 150 years ago by the developmental biologist Ernst Haeckel. Haeckel understood ecology to be a largely descriptive doctrine of the adaptations of an organism to the environment.

 

What is ecological research about?

Who, what, when, where and with whom?

The aim of ecological research is to understand the relationships between living beings and their environment, to develop models that enable a prediction of changes, or to derive regularities from the observed systems.

Ecological issues arise on three different levels:

1. Interactions between living beings and environmental factors such as food, light, temperature

2. Relationships between the living beings of a species (e.g. increase or decrease in the number of living beings within a species depending on location factors) or between different species (e.g. predator-prey relationships)

3. Relationships of entire communities to their environment (e.g. material flows and cycles) or in other words: studies of ecosystems.

Ecology works interdisciplinary, e.g. with climatologists, geologists or systematists. As the chapters on Darwin and Mendel will show, evolutionary biology and genetics are important disciplines in ecology.

In addition to the classic methods, such as determining location factors and species composition or describing interactions, genetic engineering methods have also found their way into ecological research. For example, genetic analyzes are used to examine relationships between organisms and their developmental development, or genetic modifications are carried out to understand the function of genes.

Ecological research using genetic engineering:

For example, genetically modified plants are used to examine the ability of plants to repel pests in more detail:

Plants with the potential "insect repellant gene" switched off can be released for experimental purposes under strict conditions. If the "defense against enemies" is actually switched off, the plants are more strongly attacked by pests. The responsible gene has been identified and its functionality can now be examined in more detail.

 

What is an ecosystem?

Living communities of nature

An ecosystem is a system that includes all living beings (biocenoses) and their inanimate environment - the habitat (biotope) - in their interrelationships.

Ecosystems can be very diverse, from the deep sea to the highest mountain peaks, from the tropical rainforest to agricultural areas. They can have arisen naturally or through human influence. Their extent varies and it is often difficult to differentiate between different ecosystems. As the examples of the deep sea and mountain peaks show, there are very different ecosystems that are populated by very different living beings or by different types of the same species, depending on the respective environmental factors same kind?

 

Why are there so many animal and plant species?

Darwin's theory of evolution

The term evolution comes from the Latin (evolvere = unwind, develop) and means development. The question of the descent of species from one another and the development of new species is dealt with in the theory of evolution. This branch of biology, founded by Charles Darwin in the mid-19th century, represents the scientific approach to explain the formation and change of living things in the course of the earth's history.

The basis for the emergence of species diversity (biodiversity) is that the descendants of living beings can have different properties than their parents. The new properties can be more favorable for survival or also disadvantageous - every "new type" has to prove itself in nature. Environmental influences such as climate, light and soil conditions, enemies or the density of individuals are (selection) factors that affect the living beings in a location. The development of all living beings takes place according to the principle of natural selection: it inevitably takes place without a previously planned goal. At first it happens to produce individuals who are better adapted to the environment. The more adapted a living being is to its environment, or the faster it can adapt to changing conditions, the greater its chances of asserting itself against other individuals

to pass on one's own genetic material to the offspring and thus to increase it ("Darwinian Fitness"). Over the course of many generations, this process leads to a significant change in the genetic make-up within the individuals of a species (ecotype; natural variations) up to the emergence of a new species.

Species that can quickly adapt to changing environmental influences have an advantage over those that cannot. This ultimately leads to a species shift at the respective location. In the end, this interplay of different animal and plant species is the basis for the diversity of species in a given place.

Moth in England, a classic example of natural selection:

Originally, the moths were well protected from birds by their light-spotted wings on the light-colored birch trunks. The air pollution during industrialization made the tree trunks darker. Moths that happened to be darker in color have since been camouflaged better than lighter ones. They were therefore able to multiply more intensely and pass the dark color on to their offspring. An adaptation to changed environmental conditions took place through natural selection.

What do Darwin and Mendel have to do with each other?

Evolution and genetics

Darwin assumed inheritance of traits but did not know what it was based on. He could interpret the extinction of uncompetitive species and the selection of useful adaptations, but not the emergence of new species or the formation of new adaptations. Gregor Mendel provided one of the missing pieces of the puzzle to understand the origin of species and the mechanisms of adaptation through his targeted crossbreeding of peas. In his experiments, he was able to prove, on the one hand, that properties are passed on to the next generation according to certain regularities (Mendel's rules).

On the other hand, his experiments also showed that the offspring from a cross have the characteristics of the parents in a mixture with different degrees of expression. So children can have different characteristics than their parents (Ask the Grape, Part 1). This is of great importance for the emergence of new species or better adaptation to a location.

Some of the children's new combinations of properties turn out to be more favorable for survival on site than others and thus increase Darwinian fitness. Since Mendel, the puzzle of understanding heredity and species formation has been more and more completed. Molecular biological studies finally revealed that offspring not only have the characteristics of their parents in a new combination, but that they can even have completely new characteristics. This is based on mechanisms that take place at the level of chromosomes and genes (Ask the Grape, Part 1).

 

What does coevolution mean?

After the game is before the game

Coevolution is understood as the mutual influence of the development of two species. In addition to environmental factors such as light, temperature or nutrients that determine the conservation or occurrence of a species, the relationships and communication between the existing organisms also play a decisive role in the biodiversity of a site.

An example of these adaptations and counter-adaptations can be found in wild tobacco (Nicotiana attenuata): Usually this poisoned his enemies with nicotine. However, some caterpillars have now succeeded in developing a defense mechanism against the poison. It is also said that they have developed a tolerance to nicotine. As a result, wild tobacco produced a new strategy to repel such caterpillars. It uses specially formed fragrances to summon the natural enemies of these caterpillars, for example parasitic wasps, and even produces substances in its leaves that "hit the pests' stomach" by disrupting their digestion.

Coevolution ensures that the balance of power between organisms keeps changing.

 

How do ecosystems behave?

Good times Bad Times

Ecosystems appear stable, but are not viewed in geological time frames. Following the mechanisms of evolution and coevolution, the species composition changes constantly - from microorganisms (fungi, bacteria) in the soil to mammals or trees. All living beings in a biotope are just as dependent on its abiotic nature (light, temperature, minerals) as on their "contemporaries" with whom they are in one location. The so-called "ecological balance" is dynamic and not static. Changing just one factor - be it biotic or abiotic - can lead to changes in the entire ecosystem.

There are natural factors that change existing ecosystems very abruptly and in the short term. Forest or steppe fires caused by lightning strikes, for example, allow the entire development of the site to run again, whereby some organisms have adapted so well to the recurring fires that they use them to their advantage. The immigration of new species can completely transform an ecosystem. The "old established" species can be displaced, for example, if the new species is an enemy for the existing species or if the immigrant species is very competitive.

People are - among many others - a factor that influences the development of a location.

 

Ecological = natural = good?

The change in the concept of ecology

Rapid developments in production technology and changes in the industrial and agricultural sector led, on the one hand, to an increase in prosperity in Germany and all of Europe after the Second World War. On the other hand, these processes affected the environment. Air, water and soil pollution were the result. It was necessary to counteract this.

Favored by increasing prosperity, sufficient food production or overproduction and a low unemployment rate, the focus was increasingly on these negative consequences. The concept of ecology, once coined by Haeckel, underwent a change: since the 1960s and 70s, it has no longer been generally referred to the interrelationships between living beings and the environment, but has been used primarily for the relationship between humans and the environment. It was important to protect the environment and nature from the negative consequences of human activity. The word ecology was henceforth used in connection with environmental or nature protection or as a synonym for untouched, natural or perfection; Ecologically used in the sense of environmentally friendly, clean, considerate or healthy.

Largely spared natural disasters, epidemics and hunger, nature is now viewed in its entirety as positive - at least in the western world.

 

Two terms for the same thing?

Ecology and nature conservation

In addition to basic ecological research, which deals with the structure of relationships between organisms and their environment, applied ecology plays an important role. It tries to apply the knowledge about the relationships between the environment and organisms to practical questions of nature and species protection.

For example, before a major change in use of an area is approved, expert opinions must be drawn up. They describe, determine and evaluate the effects the respective project will have on people, animals, plants, soil, water, air, climate and agriculture as well as cultural and material assets. Interactions between various factors are just as much a subject of such reports as measures to avoid, reduce and compensate for the effects that have been determined.

 

What does accompanying research mean and what results has it brought?

25 years of research show that genetically modified plants do not pose a specific risk

The aim of the accompanying or safety research was to investigate the relationships between genetically modified plants and their environment. To this end, objections and fears that were raised in the public debate about green genetic engineering were taken up in the research projects. The Federal Ministry of Education and Research has financed more than 300 projects on biological safety research with more than 100 million euros since 1987. The resulting scientific publications came to the conclusion that the genetically modified organisms previously brought into the wild are not associated with any genetic engineering-specific risks.

The results of the BMBF-funded security research are also confirmed by research work by the EU and neighboring European countries. The Swiss National Research Program (NRP59) "Benefits and Risks of the Release of Genetically Modified Plants", which was financed with 12 million Swiss francs over 5 years, also came to the conclusion in its final report 2012 that there are no specific health or environmental risks for the Greens Genetic engineering could be determined. A result that is also in line with over 1000 studies that were carried out worldwide and evaluated within the framework of NRP59.

Overall, the summary of the results of the safety research funded by the EU with EUR 300 million over 25 years has been available since 2014, which also comes to the conclusion that genetic engineering does not pose any greater risks than conventional methods of plant breeding. Unfortunately, the findings of security research are hardly reflected in social debates or in political decision-making processes. Research on and with genetically modified plants or their use in agriculture takes place in the field of tension between science, society and politics, with the scientific basis increasingly taking a backseat in favor of more and more political discussion and socio-political decision-making.