A good 50% of Germany’s land – about 18 million hectares – is used for agriculture. This land is subject to rhythms of plowing, sowing, harvesting, and grazing. The fields and pastures are home to both wild animals and plants. How certain organisms adapt to dynamic landscapes, what consequences this has for biodiversity and how changing patterns of movement impinge on mechanisms of coexistence and competition are all being examined by biologists in the DFG Research Training Group BioMove, which started last October.
“It is the wedding of two research disciplines,” says biologist Niels Blaum with a wink. BioMove links two fields of research. It is a joint project of the University of Potsdam, Freie Universität Berlin, the Leibniz Institute for Zoo and Wildlife Research (IZW) and the Leibniz Centre for Agricultural Landscape Research (ZALF). While biodiversity research dedicates itself to all aspects of biological diversity, movement ecology asks why, how, and to where organisms move. Between these two disciplines there are overlaps.
Movement influences biodiversity – and vice versa
“In order to stop the advancing loss of our biodiversity, we first and foremost need to better understand how diverse species can coexist at all,” explains Florian Jeltsch, Professor of Plant Ecology and Conservation Biology and BioMoves’ speaker. “The ability of organisms to adapt to environmental change by modifying their movement patterns plays an important but overlooked role.” Agricultural landscapes – with their constantly changing conditions – offer an ideal framework to more precisely analyze the connections between individual movement and changes to biodiversity, Jeltsch explains. “This approach is ultimately a step towards an ‘individual-based’ ecology, comparable to the transition from classical physics to particle physics.”
”An agrarian landscape is one of the most dynamic landscapes; it experiences extreme changes on a large scale within one year,” says Niels Blaum. Plowing, sowing, fertilizing, harvesting – in the span of a year, the soil and vegetation of cultivated fields change massively. For ecologists and biodiversity researchers, this landscape is an optimal model system to observe how organisms’ movement patterns and biodiversity influence each other. The spatial and temporal dimensions of movement determine where certain species compete for food and living space as well as where they can coexist. To examine these complex interactions, researchers from the ZALF and the University of Potsdam developed the idea of AgroScapeLabs. These agrarian landscape laboratories enable experimental research at the level of the landscape – a godsend for every ecologist and biodiversity researcher.
In northeast Brandenburg – in the gathering ground of the creek Quillow – sits the group’s 291-km² research area. A mosaic of larger and smaller fields, woods, and small ponds offers optimal conditions for the ongoing research projects.
A total of 12 young researchers will complete their doctoral studies as part of the research training group. In their projects, they examine how individual movement patterns and complex biodiversity patterns interconnect and how the landscape determines diversity at the genetic level of certain species. The spectrum of methods is, therefore, diverse. In addition to on-site observation, mapping, and open-air experiments, the young scientists will also do their research with the help of computer models. “The spread of wild disease, for example, depends on how animals move,” Jeltsch explains. “This can be simulated with mathematical models.”
Technical advances allow deeper insight
Biologist Wiebke Ullmann’s doctoral project focuses on the hare. In order to research its movements, the young scientist outfitted previously captured hares with GPS-integrated collars. “What do the animals do before the harvest; what do they do after it; how do they move within a year?” She is pursuing these questions with the help of recorded movement patterns. She has already outfitted 36 animals with these transmitters.
Niels Blaum pulls up an image on his laptop – a satellite image of the research field. Blue lines running across the field indicate many days of GPS data from a wired hare. Its movements follow a certain pattern: It sticks to fixed paths and uses only a small part of the field. Four days later, however, the movement pattern has changed completely. The hare suddenly moved to areas that it had previously avoided. What happened? “There used to be an alfalfa field here that was mowed down,” reports Blaum. “When the plants are tall, the hares can no longer survey the landscape,” explains Ullmann. They avoid areas where their sight is limited, so that foxes are not able to sneak up on them. As soon as an area has been harvested and their sight is free again, they retake the areas they had previously avoided.
To be able to evaluate the information, Ullmann needs not only the movement data of the wired hares. She also has to know what is happening in the surroundings, which fruits are being planted in the fields, and how tall the plants are in a particular season. Once a month, she drives to the research area to measure plant height and evaluate the transmitter data using special geo-information software. This allows her to investigate how plant height, for example, affects the hares’ movement patterns.
”Telemetry technology has rapidly developed over the past five years,” explains Blaum. The research profits from this not only through lighter and smaller transmitters or longer battery life. Especially valuable is the information that the transmitters send in addition to the spatial data. The so-called acceleration data – measured in four-minute intervals – shows the animal’s behavior. This allows the researchers to see if the animal slept, ate, or was on the run. This offers an enormous increase in knowledge, stresses Wiebke Ullmann. “With the data, we can even calculate how much energy the hare expended.” New technological means enable the researchers to move well beyond simple localization studies. Effects from – human-caused – disruptions become as recognizable as the small-scale behavior of hare.
In order to calibrate the system, the researchers initially observed the wired hares under controlled conditions in enclosures and outdoors. Which signals indicate an eating hare? Which ones indicate a fleeing hare? The researchers based the patterns on the corresponding behavior and can now say what is happening based on certain signals. “Using statistical analysis, we can even use this information to assign patterns for which we have no observations,” explains Blaum. “This gives us an unbelievable added value of information.”
Where the hare stops is also important for other organisms – and here is where movement ecology and biodiversity research merges. The brown hare carries plant seeds on its fur and in its feces, resulting in dispersal. The researchers have found up to 20 plant varieties in hare feces, which they allowed to germinate in the greenhouse. “During the course of the agricultural year, the hare is limited and can only do this at certain points in time,” explains Ullmann. The researchers will be analyzing which vegetation is growing in the district of the wired hares and what role they play in the dispersal of certain species.
The landscape laboratory
The hare is only one of many organisms that the young researchers in BioMove are examining. Bats, storks, mushrooms, and even yeast of flowering plants are objects of their further comprehensive research projects. Biologist Guntram Weithoff and his doctoral student Pierluigi Colangeli are interested in, for example, microscopic water organisms that live in the numerous kettle holes of the landscape laboratory. Rotifers, water fleas, and ciliates – life is surprisingly diverse (with about 100 varieties of zooplankton) in the small, water-filled depressions, some of which repeatedly dry out over the course the year. The researchers want to find out how many varieties are dispersed by the wind and how effectively they can settle in new living spaces.
For this purpose, the researchers have installed “windsocks” in the field – pointy nets made of fine-meshed gauze. The biologists use these nets to hunt for specific life phases of the zooplankton – the “dormant stages”. These organisms are able to withstand adverse conditions like longer dry spells in well-protected capsules or “dauer larvae” that are about 50 µm large. “We assume that the organisms in dried-out kettle holes are very effective at dispersing themselves through the wind,” explains Weithoff.
Once a month, the researchers will measure what they captured in their nets. Under the microscope and with the help of genetic analysis, they can determine which species are especially good at traveling with the wind. Whether they also successfully colonize new living spaces is another question that the researchers want to examine using artificial kettle holes. Around 30 water containers will be set up and the colonizing of water organisms in them will be regularly checked. “We will then be able to determine the rates of success and which species are especially successful at colonizing new habitats,” says Weithoff. The researchers are planning further lab investigations, in which they will cultivate plankton organisms from the kettle holes under controlled conditions in a culture medium to determine under which conditions certain species prevail.
Wired hares, nets in the wind, artificial water basins, wild plants in flower pots, or pollen-collecting researchers – research at AgroScapeLab Quillow will become especially visible in the coming months and years. Thanks to “the landscape laboratory”, the researchers are not only able to realize their research on a grand scale but are also addressing an important question for the future: how can cultivated land contribute to protecting biodiversity? “The fact is, we don’t have much land left that we can protect through conservation,” explains Niels Blaum. “In the future, we will have to think about how to optimally manage unprotected land in order to maintain biodiversity.”
The Project
The BioMove Research Training Group researches the effect of movement ecology in dynamic agricultural landscapes on biodiversity.
Participating: University of Potsdam, Freie Universität Berlin, Leibniz Institute for Zoo and Wildlife Research, and Leibniz Center for Agricultural Landscape Research
Funding: German Research Association (DFG)
Duration: 2015 - 2020
www.biomove.org
The Researchers
Prof. Florian Jeltsch studied physics and theoretical ecology in Marburg. Since 2000, he has been Professor for Plant Ecology and Nature Conversation at the University of Potsdam. He is spokesperson of the BioMove Research Training Group.
Universität Potsdam
Institut für Biologie und Biochemie
Am Mühlenberg 3
14476 Potsdam
Email: jeltschuuni-potsdampde
PD Dr. Niels Blaum studied biology in Frankfurt/Main and animal physiology in Nice (France). Since 2001, he has researched at the University of Potsdam investigating the influence of land use on biodiversity.
Email: blaumuuni-potsdampde
Dr. Guntram Weithoff studied biology in Berlin. He has been a research assistant at the Institute of Biology and Biochemistry since 2000. His research interests are biological invasions and biodiversity of plankton organisms.
Email: weithoffuuni-potsdampde
Wiebke Ullmann studied biology at Humboldt Universität zu Berlin and ecology at the University of Bremen. Since 2013 she has been researching the movement behavior of hares in dynamic agricultural landscapes at the University of Potsdam and the Leibniz Center for Agricultural Landscape Research.
Email: wiebke.ullmannuuni-potsdampde
Pierluigi Colangeli studied biology in Bologna and Brussels. Since 2016 he has been a PhD student in the working group Ecology and Ecosystem Modelling.
Email: colangeluuni-potsdampde
This research is linked to the research initiative NEXUS: Earth Surface Dynamics, which clusters approaches from various scientific disciplines in the Berlin-Brandenburg area within the overarching theme of Earth surface dynamics. The University of Potsdam, along with its partnering institutions the Helmholtz-Centre Potsdam - German Research Centre for Geosciences (GFZ), the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI) and partners from the Potsdam Institute for Climate Impact Research (PIK), the Museum für Naturkunde - Leibniz Institute for Evolution and Biodiversity Science (MfN) and the Technische Universität Berlin (TUB) therefore combines the outstanding expertise from geo-, bio-, climate and data sciences.
Text: Heike Kampe
Translation: Susanne Voigt
Published online by: Agnetha Lang
Contact for the editorial office: onlineredaktionuunipotsdampde