"Three out of four people want a mixture of open and untouched forest for rambling. At the same time, we can see that birds do well and continue to nest in woodlands where less than 50% has been cleared", says Erik Heyman of the Department of Plant and Environmental Sciences at the University of Gothenburg.
The natural environment close to urban areas is becoming evermore important as more people choose to live in cities. Biological diversity is relatively high in Swedish urban woodlands, while these areas are important also for recreation and outdoor activities. The woodlands must be managed correctly, in order to preserve their ecological and social values.
Erik Heyman's studies are based on large-scale field experiments in five deciduous forest areas close to three midsize cities in south-western Sweden: Alingsås, Borås and Skövde. Two different types of clearance were carried out: a 90% clearance of the understory, and a 50% clearance that was carried out in a grid pattern of squares of size approximately 50 x 50 m. The two types of clearance were carried out over an area of 3-5 hectares, and areas of corresponding size were left undisturbed in each forest area as control areas.
"The number of nesting birds fell in the areas of 90% clearance, while the 50% clearance did not have any detrimental effect on the number of birds. Predation by birds had a large effect on arthropods in the understory, and this means that an important food resource for insect-eating birds is removed when the understory is cleared."
The recreational value of the forest has also been investigated by Erik Heyman in two types of experiment. In the first, photographs of the cleared forests were shown to experimental subjects, who were then asked to assess them. In the second, cameras were given to subjects, who were then asked to photograph liked and disliked places along a rambling path through the woodlands.
"Analysis of the photographs showed that both open and dense forests were appreciated, while visible traces of humans impact such as litter and evidence of clearance activity were perceived negatively. Clearance of understory and small trees can increase the recreational value of the woodlands but it should be carried out in small areas in order to create variation and avoid detrimental impact on birdlife. Forest management, permanent signposts, rubbish bins, benches, etc., should be designed to blend into the forest as far as possible.
The thesis was successfully defended on May 27, 2011.Bibliographic data
Journal: BMC Ecology 11, 8
Microjet generator for highly viscous fluids
13.02.2018 | Tokyo University of Agriculture and Technology
Sweet route to greater yields
08.02.2018 | Rothamsted Research
A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.
In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...
A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.
By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...
Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
23.02.2018 | Physics and Astronomy
23.02.2018 | Health and Medicine
23.02.2018 | Physics and Astronomy