Geography students did their field work at the spectacular dune fields in Soest
In order to practice some essential Geographical field skills the DP1 Geography students traveled to a nearby dune field, the Soest Duinen in Soest (province of Utrecht). The Soest Duinen are composed of two massive dune fields, the Lange Duinen and the Korte Duinen both located in the middle of the forest in Soest, 17 km away from the city of Utrecht.
By Amaya Menendez, geography teacher
It was lovely to finally be able to take the students on a much needed trip so they could practice their field work skills. The students were required to undertake a number of measurements in groups at the study area so that you could answer their research question and formulate hypotheses.
Possible Research Questions
To what extent does the forest dune succession conform to the typical Psammosere coastal dune development?
To what extent is there a prevailing wind direction affecting the dunes geometry at the dune field?
Measurements the students needed to take:
Sediment size transect; sediment size can tell us about the energy of the waves and/or wind and explain the sand dune profile. Sand and pebbles can be ordered in size up a dune field due to the stronger winds bringing heavier material up, but the weaker winds being able to only bring back the lighter material due to less energy.
Infiltration rate transect; how quickly water percolates through the dunes can give us information about its sorting (how similar are the sediment particles sizes to each other) and/or the presence of developed soil along the dune transect.
Dune transect; For this section you are going to complete 2 transects from the base of one given dune until the back of the next dune.
Count the number of species and heights present in a quadrat or height of tallest tree using clinometer and trigonometry
Collect soil samples at transect interval to calculate soil, water and organic content (later in lab); Soil is collected using a small spade to the same depth at each site (10 cms), this soil is then bagged and labeled for testing in the lab.
Testing pH Using Soil Strips; Changes in the pH of the soil can help us identify if there is a natural dune succession, such in a coastal dune field (pH becomes more acidic as we move away from the sea in coastal dunes)
The Long Dunes, as well as the nearby Short Dunes, are a geological monument of the Netherlands. The stretch of sand offers a rare, important glimpse of the region’s natural environment and the geological processes that shape it. The sands were pushed south during the advance of the last ice age, and they’ve remained here since, though the wind continues to influence the area. (atlasobscura.com).
The mass of sand at the dune fields is encircled by woodland, and there are unique trees scattered within the dune as well. Here, you’ll find some trees with “floating” roots. Though it looks like the trees are climbing out from the sand to take their own walk throughout the park, their exposed roots are actually a result of wind erosion.
So what did the students think?
‘The study area we visited for our practice IA is the Soest Duinen; a large nature reserve in the Soest province which consists of a range of sand dunes and stretches of forest. The Soest Duinen is separated into the ‘Lange Duinen’ and ‘Korte Duinen’ where picnic enthusiasts and dog walkers come to spend their afternoons. The reason for this fieldtrip was to practice our geography data taking skills such as infiltration, elevation, wind speeds and species diversity. All of these are very hand-on skills which will be used in the rest of our IB Geography career.’ – Imogen, Peter & Jason
Methods: infiltration rates and sediment size Sand gets blown into dune valleys — heavier, bigger sand grains are too heavy to be pushed/lifted back up the hill, where the finer grains lie. We care because finer grains of sand allow for more biodiversity opportunity. We took these measurements by holding up an anemometer at intervals of 10 meters. – Jesper, Lucy & Anton
Method: dune transect (Measurement of gradient and distance from the top of one dune to back of next dune. — ‘To see the what the past of dunes can tells from the present that it is presented to us, thus this makes us think about the consequences of a dune being in the wilds. The dunes have been influenced by numerus factors. It is very important for the development of mankind, knowing the current state of the dunes we can predict how this area will look in the future – how it will change. We used some tools like an anemometer to see the movement of the wind. The first person stood with a distance measuring pole, one end of a measuring tape, and a clinometer. Another person would walk up the dune with the pole, unrolling the measuring tape. This person continued walking until the slope changed, where they would stop and record the distance travelled.’ – Merijn, Julka, Ana & Hassan
Method: wind velocity and species diversity —‘Wind velocity is important to consider because it determines where and how far sand is distributed, affecting the size of dune. Using an anemometer, it can be raised into the air. The wind will cause the four cups to spin, lifting the band they are attached to up to align with a number on the handle. That number is the wind speed. Species diversity is important because the existence of organic life can determine and affect the placement and distribution of the dunes. Using a metal frame, we placed it down and counted all the different species we could find visible to the naked eye. After doing this multiple times we could determine average species diversity.’ – Samantha D, Samantha L. & Tara
