Freshwater Ecology 2/4

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More pictures of this day can be seen on my Flickr page.

Tuesday: Vegetation

It was the Sun, through our big window, that woke me up quite a bit earlier than planned. With the rooms being smaller than last time we took a trip like this, we didn’t sleep in the same one as our teachers. So at least it wasn’t Huub’s Adele alarm that did the trick. During breakfast, Huub tried to explain something about our first assignments: 5, 6, 7 and 4, but eventually concluded it was best if we’d just stick to our syllabus. We did know we’d visit the visitor centre and we’d have a closer look at the plant life in this area, especially ‘krabbenscheer’. Also on the agenda was to investigate how wetlands slowly turn into land (‘verlanding’) and we’d look into the quality of (probably) nutrient rich water. Meanwhile, subgroups had been formed. We all did the same experiments and we would present them to each other and compare in the evening.

The visitor centre sold a lot of nice things, but I managed to not make my bag heavier. Point for improvement (we were asked) was to make it less of a shop and more of an appealing information centre about the area. They did also have a nice garden, with plants that represent the vegetation in the rest of this nature preserve. We learned that the ‘water soldier’ in the pond grows wider at the edges as there’s not enough space to do this in the centre, where they grow more upwards. They have a defence system: sharp edges on their leaves, but a little leaf miner (bladmineerder) eats its way through the plant’s leaf tissue. They can be found in many types of water, but they prefer a ‘clean’ pond. They take up excess nutrients, which is why they used to be used as a fertiliser.

While we had a short break we saw a few swallows probably busy making a nest out of mud and saliva. We also saw mater mint (which smells more like anise), gele plomp, waterviolier, zonnedauw, traces of a gall wasp and we heard a tureluur. To name a few of the species we had to memorise as characteristic for this region. During our walk, we stopped at four places to investigate the change of the land; how it gradually becomes less wet and how this leads to a change of vegetation. We stopped at a ‘petgat’, near ‘trilveen’ (where we saw the fallen mill), at a ‘legakker’ (next to a little bridge) and at the edge of a ‘moerasbos’. We described the local plant life and tested the water’s temperature, its pH, depth and transparency (with a Secchi disk).

As expected, windward and leeward direction has an effect on the vegetation. We also learned that the gradual changing of land is mostly due to reed, which grows from the sides of the water and often forms little (floating) islands called ‘kraggen’. Of course, the influence of humans also plays a role, as they made dams of these islands. Nowadays we try to keep the wetlands though, because of their importance for the biodiversity. When looking at the plant life in these different stages of land, you often see different plants as well as ones that seem to grow everywhere. As expected, you can see the change in vegetation gradually too. (This was the conclusion of our presentation that evening).

Besides what had to be seen according to our plan, we also had a few nice surprises. Near the legakker, we clearly saw a big root of the ‘lisdodde’ on the water. And we saw a ‘ringslang’ lying on a leaf in the water! An unpleasant surprise where the biting midges (‘knutjes’). They suddenly fly around you in groups, which is very annoying as it is, but even though their size makes them seem harmless, they are not! Even when you’re wearing a hoodie, they will find spots of skin, in your face, to bite in and leave an itching mark (I found them worse than ‘normal’ mosquito bites). And on top of this, they don’t seem to be bothered by the otherwise good working mosquito repellents. The only option seemed smoking (or in my case: standing next to someone who smokes) or hiding from them.

But it didn’t spoil our fun. All that water today had been very inviting. When we were back home I couldn’t be stopped anymore and found a place in the lake to jump in. On twitter I summed up my day in 140 characters as: 1. Worked hard in the Sunshine 2. Took a dive in the lake 3. First round of presentations went well. 4. … The dot-dot-dot stood for listening to the Beatles (Here Comes The Sun) together, drinking whisky (note I still have never been drunk in my life) and I ended up explaining why I know so much about stars and planets and certain Voorwerps in the sky. Meanwhile, Wichard had left notes on the wall with compliments for every subgroup. We liked this. It was a good day. And tomorrow would involve boats, which always makes everything even better.

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