Field Work At Ainsdale National Nature Reserve

Introduction

The Ainsdale dunes are typical of most dune systems, in that they have high dune ridges and dune valleys containing slacks. Slacks are formed when a blowout occurs, and the wind carries all the sand out of a dune valley, until the ground level is below the sea water, this lets fresh water form in these blowouts and they become slacks.

During the summer the damp slacks are home to a variety of flowers. Such Flowers include; Marsh Helleborine, Early-March Orchid, Round-leaved Winter-green and Grass of Parnassus.

Succession is the increasing amount of biomass, in a particular area, so that more species of life can be supported on that same area. So in the sand dunes, at first there is only sand, next there is the strand line, where the conditions are hardly admirable. The conditions are windy, cold, salty and the soil/sand lacks in nutrients. The first plants to live in this area must be very tough indeed, these type of plants are called pioneer species.

Once these pioneer plants have died, there will be a layer of dead biomass left over, which will be rich in nutrients. This will soon become soil, and more plants will be able to grow in this area, as the sand dunes move in, the winds drop and there is less salt. Since as the dunes move further in, the conditions are more admirable, a wider variety of plants will be able to grow, when these plants die, more plants are left over, and therefore there is more soil, and therefore the process starts again.

There are several stages in sand dune development, each stage will reflect the ability the dune has to support life, they include;

Embryo Dune
	-Generally small.
	-Only supporting Sand Couch and Lyme Grass

Mobile Dunes
	-With the dead sand couch and Lyme grass, there is more soil therefore more chance for nutrients to be absorbed.
	-This type of dune supports Sea Holly and Sea Spurge.

Semi-Fixed Dunes
	-Restharrow, Sand Sedge and Birds Foot Trefoil live here.
	-Land is more stable, and patches of Marram are increasingly sparse.

Fixed Dunes
	-Although conditions are far better than that at the strand line, conditions are still unfavourable. Nutrients are in short supply, and the ground is not incredibly stable. The pH is still very high and there is a possibility of drought.

Method

To find percentage cover of all plants at different areas of the sand dune, to examine their development due to successions, we used a quadrat, and worked out the percentage cover of each plant in each metre squared. Our first quadrat was placed at the strand line, then we worked in 20m stretches, placed the quadrat down for every 20m we walked. The quadrat was placed, and the percentage cover for that quarter was calculated, then we flipped the quadrat another 3 time, to form a square, calculating the percentage cover of each plant.

Every 60m we took a soil sample with a trusty spoon. Which was then  later used to check the pH of the soil at that specific point. The pH was checked by adding a spatula full of barium sulphate to the soil, and then diluting this mixture. Universal indicator was then added, and the pH was calculated.

The temperature of the environment was also taken every 20m, this was done by holding a thermometer in the air for 30s, then taking the reading, this would help show the temperatures that the plants had to deal with, caused by the strong cold sea winds.

The elevation and dissention of the dunes was also recorded, from one 20m reading to the next. This was done using an glinometer, it measured the angle in degrees from one area to the next. With this and the knowledge that each reading was 20m between each other, we can calculated the height of the dune.

And an instrument was also used to measure the amount of light in a certain area. Each time we laid this device on the ground, and took the reading. This shows how much light the plants are receiving at ground level to be able to photosynthesise.

Conclusions

The second you get onto the dunes, you notice the wind, then you notice the dry sand hitting you in the face, then you notice the cold dry sand hitting you in the face bacause of the wind. Basically it aint too good to do a scientific experiment, so by that logic it cant be too easy to live there. The plants that live in this area are very tough indeed, they have to put up with the most awfull conditions.

In scientific terms, the wind will increase the rate of transperation, because since the water vapour leaving the plant is instantly taken away by the wind, maintaining the concentration gradient for water to leave the plants. The air and ground is also very salty, this means that the waterpotiential in the soil is very negetive and the plants will lose water through their roots also. The plants that live on the dunes have adapted to cope with these conditions.

The results gained (see kyte diagrams), show that succession has taken place, because as we go further and further into the dunes, there is a wider variety of plants to be seen, this shows that as more soil accumulates, more life can be supported. It is also notable that couch grass is emidiatly wiped out as soon as marram grass starts to grow, this shows that marram grass is far superior at absorbing nutrients and retaining water, as opposed to couch grass.

pH dropped has we went further into the dune, this would have been caused by the lack of salt from the sea reaching so far in land. In other words, the extreme coast was only alkaline because of the heavy precence of salt from the sea, once the salt couldnt get any further the pH was decided by other factors, obviously more acidic ones by our calculations.

Strong wind and dry conditions, not good for most plants, wind would have swept water away, maintaining the movement of water out of the plant through transperation, plants like marram grass  and couch grass have adapted to these conditions by bending their leaves/blades, so they dont loose water as readily. these are called pioneer species, because they can withstand the harsh enviroments, and as they die, biomass builds up and succession takes place.

Evaluation

The measurment of the 20m streches was not accurate, as we had to follow paths, which meant we only got plants that were resistant to being trodden on, which would have limited our range of plants to be found. The data collected could be assumed to be accurate, as it follows the requirments for succession, but i do not believe it to be wholy accurate, for the reason stated above.