Woodland

Species Distribution Biodiversity in Beech/Sycamore Woodland.

Introduction

For our coursework we went to Weston Woods, Baldock, Hertfordshire. It was originally planted 200 years ago to provide the locals with beech furniture, which is called deflected succession*. The woods were planted on a chalk escarpment, and chalk is a poor soil for organisms and nutrients.

On the 16th of October 1987 a storm hit Weston Woods, previous to this a period of a drought had just taken to place therefore leading to the dryness and crumbling of the chalk. As the woods had been built on chalk, the trees had been uprooted by the wind of the apparent hurricane causing much damage to local buildings. Very little conservation was done to the tumbled trees and little was done by the CMS (Countryside Management Service). Because not much was interfered with, it would have naturally grown back, which is known as a succession**. Sycamore trees had started to grow beneath the soil, a process started by the hurricane, secondary succession***. For the reason that some of the trees weren’t removed, mainly thin sycamore trees grew closely together and fought for the light, they hadn’t grown before because the leaves off the beech trees had made it harder for them to photosynthesize. Other reasons were provided to contribute to the uprooting of the trees which include poor soil and shallow roots.

After a period of time, sycamore trees began to grow. They provided a much healthier and diverse undergrowth as sycamore trees do not secrete toxins unlike the previous beech trees.

Aim

The aim of my coursework is to compare the difference in biodiversity in two areas of Weston Woods and investigate the different types of plant species in the soil.

Prediction

I expect that beech woodland that is older is likely to have greater biodiversity*. There is an increase with biodiversity over time. The sycamore had less biodiversity as the tree ages are much younger than the beeches and the girths of sycamore trees will be much smaller because they are much younger than the beech trees. The vegetation which is on the ground around the areas where beech trees have been growing doesn’t really exist as the beech trees secrete toxins which destroy most nutrients. I also expect to see a range of saplings and species, for instance Sycamore (Acer pseudoplatanus), Ash (Foxninus excelsior), Beech (Fagus sylvetica), Yew (Taxus baccata), Hawthorn (Crataegus monogyna) and Elder (Sambuccus nigra). With the use of small quadrats, many areas will have plenty of bare ground because humans use the area, which trample the woodland leaving it unable to grow. Also it is used as a bicycle trail which further tramples the woods.

Fair test/Key variables

Throughout the coursework to keep it a fair test I am going to keep more or less everything the same other than the size of the quadrats and the locations of transects around the woodland.

• Same size quadrat (50X50cm2 see preliminary experiment)

• I used the same tape measure, same data logger.

• The only thing that I will change is the location of the transects. These should have been placed randomly (using a random number table) however I decided that I should avoid placing the tape measure where there had been serious effects caused by humans (i.e. paths, BMX cycle trails, lots of litter, site of previous fires etc.)

• Same people in our group taking the results. (Different people may assess the amount/ percentage cover of different plants).

The way I kept everything accurate and reliable was by repetition (We repeated the transect 2 times to avoid the possibility of any anomalous results), we did the experiment many times over again if any anomalous results occurred.

Safety

I will make sure that my experiment doesn’t pose any health hazards by sticking to the risk assessment. These include not swinging on tree’s branches, taking care when walking down steep areas and watching for exposed roots which we could trip up on.

Apparatus/Equipment

Below I have listed everything I will need to investigate this experiment:

• 50cm x 50cm quadrat

• Data logger (which will be used to measure the amount of sunlight)

• 1 tape measure (50m)

Method

There are many methods which I am going to use in order to find the results I need. I altogether had done 4 transects that were 100m’s long each. To do this every 5 metres we calculated roughly how much vegetation was in a quadrat (50cm x 50cm) and the ground cover as a percentage and plotted this into a table. In the same area we used the data loggers to measure the amount of sunlight and took note of this. We also used a bigger quadrat which we used with the tape measure and counted the types and the amount of trees in there and measuring tree girths. I came up with a preliminary experiment which was: What is the optimum size for a quadrat?

Accuracy and precision

I used a ID book to help me with my identification of the species present and when I had problems identifying species I asked Mr Cook (Biology teacher). I asked all 3 people within my group to estimate the amount / percentage and we often worked out a �verbal’ average