Rarangi field trip

Yesterday we had the Bio field trip to Rarangi. As has been the case on all of the trips to Rarangi over the past few years we had torrential rain.

However, even so, the trip did succeed. First of all it indicated that biologists have to collect samples in all weather. This also means that you need to have a plan and work together as a team.

The three transects had plants showing zonation. We will need to work on analysing the data (which we will do as a practice 2.6 assessment).

And THANKS to all parents who helped in transporting the boys- much appreciated!

Kite Diagrams and Sampling

Today we discussed how to a) record data during an ecological visit and b) how to present the data in a meaningful way.

The key things that we look for are:

a map- showing where the samples came from, this can give an idea of some of the biotic and abiotic factors that are in operation.

Clearly indicated transect numbers, listing the species and how many.

This can then be used to create a kite diagram.

The kite diagram shows how a species changes as the position along a transect changes.

I gave out (made up) data and a sheet of graph paper. The first part of the homework (due Friday) is to draw a kite diagram for the sample data.

The second part of the homework is to watch a video and answer the questions at:
http://zapt.io/tx3vsafj

Remember to use your school google login to access it.

Succession

Apologies for the late blog post- the school network had an issue that prevented accessing our Google Accounts, which means blogger was unobtainable.

In yesterday's lesson we introduced the idea of Patterns of Communities.

Living things colonise barren rock, eventually leading to soil formation and more complex ecosystems. This is Primary succession.

When there has been a minor change in a habitat, this leads to Secondary succession, which is far away the most important type of succession on the Planet.

We discussed this and watched a video here

Also- I issued the hard copy letters for the trip next Tuesday and reminded about the need to return slips for the Lake Rotiti trip.

In today's lesson we discussed the different types of patterns and the class made extensive notes on succession.

Sampling Practice

Yesterday we went outside and practiced with two different sampling techniques.

The first was pooting. This involved finding small invertebrates and sucking them up into a pooter. This highlighted a) ethics and b) the need to have a fair, unbiased plan (otherwise you just target insects that you like or are interested in).

After lunch we looked at using quadrats on a line transect. Obviously the school pitch is not the most variable or exciting areas to investigate, but it does give an idea of how much work is involved (especially as you are carrying out samples every 40 cm).

A reminder- I am hoping to be able to take you out to Rarangi in the second week back after the holiday- parental help will be essential for transport if this is to be successful.

Course discussion- Piazza

I think it would be a good idea to have a secure place where we can hold discussions about course content, e.g. asking questions, requesting help (from me and each other).

We are going to trial Piazza as our discussion platform- you have all been invited (only students at school in the class can enter the group, sorry parents!).

The web address if you forget it is: https://piazza.com/mbc.school.nz/spring2015/200/home

Remember- tomorrow (if the weather is good) is our opportunity to go and learn some sampling techniques outside.

Introduction to sampling

In today's lesson we went outside to view the plant life on the school grounds.

On the tour I showed some areas where abiotic factors have affected the habitats and led to a variation in plant life found.

We looked at some of the very old trees on the grounds and saw that the bark provides a habitat for lichens and mosses. This is an excellent example to show Gause's Law in operation. There is limited space and variable abiotic conditions on the trees leading to differences in the types of lichens found.

We then carried out an exercise to find out how many different plant species occurred on the playing field and their percentage cover.

This was a trick exercise. It is almost impossible to succeed with this without a plan. Ecologists need to use sampling techniques that enable the accurate assessment of how much of any given species there are in a given area at a given time. This needs to be reproducible and carried out ethically.

Having tried ourselves to measure species with the incorrect way, we will now spend our lessons learning the different techniques to sample populations (plant and animal) and will eventually get to apply these at Lake Rototiti.

Finally, a reminder to get the Rotoiti acceptance letters back asap.

Fundamental and Realised Niche

Following on from the last lesson where we looked at Gause's Law of Competitive Exclusion, today we looked at fundamental and realised niches.

Fundamental niches are the entire range of abiotic factors that a species could survive in, even if survival is very difficult.

The realised niche is where you fine the majority of the species, after competition is taken into account.

We looked at a real life example to illustrate this, Brown barnacles and Modest barnacles.

Along the way we discussed how we account for tidal variations (using the mean high water mark and the mean low water mark). This will come in useful if you go on to study level 3 biology or marine science.