I recently celebrated my birthday by climbing sugar-loaf mountain with a group of friends, following the famous Costao de Azuca route. This allows for a mixture of steep hiking, scrambling and all-out climbing to reach the summit in about two-three hours.
As we tackled this adventure together, I was impressed by the changes in vegetation that we came across as we climbed closer to the summit. Interestingly, there were pockets of forest that we passed through.
Is this forest, isolated and quite difficult to access, primary or secondary rain forest?
Primary forest refers to forest which has never been felled by humans. This means the original biodiversity is much more likely to be intact.
Secondary forest refers to forest which has been felled and replanted by humans. Much of the forest in the Tijuca forest reserve lies in this category.
How would you tell the difference? Well tree height can give you a clue. Trees can live for hundreds of years if left undisturbed. As plants continue to grow during their lifetimes, this can lead to very large trees. The kind of trees that we observed seemed to have a maximum height of around 8 metres, and a DBH (diameter at breast height of less than 80 cm. These are estimates. These measurements don’t seem to be very large, but also one has to consider the limited soil – nutrient availability and the increased exposure to dehydration on a site like sugarloaf mountain.
So what’s the answer? I am reaching out to my ecologist friends for information. The guide seemed to think it was also secondary forest.
HOW do ecologists establish primary and secondary forests? Next time you are in a forest, take a look around you. Does it look like it was ever cut down and replaced?
Project-based learning is defined by Jay McTigh (Buck institute of Learning) as when “Students work on a project over an extended period of time – from week up to a semester – that engages them in solving a real-world problem or answering a complex question”. This semester, ib biology juniors applied themselves to the specific challenge of creating a field guide to the flora and fauna of Rio state. A biological field guide contains real photographs, taken by the author, and detailed classification according to the established rules of taxonomy (putting living things in groups).
this means that no google imaging was allowed. Students had to organize themselves to get out there, and discover some and photograph living species. There were thirteen major taxonomic groups the juniors were asked to find, three of them exclusively aquatic. Many of them are difficult to classify, and require detailed observations, followed by critical thinking.
Each group also decided to specialize in a certain taxa (group of animals or plants). Choices ranged from wild orchids, to the domestic dogs of Rio (apparently the phylogeny of dog breeds in Rio is quite fascinating. For example, that Yorkshire terrier on the beach at Leblon is actually a modified sub-species of grey wolf; Canis lupus domesticus.
The end result of the projects gave testimony to the high levels of engagement of this extraordinary generation of EARJ students. Videos of reptiles crawling into the sand dunes at Prainha, colourful powerpoints of arthropods collected from the walls of the EARJ buildings itself, and even a coffee table book; formed part of a powerful set of work that can be viewed below.
If you wanted to study the minute algae and hardy plants clinging to the open rock faces of sugarloaf mountain, you would probably find something new. I mean, how many biologists have the ability to fly? But what if you learned some of the rock climbing skills necessary. The EARJ rock climbing club has been practicing self-rappel as a slightly unusual way of going downstairs. Rappel gives you the confidence that you can go boldy where well, not noone, but only a few brave men and women – have gone before.
Any adventurous activity is made much safer by the presence of a loyal and trustworthy companion (or two).
Rock climbing is no exception. As rock climbing is being re-introduced to the EARJ this year, the student rock climbing president asked the coach to begin with some trust-building exercises within the students.
One of the exercises chosen is called the ‘trust fall’. A student stands on an elevated platform with their back to the group, and the group asks.
“How much do you trust us?”
” I trust you” They respond (hopefully!)
“Prove it!” replies the group. At this point the individual falls backwards, trusting completely that the group will safely arrest their fall.
So, the journey towards trust begins.
It is always exciting for a new teacher to start at a new international school. At the EARJ, I have immediately felt warmly welcomed by the staff, parents and the students.
There is something vibrant and kind in the culture of the school, and many people went out of there way to connect with me and talk about their interest in biology and the science department in general at the EARJ.
Not only that, the students immediately engaged with some interesting biological questions. I gave my ib bio class a so called ´Ubuntu challenge´.
Ubuntu is an South African cultural concept, which essentially means togetherness or unity. It is specifically expressed by a sense of identity through social roles, and not through ones own achievements.
The use of ´Ubuntu challenges´ in education was pioneered in South Africa by educational researcher team led by Baken Lefa at the University of Cape Town.
An ´Ubuntu challenge´ video made by previous students illustrates the main principles:
At the EARJ, students were challenged to come up with a method of measuring the speed of a nerve impulse travelling through a human body.
This is a clip showing their progress. I will upload a full explanation upon request.
Very happy to be an active member of the EARJ!
Designing your own experiments for the purposes of following an inductive line of enquiry is, well, the heartbeat of modern so called ‘hard science’.
IB juniors were challenged this week to create experiments which investigated factors which affect reaction times in Lincoln students.
Reaction times are a measurement of the efficiency of what neurologists call a ‘stimulus-response pathway’, a pathway that ‘bio-electricity’ passes through the body in order to coordinate a response. Processing time in the specific parts of the brain are also involved.
There is a whole wealth of contributing factors involved in determining how fast a Lincoln school student reacts to something.
Each IB student constructed their own research question, and followed their own line of investigation. Students with similar areas of interest collaborated, to allow for complex methodology and sufficient data collection.
Student interest included:
- participation in team sports
- different flavours of candies and taste-activated response
- coffee drinking
- amount of sleep
- length of time spend sitting in one place
(thanks to students for permission to publish these photos. Please contact me if there is an issue with any published photo)
It is well documented that young adults have a need for play in their daily lives, and that combining learning with play can be successful.
In my own practice I am curious about the process of ‘ constructing memory’ and the role in learning. I have learnt that for many students combining a word with a kinaesthetic motion enhances retention.
This morning as a bit of fun and as a lesson summary, the class made charades for the enzymes involved in DNA replication.
A few months ago the Lincoln school acquired a unique resource; a therapy dog, Jake. Jake can be reserved by classes, or visited by appointment. Scientific evidence is mounting that owning a pet can improve your cardiovascular and mental health. Blood pressure, pulse rate and incidence of heart disease have all been lowered in recent science studies (time magazine). According to a recent article in time
“In one study, a stressed-out group of adults were told to pet a rabbit, a turtle or their toy forms. The toys had no effect. But stroking a living creature, whether hard-shelled or furry, relieved anxiety. It worked for people regardless of whether they initially said they liked animals.” (time magazine).
What is stress? According to a journal review article on proven stress therapy (), stress is defined as something that threatens the homeostasis of an organism, or a perception of danger. Stress is bad for you. At least, in the chronic sense (long-term, rather than acute). I remember attending a conference where the famous cancer investigator, Dr Bruce Ames (of the Ames test), said that “there is not one single human disease that is not made worse by stress, including cancer”. This should be differentiated from ‘excitement’, or emotional arousal, in that the emotion experienced is one of danger or intense worry. It is noted by psychologists that although stress has a physical manifestation, such as higher pulse rate, it begins in the brain with stressful thinking (Bless and Grousse). Short bursts of worry, such as the rush of emotions when taking an IB exam, may not be so bad for you. This is an acute experience of stress, and should be followed by relief – the outpouring of laugher, shared experiences and commiseration that can be seen outside any exam hall. Chronic stress is experienced when there is no relief, or too little relief.
And it’s a problem in schools. Studies carried out in 2004 (UK, MRC), 2014 (in the US), and others have stated that ‘students are stressed like never before , or like adults’. Which brings us to the interesting part. How do we deal with stress. We can try to tackle the cause, or we can seek to reduce the stress through stress therapy. Enter Jake the dog.
This week in IB Biology students looked at four indicators of stress:
- Pulse rate
- Blood pressure
- Electrocardiogram (ECG/EKG)
- Spirograms, or graphs showing patterns in breathing
One class looked at music therapy, by choosing a song which was voted by the majority of the class as being the most relaxing – “Jack Johnson’s beach strummer – Banana pancakes”, subjects were treated to a seated listening session of this tune while the apparent effect on these stress indicators were measured.
Results are still being collected, stay tuned for the results!
- Bless and Grousse. Science and emotions after 1945. University of Chicago Press.(2014)
- Teens more stressed than ever before. accessed from (https://www.nbcnews.com/health/kids-health/teens-more-stressed-out-adults-survey-shows-n26921)
- Pet therapy: science proves owning a pet…accessed from (http://time.com/4728315/science-says-pet-good-for-mental-health/)