Tuesday, January 29, 2013

Ecological systems: an example from Africa

Here's a quick post to review the concept of systems, in this case ecological systems, which were mentioned in the last post.

An ecosystem, like other systems, is a collection of interdependent and interconnected parts that function as a unit and involve inputs and outputs. It is also complex and needs all its parts and intricacy to work properly.

In the case of an ecological system, the living parts -- animals, plants, fungi -- interact with each other and with abiotic (non-living) parts -- the air, water, and mineral soil -- through the transfer of nutrients and energy.

Here's a simplified example:

1. A lion in eastern Africa eats a topi antelope, taking in the nutrients, water and energy of the antelope.

2. The lion continues to eat topis for a few years (and is justifiably unwelcome at antelope parties).
3. The lion dies, and its nutrients and energy are transferred to vultures and to the soil, where bacteria and other microbes break down the organic material left by the vultures and convert it to soil nutrients.

4. Wind carries grass seeds to this same patch of soil, while the sun beams down energy to the whole area.

5. The grass seedlings absorb water, nitrogen and other nutrients from the soil, and carbon dioxide and solar energy from the air and combine them through photosynthesis to produce sugar and grow.

6. An antelope of the future eats the grass and converts the energy (sugars) and water from the plants into its own tissue.

7. Repeat as needed. Requires additional grass, gazelles, lions, vultures, microbes, soil, wind, sun, and water to carry on.



Use diversity to get more from your forest!

We need all our parts!

In our race to be the fittest species of all time, we humans have perfected the art of manipulating natural systems, often simplifying them down to a single species (think corn, pine, rice, oranges, cows, salmon).

Single-species systems don't really exist naturally - even Antarctica, which is 99% covered by permanent ice and snow, has over 450 plant species and around 200 species of invertebrates crawling around there as well. Add to these all the plankton, fish, seabirds, penguins, seals, and whales that live off the coast and you have a diverse and active place.

Gentoo penguins add to Antarctica's biodiversity
photo: PaoMic, Wikicommons

Obviously, the simplification perpetuated by human activity downgrades the fitness of all those other species that no longer live in these places (these places being 50% of Earth's ice-free land area!).

But, as we learned in a previous post, ecological systems are typically complicated and interconnected, and, like other systems, need all their parts to work properly.

Tuesday, January 22, 2013

Why should I care about biodiversity?

How to simplify a prairie, and why we shouldn't

In the last post, I just touched on the astounding diversity of life on Earth. As humans manipulate natural environments, we tend to simplify them – reducing the complexity of the vegetation and number of species of everything to such a degree that, in some places, only a few living things survive.

in the cornfield. photo: Lars Ploughman

Robert Krulwich’s review of Craig Childs’ book, “Apocalyptic planet; field guide to the everending earth” describes how Childs found “almost nothing” living in a cornfield in Iowa. Krulwich writes: “Cornfields...are not like national parks or virgin forests. Corn farmers champion corn. Anything that might eat corn, hurt corn, bother corn, is killed....” In and around the corn stalks, sitting on what was one of the world’s richest soils, was a denuded landscape with no birds, no bees, no buzzing insects, just a single plant species (corn), 1 small mushroom, 1 ant, and 1 red mite (just 2 arthropods!!).

The downgrading is pretty depressing. This loss of biological diversity eliminates or decreases pretty essential ecological interactions and processes (aka ecosystem services), such as providing food, energy and minerals, filtering water, capturing and storing carbon dioxide, dispersing seeds, and pollinating crops.

bees pollinating basil
photo: Matt Mets

bee pollinating onion
photo: Gary Halvorson, Oregon State Archives

For example, as native forest, shrub, and prairie is cleared, fewer wild bees survive, which cuts pollination not only of wild plants but also of many key human crops (note the bees in these 2 photos). Similarly, as different earthworm species disappear with the loss of forest, soil formation does too.

But how valuable is pollination or soil formation?  Read on!

Monday, January 21, 2013

What is biological diversity and why do we have it?

Back in November, before the holiday feeding frenzy got me writing mostly about food and exercise (2 of my favorite subjects!), I introduced some basics of genes and genetic expression, the basis of all life (yes, you too!).

so true!  image: Funny Pictures blog
I know, these subjects don't tempt in quite the same way as Christmas cookies...but while you are what you eat, even this depends hugely on what your genes dictate, so they're worth revisiting.

Genes, brief review

Genes are units of DNA inherited from our parents that carry information that determines our physical traits, which, in turn, affect our relative fitness (our ability to survive and reproduce compared to others) in a given environment.

image: Hudson Alpha
Each cell in our body contains over 20,000 genes, and tiny changes to just one of them can cause variation among individuals, even in the same species.

We humans display a range of countless features: hair curliness, dimples, skin and eye color, height, voice clarity, toe length, and running speed, to name just a few.

And that's just within our single species! What about the others?

Species diversity

As you might guess, variability in the expression of many individual genes leads to even greater variability among the different animals and plants that are made up of those genes. My last post showed some of the incredible beauty and variety found in just 4 groups of insects.

In fact, scientists have identified roughly 1.3 million species, but they estimate there are far more that remain undescribed. These are the species that haven’t been found yet, haven’t been catalogued, or are actually different than what we think they are.

tarantula neighbor in Costa Rica
sponge with other marine inverts
photo: Peter Southwood
Most of the world’s species are small invertebrates (they have no backbone), such as earthworms, arthropods (e.g. insects, spiders, lobsters...), sponges, starfish, and protozoans (single-celled micro-organisms). Even within this group, arthropods rule.

Scientists who recently surveyed sections of a single rainforest reserve in Panama estimate that 25,000 arthropod species live in the 6,000 hectare (15,000 acre) reserve. Yes, four times more arthropods live in that reserve than there are mammals on earth.

This means that you could find 300 species of arthropod for every mammal species, 83 for each bird species, and 20 for each plant species! In other words, most living things on earth (minus single-celled creatures) are arthropods.


What's your favorite arthropod?



Next post alert: Why you should care about biodiversity!

Thursday, January 17, 2013

Get outside!

And plant some trees in your neighborhood while you're at it, because the natural world is good for you! (I know, you knew that already, but here's some data to back you up.)

Evidence from several scientific fields has suggested that contact with the natural environment can improve human health. A new study by the U.S. Forest Service, using a natural experiment (a beetle infestation), found a relationship between the loss of trees (from the beetle pest) and an increased number of human deaths from respiratory and cardiovascular-related diseases.

This pattern of higher mortality rates was seen repeatedly in U.S. counties with very different demographic and socioeconomic makeups.

The findings contribute to the growing medical evidence that the natural environment provides major public health benefits.

Trees protecting Ontario's public
photo: Landscape Ontario
While the researchers highlight the relationship found between human health and the presence of trees, they haven't yet determined its cause.

In fact, trees provide us with a whole host of benefits!

Trees improve moods and emotions, provide privacy, block urban noise, absorb pollutants, produce oxygen, conserve soil and water, provide beauty for us and habitat for animals, and even save energy by blocking winter winds and providing summer shade.

So there's never been a better time to plant and enjoy trees. (Yes, even in winter!)



Here's the original paper in the American Journal of Preventive Medicine:

Geoffrey H. Donovan, David T. Butry, Yvonne L. Michael, Jeffrey P. Prestemon, Andrew M. Liebhold, Demetrios Gatziolis, Megan Y. Mao. The Relationship Between Trees and Human Health. American Journal of Preventive Medicine, 2013; 44 (2): 139 DOI:10.1016/j.amepre.2012.09.066

Saturday, January 12, 2013

Exercise in the New Year (and beyond) 4: no motivation?

So you have some time, some money, and you can't really say you are too sore from your hard workout yesterday (but see here for tips to bust these excuses)... it's just...

No motivation? (i.e. It's boring, or nothing works for you?)


image source: Exercise for PINK
If you're dreading starting an exercise program or continuing your current one, change may be what you need!

Take a minute to ask yourself these four questions from Stanford University's School of Medicine:
  1. Are you enjoying the activity, or is it just something you think you should enjoy?
  2. Is your workout at the right intensity - are you comfortable with the pace?
  3. Are you on a realistic schedule - would a schedule with fewer days but longer exercise periods be more convenient?
  4. What benefits did you originally gain from the activity, and are you still finding them?

What to do if your current physical activity is just not at all fun and you're too bored to keep it up?

There really ARE plenty of ways to keep up your enthusiasm about exercise, and they don't necessarily include hard liquor!

Exercise in the New Year (and beyond) 3: too tired?

Too tired? Too weak for a (tougher) workout routine?


photo source: Exercise for PINK
Yes, workouts can be hard, but there are answers to this excuse as well! (See 1st post in this series on exercising when you have no time)

Unless you are avoiding all communications media, you know that exercise is important for maintaining both physical and mental well-being.

If you work out regularly, you either love it or you at least value these benefits. If you don't exercise because you feel too tired or weak to start, you've got a Catch-22 situation: feel tired and don’t exercise and you’ll probably continue to feel tired!

Exercise actually invigorates, so if you can break that cycle, you'll feel more energized.

So what can you do if you are consistently too tired or weak to work out?

Exercise in the New Year (and beyond) 2: no money?

Excuses for avoiding exercise are so effortless and common, that I've assigned them separate posts!

photo source: Exercise for PINK
No time for working out is a big one that I addressed yesterday, but with all the hype about aerobics and weight lifting, and personal trainers, and the current economic crunch many of us face day-to-day, I wanted to stress that going to a gym is not a requirement for getting active!

This also applies to those of you who dislike gyms, so...

Excuse # 2: No money? (a.k.a. can't afford a gym)

If cost is your issue, remember that walking, running, push-ups, sit-ups, and dancing around at home are all free. Or try:

Yes, me, during my PhD years,
heading off to Uni
(Univ. of East Anglia) in the UK
(not known for its
dry sunny weather)
1. bike to work - transport and exercise all in one! Check out some tips and links for this in one of my earlier posts.

2. a no-gym workout at home - there are heaps of no-equipment workout possibilities out there, such as this one or this one. Or devise one of your own that is fun, easy to follow, and varied.

3. workout videos - boy, there are so many, I can't even begin to describe them. Workouts for various types of dancing, calisthenics, kickboxing and other activities are all over the web as well as on DVD. Here are tips for beginners for choosing one that suits.

4. circuit training - this is a type of interval training, with a variety of fast-paced, high-intensity exercises (the circuits), with breaks in between each combination of lunges, push-ups, crunches, jumping jacks, mountain climbers, punches and sprints.

You might explore Crossfit or boot camp workouts for particularly tough sessions in a group setting. These sessions are often more fun with a group, so you check sites such as Meetup.com to see if there is one near you.

5. Kids and dogs - If you have a built-in workout buddy dog, take it out for a spin and you both benefit! And your kids will love you for joining them in throwing a ball or frisbee, playing tag, taking them hiking or swimming or canoeing.

6. Get outside - Even without kids and dogs, going walking, hiking, running, climbing, canoeing, or skating the trails, rocks, rivers, and lakes out there are not only free or low-cost, but inspiring. Grab your water bottle, a hat and sunscreen, and a friend or two to go exploring your neighborhood, local park, or other natural area.

[ And if you do go to the gym, don't let current bigger crowds at gyms or other athletic facilities put you off -- apparently, 60% of gym memberships go unused, and attendance that rises in January apparently returns to normal by mid-February. ]

Next excuse: I'm too tired!

More excuse-busting articles at:


Friday, January 11, 2013

Exercise in the New Year (and beyond) 1: no time?

While we are still so early in the new year, during this period of fervor for getting (back?) in shape, I wanted to make a pitch for movement!

Yoga Master the octopus shows strength, style, flexibility, & cleverness

Wild animals earn their living by moving - there's no way to escape a lion or eagle, or catch a rabbit or mouse, or even enough fruit or insects, without being quick, strong, and agile.

image source: PrimePhysique

This was true for our early ancestors too, but for so many of us these days, being back at work means spending long hours sitting at a desk.

Over half of the human residents of this planet have access to food produced by others (serious note: roughly 40% of the world’s population are small farmers, who produce 80% of food in developing countries and often struggle to do so).

We the remaining 60% have the opportunity to do non-agricultural work, which is great for choice but often killer on our activity levels and, subsequently, our health.

The more we sit, the less we move; the less we move, the greater the risk to our health.

In fact, we humans were meant for physical activity!

Nevertheless, behavior is really hard to change (but here are tips to adapt a desk- & car-bound lifestyle (e.g. "Pretend it's 1985" and walk to your co-worker's cubicle to ask him a question). And sheer willpower is rarely enough to get us to keep our resolutions, as Life -- bad weather, sick children, working overtime, relatives visiting (Must.Clean.House!), fear of looking stupid, or even frustration with delayed results --gets in the way.

Yes, workouts can be hard, and excuses and procrastination are EASY.
   Not enough time.
        Not enough money.
           Not enough strength. Or endurance. Or motivation.

All of these may be true -- but they are not good enough excuses not to exercise!

In fact, exercise may help you deal better with a host of potential excuses, like a cold, a hangover, or a work presentation! Read on for some motivating ideas to keep you moving, even when time is short.