Tuesday, November 27, 2012

Climate Change and Assisted Migration

As gardeners we are, knowingly or not, involved in an act called Assisted Migration. It is definitely a 21st century term and it is defined as,  “Movement of species beyond their historical range either to prevent extinction due to climate change … or facilitate their adaptation to future or projected climate change”, according to Nicole Klenk , a social scientist at the University of Waterloo.  While gardeners of all types from all ages have always coveted what their neighbours had and we did not, we have transported plant and animal species from one country to another, over land and sea, in order to revel in and admire a new discovery, and to own one for ourselves. Today however we are doing this for different reasons, namely the continued survival of plant and animal species, and it is called Assisted Migration. 

Scientists have been studying climate change for a couple of decades and are now seeing ties to the loss of animal and plant habitats. As areas of the earth are warming or cooling we are finding that some species are finding it difficult to adapt to the changes and are therefore at risk. There has been a slow movement by groups and individuals alike to protect the species we love by moving them to locations where they hope they will continue to survive for years to come. 
There are two cases of assisted migration in the news which involve moving a species far from its local habitat. The first is a conifer in Florida, Torreya taxifolia, with a shrinking range in the Florida panhandle. The group Citizens of Torreya Taxifolia Guardians are planting seeds of Torreya taxifolia from private stock or garden centres outside of its northern range in North Carolina. 

Link to Torryea Guardians

A second example headed by Richard Branson of the Virgin Group was to move Madagascar lemurs onto an island that he owns. The plan was to move animals from zoos or private organizations with the intent to protect the species. Conservation scientists criticised him for potentially creating risks to other species on the island. These examples are of citizens making choices on their own (which may be ill informed) and without any government and academic oversight. The concern is that these types of assisted migration may cause more harm by changing native ecosystems. However these actions are also presently perfectly legal.

The philosophy of what we are doing concerns Anthony Ricciardi an Associate professor and invasive species biologist at McGill University. He is not opposed to assisted migration or what he calls assisted range expansion, but the intentional moving of species, such as moving animals to another island. We have a long history of moving plants and animals around the world and have caused some degree of ecological damage by degrading habitat, introducing diseases and pests, and the extinction of native species. Do these long distance introductions such as moving certain plants or animals outweigh the risks of ecological damage? Mr. Ricciardi claims there are no reliable ways to forecast the risks of a species introduction. There are risks with assisted migration such as, creating new invasive species, the effect on the local ecosystem, and the interaction with local species.  He says we need to deal with the root cause rather than moving species around.

The Emerald Ash Borer is quite destructive in parts of Canada and the US. Brought in on packing crates from China.

British Columbia is presently a world leader in a large scale experiment of assisted migration. They are moving 15 tree species (of commercial value) to the northern edge of their range with the intent to study their adaptation to future climate change. They are hoping to develop a seed bank that will be successful in providing trees adapted to a more northern range. To determine success we must wait 15 to 20 years and expect that up to 50% of those seedlings will not survive. 

Professor Sally Aitken in Vancouver, a Forest Geneticist at University of British Columbia, is working on an experiment to save the white bark pine. The white bark pine is listed as threatened in Canada and is in rapid decline in western Canada and USA due to white pine blister rust, the mountain pine beetle, and loss of habitat. This pine has many positive ecological ties to the ecosystem that scientists consider it worth trying to save. As part of a controlled experiment they are moving it by seed within its existing range, to north of its range and in places where it is not expected to survive in BC. The only risk is increased invasion of the white pine, but since it is a slow growing and moving tree the risk is very small, as well, the ecosystem the pines are planted in is already part of its regional flora.
How can we mitigate the impact of carbon emissions on ecosystems? While this is a controversial and difficult problem to solve, we are attempting different ways of dealing with it by assisted migration taken in tiny steps as with the tree studies, and in large steps with the removal of species to areas outside their natural range. Some will argue we need to be working on the root cause. Who is right?

Marc Roberts

(Information taken from the CBC radio program “The Current”)

Monday, November 19, 2012

Guell Park, Barcelona

You would have thought that the gardener in me wanted to ensure a visit to the botanical gardens in Barcelona Spain. It turns out a week is not enough time to do everything on the list and the gardens were missed. 
Primary on the list was to visit all the Antoni Gaudi buildings that we could. Gaudi is called an architect but truly he is a visionary. His career spanned the late 1800's into the early 20th century of the Modernist Period or Art Nouveau period. He had luck on his side as he found his patron and client in Eusebi Guell early in his career. The homes and other buildings such as the Basilica Sagrada Familia could not be built today as they involve immense skilled labor not to mention high quality and expensive woods, stones, glass etc. For a gardener or naturalist, however, Gaudi's works are a joy to behold. Nature is part of his design whether it is the swirl of a shell or an obvious creature like the salamander.
Let's have a stroll through the gardens of Guell Park.

Coming in from the hills on the west

The main building in the park is by the front entrance. It is a complicated structure that serves many purposes. First you are greeted by a large staircase with the dragon that is a fountain which flows to a pool below him.

Up the stairs and you are in a covered 'hypostyle' hall with columns. The square above is a large area for the public to get a great view of the city. Notice the mosaics on the winding bench that serves as the wall to the square. The square is actually a water collecting point that sends rainwater through the columns into a cistern below the hypostyle which is used for watering the gardens. Ingenious.

This is the ceiling of the hypostyle. Natural organic forms in abundance

We move on to another area. This a courtyard with columns of quite a different sort. Gone are the fluted columns and medallions of colour that represent stars ? shells ? and we are surrounded by rock and stone.

Close up of the planters on top. They are filled with succulents like agave and yucca.

The inner courtyard below is made to resemble trees. Each column is made of stone and each one is individual from the others. Walking paths are above the courtyard and provide the shrubbery that is the trees canopies.

In the photo below, the columns create a wonderful covered portico and are of course skillfully arched.

Lady with pot on her head

The next photos are of some of the flowering plants we saw. Unfortunately I still don't know what they are - I had intended to try and research Spain's flora but never did. These were plants that we saw in many areas in this park and others.

The blue is ipomea or morning glory.

Agave's in the dry soil

These were in planters throughout the city as well

Bougainvillea 1

Bougainvillea 2


     A soft pale blue. Looks phlox - like

This is a stunning flower

Very pretty too. Notice that a lot of the foliage is greyish which tells you how little water they get.

Flowering  agave. Unfortunately too high to see the flower. I am standing at the same level as the plant in earth.

Barcelona is a beautiful city in Spain. We loved every minute and hope to return one day as we do for Amsterdam. Next time I will buy a book on the Spanish flora so I know what I am looking at.

Monday, November 12, 2012

de Hortus Botanical Gardens, Amsterdam

Back in September hubby and I enjoyed a wonderful week in the city of Amsterdam, Holland. The city is probably best known for its canals, bike riding citizens and it's views on marijuana.
We spent half a day at the small but wonderful Hortus botanical garden just on the edge of the city. Created in 1638 it is one of the oldest botanical gardens in the world. It houses a Palm House, a Three-Climate Greenhouse, a small butterfly with cacti greenhouse, a wonderful organic restaurant under the trees at the Orangery, plus some lovely gardens. They claim that the Hortus houses more than 4,000 different species of plants, which is about 2% of all plant species growing on Earth. The Hortus specializes in Palms, Cyads, South African plants, carnivorous plants and are very proud of their herb garden the Hortus Medicus. The Hortus Medicus is a medicinal herb garden which was of vital importance in its time as it provided herbs to doctors and pharmacists of the 17th century.

Upon entering the gardens we first came across a large pond with waterlilies. There was even a beautiful bud emerging.

Here I am in the Semicircle. The Semicircle has an interesting idea behind it. I give you their words to explain; " The Semicircle portrays plant systematics: species that are closely related can be found growing near each other, while those that have little in common are grown far apart. This is the first and only systematic garden in The Netherlands in which the plants are categorized according to 'molecular systematics'. This kind of systematics is based on the similarities between genetic material."

Semicircle - photo from Hortus Botanicus Amsterdam

And if you really want all the details:

The tree area had many many gorgeous trees, especially conifers. I give you one gnarly beauty and the Wollemi Pine. This pine died as you can see but they did have another in a greenhouse that looked healthy.

Dead Wollemi PIne

The Wollemi Pine is an ancient tree (290-200 million years ago) thought to be extinct but found in Australia in 1994. World wide conservation of this tree began in 2005. The Royal Botanical Gardens in Hamilton also houses a Wollemi Pine. It took many years for Australia to grow new seedlings in order to distribute them across the globe to other botanical gardens.

Below are two photos of the Palm House. The cool thing about this conservatory (besides the plants) was the stair and catwalk that allowed you to view the plants from a height.

From above

I did manage to find the hardy carnivorous plants in a small bog outside the Palm house, the rest were in the South Africa conservatory.


We moved into the Three Climate house, which very cool and very hot. These photos are primarily of the jungle in the hottest of the houses.

Notice the pink bud to my right. No idea what it is.

Pink bud
Bottlebrush ?

Very thorny tree. I never saw the top of it.

Tillandsia mallemontii

 We left the humid jungle behind with sweat was dripping off my forehead - not something a girl from Canada relishes. The South African house was dry and cool and a relief after that.

It was here we found the second Wollemi Pine. Doesn't it look nice? and alive? The first one had been grown outdoors and was killed by a frost. 

I don't know what this is but I love it. Like a yew with fushia-like flowers. Nice.

Last, a few photos from their butterfly house. The house also held cacti but I don't remember them and I certainly did not get any pictures of them. I was concentrating on capturing the few types of butterflies they had, but the darn things kept moving around.

Poor old tattered flutterby

Must be a lot of fighting going on. More torn wings.

That is all of my visit to the Hortus Botanicus in Amsterdam. It would be nice to visit again in late spring early summer to see more of the flowers. We did have a lovely lunch out doors by the Orangery. Organic salads with really interesting and flavourful flourishes. They also have a very nice gift shop too. If you would like more info on the gardens click here to get to their web site.