I posted another scientific story on the EOS-blog at SciLogs.be, this time about microclimate and plants. Unfortunately for my dear international public, these posts are in Dutch, but you can take my word on it that it is a big honour for a starting scientist in Belgium to blog for them!
Red clover at the warm side of a Norwegian fjord
San Carlos de Bariloche, Argentinia. The road to the airport is flanked by massive pine trees, blocking the view on the surrounding dry Patagonian steppe. They seem to flourish in this environment, although they are far from home. The new environment does not seem to stop them from growing tall and strong, and –most importantly – producing large amounts of seeds.
Those huge pinecones might have given it away, but pine plantations of every species can produce an enormous mass of seeds that dramatically accelerates the invasion process.
Pine seedling, the beginning of invasion
The impact of this seed rain is obvious as soon as one steps through the first row of planted trees. All through the Patagonian steppe, a mosaic of big, small and smaller pine trees is developping, turning the open steppe landscape into a conifer forest. The correlation with the planted seed source is obvious, with many and tall trees close to the roadside, from where they gradually decline in number and size over the next ten to hundreds of meters.
Pines invading the Patagonian steppe
This potential for spread outside the plantations and the massive impact of conifers on the native open steppe vegetation has sparked the attention of ecologists. Although many conifer species were introduced in South-America in the 19th century or earlier, the true large-scale introductions by means of commercial plantations only started throughout the 20th century. This makes conifer invasion a fairly recent phenomenon in South-America.
Invasion front, where pines are far from each other and limited in size.
This last fact might be an important key towards the management of the invasion. The introduction of conifers to South-America lags behind to several other important cases of pine invasion elsewhere on the Southern Hemisphere, like New Zealand, South Africa and Australia. With current conservation measures fairly weak in South America, it is really important to learn lessons from the successes and failures concerning past introductions elsewhere.
Experimental removal of pines to investigate regeneration of the natural vegetation.
Current investigations focus on the impact of these rapid changes on native ecosystems all over South-America. Changes in fire frequencies in the steppe, diversity losses in plants and animals, it all occurs in the shade of the spreading pines. Other important questions involve the abilities of the original vegetation to regrow after removal of the pines. More recently, we raised the question how this ongoing invasion might facilitate – or limit – invasion of other nonnative plant species. On that I surely hope to report in the future.
Pine invasion might replace the beautiful planes of the Patagonian steppe.
We will certainly hear more from these South-American pines, as they will more and more define the landscape all over the continent as they do in so many places all over the world.
Examples of literature:
Langdon B, Pauchard A, Aguayo M (2010). Pinus contorta invasion in the Chilean Patagonia: local patterns in a global context. Biological Invasions 12:3961-3971.
Simberloff D, Nunez MA, Ledgard NJ, Pauchard A, Richardson DM, Sarasola M, Van Wilgen BW, Zalba SM, Zenni RD, Bustamante R, Pena E, Ziller SR (2009). Spread and impact of introduced conifers in South America: lessons from other southern hemisphere regions. Austral Ecology doi:10.1111/j.1442-9993.2009.02058.x
I hope to get lucky the 20th of March! If weather conditions allow it, we will be able to see up to 90% of the solar eclipse in Belgium.
It would have been even better if I had fieldwork in Northern Scandinavia at that moment, but it will be an awesome experience anyways.
I made a lot of pictures in and around Belgium this winter. Find a nice overview of them in this gallery on the right of my blog.
The sun sets above the sea at the Belgian coastline, on one of these days that hint towards the approaching spring.
For plant ecologists, these hints of spring trigger the start of the fieldwork season. I am currently wrapping up the final analyses for my third introduction paper and, as from today, I start looking forward with full enthusiasm to the data collection and planned papers for coming season. I am sure it will bring so many good things, and I am ready to face them all!
I promise to keep you posted about all these adventures, from wherever in the world I will be.
Earlier, I wrote about the strong foundation that is needed to build houses in the dunes. 
Natures’ prototype of such a strong holdfast is found in the shape of European beachgrass, the true hero of the dunes. This species grows from a network of so-called rhizomes, that as no other keep together the sand and immobilize it.
These rhizomes have amazing skills for live in the dunes, one of them to grow two meters laterally every year, allowing the beach grass to colonise new areas in the highly disturbed environment at the sea shore. The rhizomes even tolerate a certain time submerged in water, so they can break off, drop in the water, come ashore somewhere else and start a new colony.
This species is unbeaten as king of dune fixation, and at this point still the best method we have to limit erosion in damaged dunes. Beachgrass hence serves a major role in the protection of the lowlands of Western Europe against storms and rising sea levels.
They are a perfect example of a stress-tolerant species. They can handle (certain levels of) the recurring disturbance caused by sea, wind, sand and rain, they know how to deal with the bad soil conditions in the dunes and they are true pioneers, as they will always be the first plant species to colonise the bare sand areas.
The true powers of plants never cease to amase.
Pictures from Bray-Dunes, Northern France
The 3D lab 