Alien attack… Invasive plant species and how to deal with them. part 1.

What is an alien species? You may well ask. It is not something that has crash-landed here from outer space or even from 1950’s Hollywood, although in some respects one could find similarities (and I have used that analogy in my Bloom 2013 garden to highlight the crisis http://www.bloominthepark.com). Rather these aliens are essentially non-native species that have been introduced to our island, sometimes intentionally, other times unintentionally, from other regions of the world. Once established into our indigenous ecosystems they commence to either outright run amok our slowly, insidiously, begin quietly displacing the original native inhabitants. So they are not a good thing. That said when I write words such as ‘insidious’ or ‘running amok’ I get a slight cringe of am I being extreme, these words in other contexts have been utilized by xenophobics and genocidists to justify hate and evil deeds. One can’t hate these invasive species, especially the botanical invasives which this article focuses on. In fact one must marvel at their tenacity and capacity to stay alive, propagate and thrive, by some amazing evolutionary tactics. The problem is that all that is at the expense of so many other species. These aliens are in reality on the attack. Colonizing with blitzkrieg efficiency and ruthless old roman decimation of pre-existing flora and fauna from the new territory they gain every day.

The ‘invasion of the body snatchers’ hysteria surrounding them is often justified as they can displace not just local populations of native plants but the insects, birds and animals linked to those plants. It is not just habitat destruction but food chain disruption that makes them a serious ecological threat. They are the plant equivalents of the grey squirrel, cruel and ruthless beneath the cute appearance. Not only are they making devastating inroads but their impact will be long felt. Some can change soil ph., some can transmit diseases to crops and forests and some can even poison livestock and foraging animals and pets. All can change the landscape of your childhood in a manner that would render your descriptions alien to your children’s grandchildren if we don’t try and reverse their gains, if not eradicate them fully from our shores. They will still thrive in their native places of origin so that task is not extermination off the face of the planet.  This is more like weeding on a grand scale than it is hunting to extinction. There is not an ethical dilemma to face as such and no dodos will get hurt in the making of this article or your responding to it.

There are arguments that this is simply survival of the fittest and we are just in the midst of evolution at play. Well oak woods and native bluebells are hardly lumbering dinosaurs and their replacements of rhododendron and Spanish bluebell are hardly cattle and gazelles.. as in are hardly the most functional, productive or beautiful. A native oak will support a plethora of wildlife not just as a winter food source for red squirrels, pigs, deer and jays but during spring and summer it acts as an enormous food supply as its foodchain is webbed out from the hosting of 284 associated insect species. Think of the birds that survive off that. Think of the fox that harriers your chickens because the woods have a scarcity of birds. The knock-on is enormous. Oak foliage is fodder to numerous and its decaying matter feeds the soil and boosts fertility of the district it grows in. on the other hand, non-native rhododendrons are invading and outcompeting oak woodlands. These replacements have toxic leaves and offer no sustenance to herbivores and so decrease local carnivore species, the insects that can tolerate the toxins are not natural to Ireland and so its lack of support to naturally occurring species of insect and bird is effectively collapsing  food chains and foodwebs in their wake. The falling leaves of rhodos acidify soil and lower fertility, even pollute waterways. This is not an evolutionary leap forward. No more than cancer is evolving humans. Strong words… but it is easy to do nothing as if the will of the universe or god is at play. Man introduced these species. Man must take responsibility. Like it or not the invasion is happening on your watch.

About The Holistic Gardener

I am a horticulturalist and writer interested in how the garden and engagement with nature facilitates full potential living and therapeutic benefits.
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