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The United Kingdom was once a superpower that was at the forefront of globalisation during the zenith of the British Empire. One of the major negative effects of this fact was the intentional and accidental introduction of many invasive plants to the island country. Most of which directly competed with local species and caused them to get displaced in an abrupt manner. Although the British government today maintains a program to eradicate non-native flora, their efforts have been in vain.
It’s important for every citizen to know how to identify the major invasive species that are currently wreaking havoc on the island’s ecosystem. After all, they are also directly affected by the matter as introduced plants have the potential to cause levels of agricultural production to plummet. Aside from that, they can also bring misfortune to animals that rely on the native plants which they compete with. With that said, we understand that it can be quite difficult to identify invasive flora because they often easily blend into the surroundings and don’t look foreign. Henceforth, we have decided to take it upon ourselves to enlighten others by listing down the most damaging invasive plant species in the UK. Japanese Knotweed The Japanese knotweed was intentionally brought over from East Asia as an exotic ornamental plant. Sadly, once it escaped the gardens of local homeowners, it quickly spread and is now extensively found all over England and Wales. Recent findings have even shown that the plant has also expanded into Scotland and has the potential to reach Ireland. One of the problems why people have with this species is that it’s very hard to eradicate because it reproduces quickly and is extremely hardy. Even if the cool winter temperatures destroy its visible parts, its extensive root system allows it to recover during springtime. While herbicides are proved to be effective versus the plant, it can take years for them to effectively get rid of it. Because of that, arborists are often forced to eradicate the species by painstakingly digging out its roots. However, using this method requires one to be extra meticulous since even the smallest rhizomes that aren’t destroyed can birth a new plant. Giant Hogweed People often innocently mistake the giant hogweed for an overgrown cow parsley plant because they look very similar to each other. However, this invasive species from the Caucasus has the ability to cause severe harm to a person when it’s ingested or touched. The reason for that is because the plant’s sap contains several irritants that naturally developed to protect it. Although it isn’t as difficult to control as the Japanese knotweed, this species has also presented itself as a headache for arborists. Due to that, a considerable amount of attentiveness is necessary when dealing with the plant. Without that, performing eradication measures shall often be ineffective and thus, a waste of time. Today’s tree surgeons commonly use glyphosate to control giant hogweed infestations. It is also possible to manually get rid of the species by uprooting it. Needless to say, it’s essential to be careful when doing so since the plant’s sap may cause people to get very irritated. In some instances, extensive contact can even lead to a skin condition called phytophotodermatitis which brings forth large blisters and scars. Common Rhododendron Individuals who first brought the common rhododendron to the UK did so with good intentions as the plant produces some of the world’s most beautiful flowers. The ornamental value of the species is undoubted but its ecological impact is also unprecedented as scientists from the Forestry Commission have successfully proven that it reduces the number of earthworms and birds in the areas where it’s planted. Herbivores like squirrels and dormice that feed on the invasive plant can get sick or even perish as the alkaloids that it contains are toxic. Fortunately, humans don’t have to worry about getting into contact with it since it doesn’t introduce any conditions when it’s simply touched. Arborists nowadays have found that injecting the common rhododendron’s stems with certain types of herbicides is the most effective way to keep the species from spreading. A major downside that comes with employing this technique is that it can take a months before the plant completely dies. Luckily, researchers from all over the country are currently working hard on developing new methods to keep this Southern European native’s population in check.  English Oak England was once extensively forested during ancient times. Unfortunately, most of the country is no longer how it was due to extensive deforestation that occurred throughout the centuries. In a way, the aforementioned fact is rather sad because a region’s flora often forms an integral part of its history and culture. It’s mainly for that reason why one should know what species of trees grow around them. However, only a handful of individuals that reside in England are equipped with that knowledge. Because of that, we’ve decided to help out by listing down the five most abundant species of trees in the country.
Sweet Chestnut (Castanea Sativa)A bowl of roasted chestnuts is a delightful treat which is rather hard to pass. It’s the product of the sweet chestnut that’s found extensively throughout the British Isles where it grows naturally and is also artificially propagated. The tree is easy to identify in comparison to other species of chestnut trees because to the fact that it yields smaller-than-average nuts which grow in clusters and are enclosed in a seed casing that is covered with spikes. Common Ash (Fraxinus Excelsior) The common ash is true to its namesake in the sense that it’s the most common species of ash that grows in the UK. What’s nice about this certain species is that it grows rapidly and produces wood that’s incredibly resilient and has many uses. As a matter of fact, it’s a staple of the timber industry in many countries because of that. A quick way to spot and distinguish the tree among others is by looking at its distinct leaflets that are lance-shaped with toothed edges. Silver Birch (Betula Pendula)One of the most prised ornamental trees in England is the Silver Birch. People can easily find it growing across the countryside and in urban settings because its bark has a distinct colour that can range from off-white to grey. Like the other trees on this list, this one produces valuable wood and that’s widely used to manufacture a countless number of products. An interesting thing about the Silver Birch is that it’s the only tree on this list that has a symbiotic relationship with the common toadstool mushroom (amanitas muscaria). Aspen (Populus Tremula) Aspen wood is known for having a low rate of flammability and is commonly used to manufacture matches and paper. In addition to that, the species is unique in the sense that it doesn’t naturally produce irritants called phenols. To properly determine if a tree is an aspen, one should look for its petioles which are almost exclusive to it as many species in England don’t have them. Sessile Oak (Quercus Petraea) While there are many species of oaks, the sessile is arguably the most common species that grows in England. The tree is arguably one of the most economically important ones in the country because its wood has a plethora of uses which include ship construction, luxury furniture, paddles, and thousands of other objects. Now to determine if a tree is a sessile oak, individuals should look at its uniquely shaped leaves and acorns which fascinatingly lack stalks. People generally don’t know much about the hundreds of plant diseases that afflict the trees which grow around them. Unfortunately, it’s for that reason that more are unable to identify whether a specimen is sick or not. As a result, hundreds of trees die on an annually as a direct consequence of this sad fact. Hence, it’s vital to educate oneself on the many common illnesses that take the lives of many trees around them. After all, the majority of which is brought forth by a large group of pathogens called phytophthoras.
The etymology of the name phytophthora originates from the Greek language. It combines the words “phyto” and “phthora” which means plant and destroyer respectively. As such, the term phytophthora directly translates to “plant destroyer” in English. If anything, that alone should raise alarms and cause individuals to eradicate the pathogen in all its incarnations. To help you, we’ve decided to list down is a list of the most prominent species of phytophthoras in the UK.
Acute oak decline is an unexplained natural phenomenon that has been decimating the population of the Welsh and English oak trees for over three decades. It most commonly affects mature English and sessile oaks that are over about half a century old. The issue has also been found to bother younger specimens and several other subspecies of oak trees.
Afflicted specimens often always have vertical, weeping fissures that give off a black liquid that eerily looks much like blood. Lying beneath that is a lesion wherein living tissue from the tree is exposed. As things progress, the canopy slowly gets smaller until it’s completely free of leaves. In any case, the average time it takes for an oak that’s sick to die is between five to six years. Nevertheless, it isn’t rare for some trees to last quite longer because of their resilient nature. Still, even these special oaks eventually pass away if humans don’t intervene and ease their condition. Experts have found the larval galleries of the buprestid beetle inside the lesions of trees that are sick. In addition to that, analysis of samples from decaying matter has proven that several types of bacteria are thriving there. Hence, many experts say that the acute oak decline is caused by stress caused by parasites and the bacteria which they carry. Despite that, scientists are still debating on what the actual cause of the problem is and why it’s killing off England’s oak trees. Consult a tree surgeon if you have any suspicions. Because the cause of the acute oak decline isn’t known, it sadly doesn’t have a cure. However, the Woodland Trust and other organisations have created a list of guidelines for people to follow if ever they encounter an affected tree. Furthermore, precautions have also been established to contain the issue and prevent it from spreading into other parts of the UK and beyond. After all, acute oak decline is aggressive and has the ability to effortlessly contaminate nearby specimens. Arborists are generally advised to avoid pruning afflicted trees as doing so makes the less able to withstand bacterial infections. Moreover, they also shouldn’t fell oaks when it’s wet outside as doing so increase the risk of spreading any pathogens. Aside from that, it is essential not to use any part of a felled specimens for recycling. Instead, the best option is to simply burn all the remains and then disinfect all the equipment that was used to cut the tree down. Fortunately, the acute oak decline hasn’t left Britain’s shores. Additionally, the Forest Research with funding from Defra has worked in collaboration with many scientists, universities, research organizations, and stakeholders to actively work on finding the exact cause of the natural phenomena in order to manage its spread and hopefully come up with an effective treatment for it. Thanks to that, people can look forward to a bright future where the oaks of England are no longer stricken with the “disease” which has already taken the lives of so many of them. One of the biggest issues that affects England’s forests and urban green spaces is the Dutch elm disease or simply DED. It exclusively affects elm trees is caused by a three species of ascomycete microfungi (Ophiostoma ulmi, Ophiostoma himal-ulmi, and Ophiostoma novo-ulmi) that propagates itself through bark beetles. The disease traces its roots to Asia where it unintentionally spread to Oceania, Europe and the Americas where it has drastically reduced the population of elm trees. In the UK alone, more than 60 million elms have been infected and killed by it according to the Woodland Trust. Hence, the affliction is a major problem that has the ability to upset the balance within any given ecosystem where any species of elm flourishes.
Fortunately, since elms are living beings, they also have a version of an immune system. As such, they can naturally fight the disease through camouflage or by producing chemicals which keep beetles away by making their bark distasteful for them. Moreover, the trees also employ numerous other methods to prevent themselves from succumbing to DED. Even so, human intervention is still often necessary to save a tree because of the aggressive nature of the condition. Dutch elm disease first introduces itself by withering away the leaves on an infected tree’s canopy during the summer months. Following that, the mentioned problem spreads downwards until large branches completely die. Soon enough, the roots start to decay because of the absence of nutrients that’s caused by the loss of leaves and important branches. Once that happens, it won’t be long before the infected tree succumbs to its illness and passes away. Nonetheless, a few species of elm don’t immediately fall to their demise once DED reaches their roots. Instead, they repeatedly put up suckers which thrive for about fifteen years before nature ultimately takes its course. Since the first outbreaks of the disease in America and Europe during the 20th century, arborists have come up with several measures to eradicate it and contain its spread. The first thing people did was to prune and burn the parts of the tree which were known to be infected. Sadly, the method didn’t gain popularity due to the fact that performing it was quite expensive. Chemicals were then soon employed to get rid of the disease. However, the substances which people used at the time proved to be harmful towards animals like birds that rely on elms. Thankfully, some effective and safe fungicides were invented as the years went by. In addition to that, advancements in technology by the University of Amsterdam has brought about a new vaccine called Dutch Trig which is exceptional at completely keeping healthy trees away from the disease. Nowadays, the Conservation Foundation has begun an active effort to propagate and distribute clones of the surviving indigenous elm trees in the UK. Because of that, the dwindled population of elms in the country is now slowly increasing once again. Despite that, it will probably take several decades before things return to normal as some areas still remain to be hotspots for DED. |
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