Weald Moors Trees

Trees were a peripheral part of the reed-dominated wetland of the Weald Moors past, limited to scrub habitat on the edge of the peatlands. Following widespread drainage in the early 1800s, the situation changed and large blocks of woodland, designed to shield newly-improved agricultural land from the elements, sprang-up across the moorlands. Consequently, some tree species are more characteristic of the area’s natural lineage than others… 

A Salix By Any Other Name: members of the Willow family (Salicaceae) share a preference for wetter soils, so it should be no surprise to learn they are an extremely common sight across the Weald Moors, frequenting damp places in many locations. Willows have a strong tendency to hybridise, which can make accurately identifying individual species problematic. However, a more generalised distinction can be made between those with broader leaves (which are known as ‘sallows’) and those with narrower leaves (known as ‘osiers’). The UK is home to two sallows, and both are present on the moorlands. Grey Willow (Salix cinerea) has a broad form and leaves that are twice as long as they are wide, distinguishing it from those of the Goat Willow (Salix caprea) — which has wider, wrinkly leaves with wavy margins and tips that bend to one side.

Both Grey and Goat willow have many alternative names, including ‘Pussy Willow’, a reference to the furry male catkins that appear on their twigs each spring. Willow species are unified by their tendency to flower before their leaves unfold, with female catkins appearing on separate trees. Consequently, they rely on wind and insect pollination for propagation, although they can also lower their branches to the ground in order to develop new roots vegetatively. While many willows are equally comfortable growing as a tree or a shrub, the White Willow (Salix alba), which is our largest native species, can reach a height of 25 metres — at a rate of two metres a year! Unsurprisingly, such rapid development has long given willow species a commercial value and you may still find them being grown on short rotation on arable farmland around the Weald Moors.

In common with other willows, the catkins of the Grey Willow (Salix cinerea) flower before the tree comes into leaf (Dan Wrench)

Populus Appeal: another characteristic group of wetland trees grown commercially on the Weald Moors are Poplars, which also belong to the Willow family. Sharing a similar preference for damp soils, species such as Aspen (Populus tremula) can form distinctive blocks of woodland. Their shimmering summer foliage (which turns orangey-red in autumn) provides an unmistakeable visual clue to identification that is usually accompanied by a characteristic dry rustling sound borne upon even the gentlest of breezes. The effect relies upon a high degree of flexibility near the leaf blade, which gives rise to the plant’s botanical name tremula, meaning ‘to tremble’.

A much scarcer species, found in just a few locations in the north of the moorlands, is Black Poplar (Populus nigra). Although it is now considered to be Britain’s rarest timber tree, Shropshire is one of a very few counties where significant populations can still be found. Robust, with wide rounded crowns and deeply furrowed dark grey bark, mature trees are typically found in isolated positions on open, boggy ground and do not tolerate dense shade. The presence of bare, moist soil is hugely important for this species because its distinctive fluffy, cotton-like seeds, which it produces in huge quantities, are short-lived and need to germinate within a couple of weeks. Sadly, there is a large disparity between male and female trees in the UK (the latter are denoted by green catkins, the former, red), which makes natural regeneration rare. The virulent Poplar Scab virus has also greatly diminished numbers of this tree, the seeds and early-flowering catkins of which are sought after by many birds and insects.

A poplar plantation on Crudgington Moor (Gordon Dickins)

Black Alder: along with Willow and Poplar, Black Alder (Alnus glutinosa) completes the trio of classic wetland trees found on the Weald Moors. Britain’s only native Alder species, it thrives on damp, acidic soils with a high water table, inhabiting woodland, marsh and the edges of watercourses. Its deep roots (which can extend to four metres) are particularly adept at mitigating flooding and can even grow in open water, forming masses of dark red cord that help support the banks of rivers and streams and prevent soil erosion. Soft and porous, its ability to withstand rot underwater once made it a commercially valuable source of timber for boats, mill wheels and sluice gates, while its racquet-shaped leaves and dark, deeply fissured bark (which is often covered in lichen) were traditionally used to make dyes.

If you’re getting the impression Alder is something of a super tree you’d be quite right because it is equally valuable for a wide range of wildlife, too. Not only is it the food plant of several moth species but a variety of sawflies, butterflies and craneflies also rely on it, and are among some 140 plant-eating insects associated with the tree. A member of the Birch family (Betulaceae), Alder is relatively short-lived — often surviving no more than sixty years — which makes it an attractive commercial woodland species. In this situation, many moisture loving lichens, mosses and fungi can become dependent on it, while its cone-like seeds (the empty cases of are a good pointer to identification in winter) are beloved of several finches, including Redpoll and Siskin. As we’ve already seen, Alder is a very common riverbank species. In times of flood, its dense roots can help shelter fish from the elements, while its fallen autumn foliage (which decomposes relatively quickly compared to other trees) also provides an important source of nutrients for riverflies and water beetles.

The distinctive cone-like seeds of Alder are a popular source of food for several finches, including Siskin and Redpoll (Dan Wrench)

On the Weald Moors: Willows, Poplars and Alders have been part of the Weald Moors landscape since time immemorial. This historical connection is commemorated in local place names such as Osierbed Covert, a reference to a tree colloquially known as Basket Willow, the radically pruned stems of which were once widely cultivated for the weaving of said item. Nowadays, Osier (Salix viminalis) is also planted for biomass but on the moorlands many wetland trees are afforded a much quieter existence. A walk along Kynnersley Drive offers many opportunities to see classic wetland species growing as both trees and shrubs in a range of situations, from scrub to woodland and on the margins of ponds, ditches and streams.

While you could come into contact with members of the Willow and Alder family just about anywhere on the Weald Moors the same cannot be said of Black Poplar, which I only found around Rodway and Tibberton Moor. The local situation is further confused by the presence of Lombardy Poplar, which is a cultivar (the product of selective breeding) of Black Poplar. However, whereas the latter is broad and spreading in form, the former appears more elegant and columnar.

A roadside willow on Crudgington Drive (Gordon Dickins)

A Pinsticker’s Guide! If this short introduction to the trees of the Weald Moors has whet your appetite for discovery, here is a more detailed (but not comprehensive) list of wetland plants recorded on the Moorlands:

Weald Moors Wetland Plant List (PDF)