Wetland plants thrive on River Nene after warm summer
A naturalist reports that wetland plants, including the vulnerable trifid bur-marigold, have prospered this year along the River Nene due to ideal
Wetland plants along the River Nene have flourished this year. The conditions have been ideal for species like the trifid bur-marigold, a plant now considered vulnerable in Great Britain.
After recent storms, the air by the river was fresh with scents of damp grass and blackberries. From a bridge over Ailsworth weir, the sound of water spilling over bright green swathes of river water-crowfoot was dominant. The main river flowed slowly and quietly.
A contrast of colors
The river margins were bright with flowers, creating a stark contrast to nearby scorched fields. Purple loosestrife, marsh woundwort, water mint, water forget-me-not and celery-leaved buttercup created a loose embroidery of mauve, blue and yellow. The standout was the trifid bur-marigold with its small, button-like golden flowers.
The plant's name comes from its mostly three-part leaves. Its fruits have barbed bristles, designed to hitch rides on passing animals or humans. It thrives in areas that flood in winter but are exposed in summer.
A vulnerable species finds a haven
Nationally, the trifid bur-marigold has declined due to drainage and canalisation of waterways. It is now listed as "vulnerable" in Great Britain. This year, however, it has prospered. Endless days of sunshine and warmth, combined with ready access to water, allowed for unusually lush growth.
As an annual species, it requires bare, damp mud in spring for its seeds to germinate. Along this stretch of the River Nene, Red Ruby Devon cattle have created that perfect habitat. Their trampling, or "poaching," of the soft river's edge opens up the necessary muddy ground.
The grazing management dilemma
Management that helps one species can trouble another. Too much cattle trampling erodes riverbanks and loosens silt, which can choke the clean gravels used by spawning fish. Yet fencing livestock out entirely allows vigorous perennial plants to take over the muddy margins, excluding the bur-marigold.
The Nene Park Trust, which owns the site, uses a simple gated fence set well back from the water. This system allows for measured doses of cattle grazing. It creates what the observer called a "Goldilocks arrangement", not too much disturbance and not too little, but just enough for the golden-flowered plant to maintain its riverside place.
