Why Do We Need To Graze Nature Reserves, And Why Don’t We Just Let Nature Do It’s Own Thing?

 

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Tulip, her calf and Jill’s calf in front, keep their eyes peeled.

The next job for the cattle when they’ve finished with the south marsh entrance section is grazing the Tenant Farmer’s Field (3.2 acres), which nestles nicely between the Rhombus Field (4 acres) and the River Stour, to the west, flowing north to south on its way through the nearby town of Stourport on Severn, a couple of miles downstream, and into the River Severn immediately south of it. The east side of the Rhombus Field is bordered by the mainly wet non-intervention Middle Wood (4.5 acres). The Tenant Farmer’s Field is a mixture of damp and wet grassland. The Rhombus Field is soaking wet with a small amount of damp hardstanding at its northern end; its waters flow into the south marsh central drainage ditch and out into the River Stour via the South Pool and the main sluice.

Yesterday, I took a walk around the Tenant Farmer’s Field and the Rhombus Field. The Rhombus Field was grazed for eleven days in September; it’s a little wetter now, but I managed to walk it all without filling my wellies with water. Grass is sprouting from the small areas of poaching, and the field will benefit from further grazing now. I’ll leave the gate between the Tenant Farmer’s and the Rhombus Fields open for the cattle to wander back and forth.

I disturbed three snipe at different times when trudging through the Rhombus Field; they flush earlier than the rarer Jack snipe, which stay put until almost stepped upon. The birds zigzagged their way into the Tenant Farmer’s Field, alarm calling as they went.

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The new corridor linking the Riverside and Hoo Brook Pastures to the Swamp and the Northern corridor. The Swamp is on the left and Hoo Brook the right. The red tractor is in the Riverside Pasture. This photograph is shot from inside Hoo Pasture.

The new corridor and reinstatement of Hoo Brook and Riverside Pasture stock fencing is complete, courtesy of Western Power. A new gate will be installed to access the Swamp.

This northern area of the marsh looks tame and bare now, but a couple of years ago the vegetation in this area was thick and two to three metres high. Look here to see what it was like during 2015, the first year of grazing.

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The GCN (Great Crested Newt Pond) at the north east corner of the swamp, across the ramp from Hoo Pasture gate.

This is the great crested newt pond. It’s one of many ponds and scrapes on Wilden Marsh that are home to this rare and protected newt, but for many years it has been completely shaded by a sprawling willow coppice. The pond now needs to be cleared of brash; the pond clearance work, that is to be carried out between now and late January, will  help the pond to flourish next growing season. We are looking into the possibility of raising water levels along Hoo Brook SSSI to help with its rewetting.

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Hoo Brook flowing west to the River Stour. The red tractor is on the bank of the River Stour.

This is Hoo Brook after the coppicing. On the right behind the chain link fence is the current sewage pumping station, built on the site of the historic Falling Sands Rolling Mills and Iron works.

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The Conjunction of Hoo Brook with the River Severn. To the left is a blockage which will soon be removed.

The blockage at the River Stour/Hoo Brook confluence will be removed, and the work around the Hoo Brook end of the marsh will soon be finished. In the mid to late 1700s there was a rolling mill and iron works at this water intersection that used two 15 feet wide overshot and breast waterwheels connected together to drive two rolling mills and metal shears. A few metres upstream of the blockage is the historic wall I posted about recently (Click here to go to that post).

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Burning willow stumps in Hoo Wood Pasture.

Three large willow trees have been coppiced just inside Hoo Brook Pasture gate; to stop them regrowing and blocking the entrance, I’ve lit brash fires over them to destroy the dormant buds in the live bark and any lignotuberous buds near the junction of the root and stem/trunk.

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New drinking water hole in Hoo Brook Pasture.

The Hoo Brook Pasture doesn’t have a reliable source of drinking water for the cattle, so I’ve dug down into the water table to provide a short term water source close to the gate. The water hole will cater for those times when we want to restrict the cattle to the pasture for a day or two. Even if the cattle are shut in overnight, they need access to a source of drinking water. Cattle can drink 30 to 40 litres/day– around 500 litres daily for the Wilden Marsh herd. If I need more water, I can increase the size of the hole.

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Hidden concrete bridge across Hoo Brook. This bridge will be the cattle’s route to the new wildlife area.

A new wildlife area is in the process of being created north of Hoo Brook, and the marsh cattle will be grazing it. the area will be planted with wild flowers and bat boxes and a concrete otter holt will also be installed. Access to the wildlife area for the cattle will be over this hidden concrete bridge, which is a relic of our distant industrial past. A 8 foot gate will be installed in this fence.

I’m on the marsh in darkness most days at this time of year, and bats constantly zoom around my head. So there might be a big demand for bat houses on Wilden Marsh and especially in the new wildlife area.

So, why do we need to graze nature reserves, and why can’t we just let nature do its own thing?

Well, we don’t need to graze nature reserves, we can mow or flail them, but the best method of managing a reserve like Wilden Marsh is with cattle.

Let’s look at some of the pros and cons of using mowing, flailing and cattle on a marsh site:

MOWING AND FLAILING:

  1. Mechanical mowing and flailing can be used and has been used on the marsh, at least it has on the fields that are firm enough to support the machinery, but these are brutal ways of controlling weeds, and they rarely achieve satisfactory results in terms of maximising conservation effort. The best that can be said of them is that they are relatively quick and efficient methods of reducing vegetation height.
  2. After use the equipment can be stored away and forgotten about until the next time it’s needed. They are also non selective and cut everything in front of them.
  3. Many of the fields on Wilden Marsh are too wet to mow or flail.

CATTLE GRAZING:

  1. Cattle are selective browsers that eat palatable vegetation first. Once the tasty bits have been grazed the cattle will move onto tougher and less palatable vegetation. So there is an element of useful control over what and when areas are grazed.
  2. Cattle can handle the roughest, wettest and coldest weather and ground conditions.
  3. They trample vegetation into the soil without compacting it unduly.
  4. They knock down vegetation.
  5. They fertilise the ground with their dung.
  6. They don’t interfere too much with important marsh habitats nor the health of rare fauna and flora.
  7. Cattle use their tongues to wrap around and pull up tufts of vegetation, leaving uneven sward lengths and producing a tussocky field. They will eat longer, coarser grasses and push their way through scrub and bracken to create open spaces.

The drawbacks of using cattle are:

These are only drawbacks for those not keen on working with cattle.

Cattle need to be physically checked at least once each day and moved from field to field as necessary.

Infrastructure such a stock fencing, gates, sufficient quantities of drinking water and the means of delivering it to the cattle, corrals, a crush and a cattle trailer should be provided. TB testing must be carried out once each year, animals must be tagging and recording, and the occasional services of a vet will be required, and there are administrative aspects to consider.

So why bother? Why not leave nature to do its own thing?

Well, if the marsh is left to its own devices it will very quickly turn into a thick willow, birch and alder forest within ten years. There is an area of extremely dense willow, birch and alder wood land in the Lagoon Field that proves my point entirely, Leaving nature to do its own thing really isn’t an overall option; we do have a couple of non-intervention areas on the reserve, but our aim is to maintain the marsh in a lively and vital condition

What we shouldn’t forget is that many years ago, people cleared the land of trees to form open spaces for farming. Their grazing animals helped to shape many of our semi-natural habitats, which developed rich and diverse wildlife communities. Our grassland, marshes and meadows, moorland and heathland habitats were all shaped by human activity; grazing is often the most effective and sustainable way to maintain them and their huge variety of plants and animals.

I am a firm believer that if a nature area within an urban setting is neither maintained nor appreciated, it is highly likely to be transformed into an industrial or residential estate.

So grazing progressively reduces the volume of marsh vegetation during the growing season, including nettles and notifiable weeds such as thistles. Fortunately, cattle won’t knowingly eat poisonous plants such as ragwort and hemlock. From September to April, the cattle graze the vegetation as short as possible so that the spring sunshine can work its magic on the early emerging plants at the start of the growing season. Compartment grazing helps ensure that individual fields and pastures can be grazed at the right time and to a suitable extent to suit their intended use or the plants that grow there. As an example, the reed beds of South Riverside Pasture have been, and Rhombus Field can be, grazed to achieve ground cover and conditions that might attract wading birds.

I think cattle can be extremely important and versatile marsh conservation management tools, and like all quality tools they have to be used carefully, intelligently and maintained in good order if they are to achieve quality results.

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4 Responses to Why Do We Need To Graze Nature Reserves, And Why Don’t We Just Let Nature Do It’s Own Thing?

  1. ramblingratz says:

    All very interesting, plus it is just nice to have cattle around 😉

    Liked by 1 person

  2. Mike Griffiths says:

    There is always something sinking into Wilden Marsh, Ratty.

    Like

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