EXEC’S CORNER

Welcome to the December issue of ECT’s quarterly newsletter, at the end of another ‘interesting’ year for all sorts of reasons. It has been a fairly momentous quarter for the charity, seeing the exciting beginnings of our careful remit expansion to include certain types of long-term monitoring (LTM) studies. In October, ECT’s Board of Trustees registered our first three new LTM-LTE ‘hubs’ which link up eligible, professionally-run LTMs with existing long-term experiments (LTEs) on our register. It is our hope that this will help to safeguard vulnerable LTMs, add ‘scale’ to experimental studies and promote closer collaboration between monitoring and experimentation. The first three hubs have been established around the MOORCO LTE in Scotland, Park Grass in Hertfordshire and the North Wyke Farm Platform in Devon. The LTMs that have been linked up will become eligible for ECT’s Small Grants scheme one year after registration. Look out for a new LTM-LTE hubs section on our website soon.

This quarter has also seen the establishment of two new important ECT partnerships with the British Society of Soil Science and the Royal Society of Biology. On behalf of staff and trustees here at ECT, I wish you all an enjoyable festive season!

- Ben Sykes.

WEBINARS

SMALL GRANTS AWARDED

ECT is pleased to have awarded a data curation grant to David Gowing from Open University for vital work to secure the long-term survey data from the Somerford Mead LTE in Oxfordshire. The data will be deposited in NERC’s Environmental Information Data Centre and so available to all. A small grant has also been awarded to Caroline Meharg at Queen’s University Belfast towards the costs of surveying the soil rhizosphere microbes at the Hillsborough LTE in Northen Ireland. Read more about our Small Grants scheme.

BLOG FOR THE ECT

Do you want to write a blog for the ECT? The ECT welcomes blog pieces to add to our collection. If you have worked at an LTE site, or you have supported one in the past, or perhaps you feel passionate about a topic that affects LTEs, then get in touch by e-mailing Danae to express your interest, and your topic. You can see past blogs on the ECT blog page. 

VOLUNTEER FOR THE ECT: A REMINDER

The ECT has begun establishing a pool of volunteers that can be called upon from time-to time to help with various projects. Volunteer opportunities may include remote communications activities or, depending upon pandemic restrictions and your locality, joining a maintenance team for a day at one of the active long-term experiments on ECT’s register. Depending upon the size of the volunteer pool and availability, we expect to call upon volunteers up to twice a year. If you are interested in joining this volunteer pool, please e-mail Ben to express your interest, and include a short paragraph describing any relevant skills/knowledge that you may bring to the role.

ECOLOGY ACROSS BORDERS 2021 CONFERENCE IN LIVERPOOL

The ECT will be attending the upcoming British Ecological Society conference: Ecology Across Borders this month in Liverpool from 12-15 December. All conference delegates are invited to stop by the ECT exhibition booth at stand number 12 and meet ECT staff/learn more about the charity.

PHD OPPORTUNITY AT THE OPEN UNIVERSITY

PhD Project: Hyperspectral signals of change in grassland ecosystems

Principal Investigator: Kadmiel Maseyk (The Open University)

Co-supervisors: Clare Lawson (Open University), Holly Croft (University of Sheffield)

Application deadline: 12pm, Friday 7 January 2022

This project will investigate ecosystem responses to environmental change and the associated reflectance spectra in grassland ecosystems. It will focus on the impacts of hydrological change (drier and wetter) on calcareous grassland at the RainDrop LTE, located in a Natural England SSSI at Wytham, Oxfordshire. You will gain experience in field spectroscopy and plant ecophysiological and measurements, data handling and analysis. You will also be supported in the development of your skills in field planning and project management, and there is possibility of a CASE partnership with Natural England. Students are invited to apply for this PhD with a strong background in plant, ecosystem ecology or grassland ecology, physiology or remote sensing, and an interest in global change processes. A clean driving licence for accessing UK field sites is desirable.

BIFoR-FACE MEDIA

In October, some of the first results from the BIFoR-FACE experiment (University of Birmingham) have emerged from Rob MacKenzie’s PhD student Anna Gardner. Her work, which shows that oak trees increase their rate of photosynthesis as a result of climate change has made it into The Times and the Daily Mail. Anna Gardner and Jeremy Pritchard were also featured in the BBC Midlands Today broadcast clip Treetop update on climate change. Their journal paper is in Tree Physiology and is open access. Later in the same month, BIFoR-FACE worked with We Are Spoke to produce a 5-minute explainer video on the experiment.

BAMFORD AND HORDRON EDGE LTEs CONCLUDE RESEARCH

The bracken control/grass-moor revegetation experiments at Hordron Edge and Bamford Edge in Derbyshire, managed by Rob Marrs, are being decommissioned in a planned finish, having reached the end of their useful lives.

The Hordron Edge experiment was originally part of a series of seven comparable experiments set up on a three-year Defra contract comparing six bracken-control treatments and various restoration techniques. They covered a reasonable geographic range: From Cheviot in the north to Cannock Chase in the South, and from the Carneddau mountains in the west to the Peak District in the east. Defra continued funding until 2007, allowing an eighth experiment to be added in 2004 in the Peak District. However, after 2007, the Cannock Chase and Carneddau experiments fell by the wayside. Nonetheless, Rob Marrs and his team have maintained an interest in the Sourhope experiments, and kept both Peak District experiments going. Two on Cheviot were re-sampled for the last time in 2019, and the two Peak District experiments came to a natural conclusion in 2021. The Hordron Edge site was the last one to finish after 28 years. Set up in 1993, it was always the study’s flagship experiment.

The Hordron Edge experiment tested six bracken control treatments. Each treatment had a sheep-grazed and an ungrazed plot coupled with three heathland restoration treatments. Monitoring continued from 1993 through to 2021 with a break in 2020 due to COVID-19. The experiment was stopped to allow Rob Marrs to undertake substantive destructive harvests which meant destroying the underlying vegetation thus making assessments of future species change invalid. There had been considerable tree invasion into some plots where sheep grazing had been prevented and the vegetation was moving towards a woodland. This is the sort of change that might be expected in upland (re)-wilding schemes, which are one of the suggested strategies for increasing carbon capture. Rob Marrs teamed up with Carly Stevens (Lancaster University) and her PhD student David Watts (after Rob Marr’s ECT webinar in 2020) to measure the growth and carbon capture of these trees. Luckily, David is a qualified tree surgeon and during October, he and his fellow tree surgeons harvested all the trees (n=60), cutting them into sections and weighing them before sending samples for carbon and nitrogen analysis. See the last tree falling in this video (Credit: David Watts).

This study will hopefully provide useful data on rewilding, and the amounts of carbon that can be captured by developing natural tree invasion. Part of this study involved assessing the amount of carbon and nitrogen in the bracken. It also involved the mammoth task of sampling the underground bracken rhizomes: 48 rhizome pits were dug, each of 50 cm x 50 cm x ca. 40 cm depth. To put this in perspective, this equates to digging almost 5m³ or 10 tonnes of soil, all of which had to be hand-sorted to extract the rhizomes. The last pit dug is shown below, along with its hard-won rhizomes and as Rob Marrs describes himself: an aged Emeritus Professor who is standing up straight and pretending his back and legs don’t hurt!

The other Peak District experiment at Bamford Edge started in 2004 to compare the effectiveness of three bracken control methods: bracken cutting, and herbicide treatments (which are recommended), and bracken bruising - an old but resurrected method. Treatments were applied from 2004–2012. Bruising was ineffectual but the cutting and herbicide treatments produced excellent results. After 2012, the bracken was allowed to recover. The vegetation was monitored every year except for 2020 due to COVID-19. The experiment was stopped for two reasons. Firstly, bracken recovery can now be monitored using satellite imagery, and secondly because a new walkers’ access point for tourists and climbers had been created.

These experiments have produced a lot of data for improving bracken control methods, and restoring vegetation with a greater conservation value. They have also yielded data for testing ecological hypotheses, and acted as a vehicle for other studies (soils, seed banks etc). The data have been included in three international databases, have contributed to the national bracken control guidelines, and used in a University of Liverpool impact case study.

Rob Marrs would like to thank the Moscar Estate landowners (previously Mr Jeremy Archdale, and more recently the Duke and Duchess of Rutland); the gamekeepers (Stephen Lloyd and Jason Clamp) and grazing tenant (Neill Taylor); Defra, the ECT, the Heather Trust, the Leverhulme Trust, BayerCrop Science and United Phosphorus.

A NEW ADDITION TO THE MOORHOUSE GRAZING EXPERIMENTS

A ‘new’ set of experiments testing the effects of grazing removal relative to background sheep grazing pressures at Moor House in Upper Teesdale were added to ECT’s national reigster earlier this year by Rob Marrs (University of Liverpool). These experiments encompass a range of plant communities found in upland Britain. Set up between 1953-67, they test the long-term effects of the removal of sheep grazing (exclosure) relative to an ungrazed “control”. The four plant communities and the sites are:

1) Hard Hill Summit, Little Dun Fell and Knock Fell: High-level grasslands with three replicate sites which are dominated by Agrostis capillaris and Festuca species, and are on brown-earth soils on the summit ridges.

2) Cottage Hill and River Tees: Intermediate grasslands with two replicate sites originally dominated by Eriophorum vaginatum and Nardus stricta respectively.

3) Four blanket bog sites (aside from the others which are embedded in the Hard Hill Grazing and Burning Experiment) all with various altitudes.

4) Silverband and Troutbeck Head: High-level bogs at 685 m.

The plots are monitored on decadal intervals as upland community change is very slow. A point-quadrat approach is used (Marrs et al., 1986). All the data collected so far are available in the open-access UKCEH databases (Rose et al., 2018, 2020). These experiments have until recently been considered as unreplicated ones highlighting that no statistical inferences could realistically be drawn from the data. However, a recent meta-analysis of these experiments showed clear groupings (as noted above) between sites (Milligan et al., 2016; Alday et al., 2021). Upon reviewing the start and monitoring dates, the individual sites (as grouped above) made experimental sense with the constituent sites being able to be considered as replicates. It is unknown how much thought went into this planning when these studies were set up. So far monitoring has been conducted by former Nature Conservancy Council staff (1953-1982), Rob Marrs (1982-92), and the Environmental Change Network Team - John Adamson, Rob Rose and John O’Reilly (1992-present) along with countless helpers. Natural England have agreed to organise future monitoring, and any new data will be added to the existing UKCEH databases. There is a further unreplicated site at Moss Burn (Johnny’s Flush) which had a substantial population of the “vulnerable” Saxifraga hirculus. The effects of sheep grazing versus no sheep grazing was assessed between 1973 and 2013. The gates to the exclosure were subsequently removed as the S. hirculus was deemed to be threatened. For more on this experiment, see Rose et al. (2020).

GLEN FINGLAS LTE

It has been a quiet year at Glen Finglas LTE for Robin Pakeman and his team at the James Hutton Institute, with just the routine bird and vegetation structure monitoring taking place. However, the team has continued to innovate, flying a drone over the plots for the first time. The drone flights were high enough not to disturb the meadow pipits and allowed observation of the vegetation structure at the same time as the birds were choosing territories and nest sites. 

The team has also continued to publish some of the vegetation work and have a new open access paper out in Biodiversity and Conservation. Removal of grazing had the highest impact on species replacement, whilst increased grazing was closest to maintaining the original species complement. Wet heath and Molina mire had the lowest turnover in species, whilst Agrostis-Festuca and Nardus grasslands displayed the highest, which reflects their more dynamic vegetation. However, the increased offtake associated with increased grazing led to a degree of homogenisation as grazing tolerant species associated with preferred communities increased in the unpreferred ones. Decisions about grazing management must include potential trade-offs between stability and homogenisation.