Research at Europe Regional Climate Center
Description of site
The Europe Regional Climate Centre (ERCC) is based at Wytham Woods, Oxfordshire, in the UK. The wood comprises a 400 hectare mosaic of semi-natural and plantation woodland, surrounded by copses, hedges, and individual trees. The ancient areas of woodland have been forested since prehistoric times and there has been an almost continuous record of settlement dating back to medieval times. The fragmentation of the forest and its effects on forest function and ecology are of particular interest to the scientists. The woods were donated to the University of Oxford 1943, and have been used for scientific study since that time.
Wytham Woods
Research partner institution and Principal Investigator
Earthwatch works with the Centre for Ecology and Hydrology, as well as the Environmental Change Institute and Wildlife Conservation Research Unit (WildCRU) at University of Oxford.
Volunteers from HSBC termed 'Climate Champions', assist with data collection in the field and data entry, overseen by the scientists.
The two principal investigators are Dr Eleanor Slade and Dr Terhi Riutti. Dr Eleanor Slade has a doctorate in tropical forest ecology from the Department of Zoology, University of Oxford. She studied the effects of selective logging on seedlings, herbivorous insects, and dung beetles in Sabah, Malaysian Borneo. Dr Terhi Riutta is a research assistant at Oxford University Centre of the Environment. Terhi completed her PhD with the Department of Forest Ecology at the University of Helsinki. Her research area is carbon dynamics in peatland ecosystems in changing climatic conditions. Terhi also completed her Master’s degree in Forest Sciences at the University of Finland.
Sampling design
Data collection methods are as described in the Introduction to HCP Research page
Work commenced in April 2008 and will continue to December 2011. There are ten permanent sampling plots situated within fragments of varying sizes. The default plot size is 1 ha (100m x 100m), but due to size and shape of some of the fragments, not all plots are uniform (Figure 2; Table 1). There is also a Smithsonian plot on the site, which is part of the CTFS network of sites, within which one of the ERCC plots is located.
Leaf litter is collected every two or three weeks during the leaf fall season (from mid-August until the end of December) and sporadically throughout the rest of the year. Leaf litter decomposition is also studied: leaf litter decomposition rates are assessed by burying mesh bags of leaf litter at several locations in each plot. Leaves from two species – ash and oak are used. Bags are of fine or large mesh, thus excluding or allowing entry of macro invertebrates, to assess their role in leaf litter decomposition. Replicate bags are buried and retrieved at three month intervals over a year. The weight loss of litter is then measured in the laboratory, and amounts of carbon and nitrogen present are analysed. Rate of leaf litter decomposition is thus studied, and the relative contribution of soil macro-invertebrates assessed. The decomposition of dead plant material is an important component of the carbon cycle.
This supporting research is being carried out at the China RCC using the same methods, with the difference that four types of leaf litter used.
Figure 2 Locations of plots at Wytham Woods. The Smithsonian plot is in the CTFS network of plots.
Table 1 Plot area, dimensions and number of leaf litter traps
In addition to study of vegetation, animals within the woods are also studied. Small mammals (e.g. mice, voles) are surveyed, as are moths, to understand their distribution within and between fragments of different sizes.
Data quality
Using volunteers means that data are collected by a large number of people, all learning new techniques. Assessing data quality is therefore essential. To this end, a number of trees were re-measured to understand the amount of error in measurements (fig 3). With the exception of one clear error, 1st and 2nd measurements were very similar to each other, with most measurements being within 1 mm of each other, and none more than 4 mm different.
Figure 3 Measurement uncertainty in tree diameter