Woods In England Research Articles

The Carbon Cycle of a Maritime Ancient Temperate Broadleaved Woodland at Seasonal and Annual Scales

This study compares different approaches to quantifying the carbon cycle in a temperate deciduous forest at Wytham Woods in England, which is unusual in its maritime climate and mixed age structure, reflecting low levels of past management. We tested whether eddy covariance and biometric measurements gave consistent estimates of woodland productivity and ecosystem respiration at monthly and annual timescales. Biometric methods estimated gross primary productivity (GPP) as 22.0 ± 1.6 Mg C ha−1 y−1, close to the eddy covariance GPP value of 21.1 Mg C ha−1 y−1. Annual ecosystem respiration (R ECO) was similar, at 20.3 ± 1.5 Mg C ha−1 y−1 for biometric and 19.8 Mg C ha−1 y−1for eddy covariance. The seasonal cycle of monthly biometric and eddy covariance R ECO estimates also closely matched. Net primary productivity (NPP) was 7.0 ± 0.8 Mg C ha−1 y−1, 37% of which was allocated below ground. Leaf fluxes were the greatest component of NPP and R ECO. Ecosystem carbon-use efficiency (CUE = NPP/GPP) was 0.32 ± 0.04; low compared to many temperate broadleaved sites but close to values for old-growth sites. This may reflect the age of some trees, and/or the oceanic climate with relatively mild winters during which there can be substantial autotrophic maintenance respiration in winter but negligible growth. This study demonstrates that biometric measurements can provide robust estimates of site productivity and respiration and that eddy covariance and bottom-up measurements can be combined on seasonal and interannual timescales to enable a detailed understanding of the forest carbon cycle.

Competition between Quercus petraea and Carpinus betulus in an ancient wood in England: seedling survivorship

Abstract. Age structures of populations of canopy trees in Wormley Wood are consistent with reports that successional change is occurring, with Carpinus betulus replacing Quercus petraea as the dominant species. TWINSPAN analysis of data from a vegetation survey identifies three communities (described in earlier work), the ‘Bracken’, ‘Bramble’, and‘Bareground’ societies, characterized by increasing prominence of C. betulus and loss of species diversity.An experiment was set up in which C. betulus, Q. petraea and Betula pendula seedlings were explanted into each of the communities. Survival of seedlings was monitored over 860 days and differences investigated. Cohort survivorship differed between species and sites. C. betulus seedlings survived longer than Q. petraea in Bracken and Bramble communities.Species‐ and site‐specific variation in the types and effects of herbivory were found. Herbivory did not appear to be a critical factor in the survival of Q. petraea seedlings. The photosynthetic light response of the seedling species was measured in the field. The light compensation point for Q. petraea seedlings (77 μmol photon m‐2 s‐1) is higher than the maximum available light under the main tree canopies in the wood. In contrast, seedlings of C. betulus have a lower light compensation point (15 μmol photon m2 s‐1) and the mature tree casts a deeper shade than Q. petraea. It is suggested that the invasion of the canopy by C. betulus, following the cessation of coppicing, is creating light levels too low for Q. petraea seedling banks to persist.

Management of Roe Deer (Capreolus capreolus) in Small Deciduous Woods in England

Ecological research on a marked population of roe deer in Dorset between 1965–9 shows that the social behaviour of territorial bucks and adult does is an important factor in regulating the permanent breeding population. Most territorial bucks remain in the same territories for several years with little overlap between adjacent territories and their aggressive behaviour in April-August causes 1–3-year-old bucks without territories to emigrate. Adult does show similar site attachments but with considerable overlap between home ranges. Established does apparently prevent yearling does from remaining in the population but the mechanism involved is not known. Removal experiments show that non-territorial bucks replace territorial bucks and yearling does replace adult does. This indicates the presence of surplus animals which are prevented from establishing themselves by the behaviour of the territorial bucks and adult does. Management proposals and suggestions for future research are made. The present policy of the Forestry Commission to control fraying damage by shooting non-territorial bucks and leaving territorial bucks appears to be correct.