5 research outputs found
ECOSSE: Estimating Carbon in Organic Soils - Sequestration and Emissions: Final Report
Background
Climate change, caused by greenhouse gas ( GHG) emissions, is one of the most serious threats facing our planet, and is of concern at both UK and devolved administration levels. Accurate predictions for the effects of changes in climate and land use on GHG emissions are vital for informing land use policy. Models which are currently used to predict differences in soil carbon (C) and nitrogen (N) caused by these changes, have been derived from those based on mineral soils or deep peat. None of these models is entirely satisfactory for describing what happens to organic soils following land-use change. Reports of Scottish GHG emissions have revealed that approximately 15% of Scotland's total emissions come from land use changes on Scotland's high carbon soils; the figure is much lower for Wales. It is therefore important to reduce the major uncertainty in assessing the carbon store and flux from land use change on organic soils, especially those which are too shallow to be deep peats but still contain a large reserve of C.
In order to predict the response of organic soils to external change we need to develop a model that reflects more accurately the conditions of these soils. The development of a model for organic soils will help to provide more accurate values of net change to soil C and N in response to changes in land use and climate and may be used to inform reporting to UKGHG inventories.
Whilst a few models have been developed to describe deep peat formation and turnover, none have so far been developed suitable for examining the impacts of land-use and climate change on the types of organic soils often subject to land-use change in Scotland and Wales. Organic soils subject to land-use change are often (but not exclusively) characterised by a shallower organic horizon than deep peats (e.g. organo-mineral soils such as peaty podzols and peaty gleys). The main aim of the model developed in this project was to simulate the impacts of land-use and climate change in these types of soils. The model is, a) be driven by commonly available meteorological data and soil descriptions, b) able to simulate and predict C and N turnover in organic soils, c) able to predict the impacts of land-use change and climate change on C and N stores in organic soils in Scotland and Wales.
In addition to developing the model, we have undertaken a number of other modelling exercises, literature searches, desk studies, data base exercises, and experimentation to answer a range of other questions associated with the responses of organic soils in Scotland and Wales to climate and land-use change.
Aims of the ECOSSE project
The aims of the study were:
To develop a new model of C and N dynamics that reflects conditions in organic soils in Scotland and Wales and predicts their likely responses to external factors
To identify the extent of soils that can be considered organic in Scotland and Wales and provide an estimate of the carbon contained within them
To predict the contribution of CO 2, nitrous oxide and methane emissions from organic soils in Scotland and Wales, and provide advice on how changes in land use and climate will affect the C and N balance
In order to fulfil these aims, the project was broken down into modules based on these objectives and the report uses that structure. The first aim is covered by module 2, the second aim by module 1, and the third aim by modules 3 to 8. Many of the modules are inter-linked.
Objectives of the ECOSSE project
The main objectives of the project were to:
Describe the distribution of organic soils in Scotland and Wales and provide an estimate of the C contained in them
Develop a model to simulate C and N cycling in organic soils and provide predictions as to how they will respond to land-use, management and climate change using elements of existing peat, mineral and forest soil models
Provide predictive statements on the effects of land-use and climate change on organic soils and the relationships to GHG emissions, including CO 2, nitrous oxide and methane.
Provide predictions on the effects of land use change and climate change on the release of Dissolved Organic Matter from organic soils
Provide estimates of C loss from scenarios of accelerated erosion of organic soils
Suggest best options for mitigating C and N loss from organic soils
Provide guidelines on the likely effects of changing land-use from grazing or semi-natural vegetation to forestry on C and N in organic soils
Use the land-use change data derived from the Countryside Surveys of Scotland and Wales to provide predictive estimates for changes to C and N balance in organic soils over time
Ethnic Speech and Ethnic Action as Ethnic Behavior: Part 1. Construction of the Brunel Ethnic Behavior Inventory
© 2016 Taylor & Francis.This article reports the construction of a new surveyâspecifically, the Brunel Ethnic Behavior Inventory (BEBI)âdesigned to measure ethnic speech and ethnic action as separate, yet related, aspects of individualsâ ethnic behavior. Using Tajfelâs social identity theory as a conceptual frame of reference, this study sought an answer to the research question of how many factors actually are measured by the BEBI, and tested the hypothesis that a two-factor model (i.e., Ethnic Speech and Ethnic Action as two correlated factors) would provide significantly better goodness of fit to the correlational data than would a one-factor model (i.e., Ethnic Behavior as one undifferentiated factor). Across one pilot sample (n = 101) and two main samples (n = 120 for Sample 1, n = 148 for Sample 2), the study found that not only did the BEBI measure two factors at most (i.e., Ethnic Speech and Ethnic Action) but, consistent with the hypothesis, the two-factor model yielded better goodness of fit than did the one-factor model. Implications for the conceptualization and measurement of Verkuytenâs âways of ethnicityâ are discussed
Estimating changes in Scottish soil carbon stocks using ECOSSE. II. Application
In order to predict the response of carbon (C)-rich soils to external change, models are
needed that accurately reflect the conditions of these soils. Here we present an example application
of the new Estimation of Carbon in Organic Soils â Sequestration and Emissions (ECOSSE) model to
estimate net change in soil C in response to changes in land use in Scotland. The ECOSSE estimate
of annual change in soil C stocks for Scotland between 2000 and 2009 is â810 ± 89 kt yrâ1, equivalent
to 0.037 ± 0.004% yrâ1. Increasing the area of land-use change from arable to grass has the greatest
potential to sequester soil C, and reducing the area of change from grass to arable has the greatest
potential to reduce losses of soil C. Across Scotland, simulated changes in soil C from C-rich soils
(C content >6%) between 1950 and 2009 is â63 Mt, compared with â35 Mt from non-C-rich mineral
soils; losses from C-rich soils between 2000 and 2009 make up 64% of the total soil C losses. One
mitigation option that could be used in upland soils to achieve zero net loss of C from Scottish soils
is to stop conversion of semi-natural land to grassland and increase conversion of grassland to seminatural
land by 125% relative to the present rate. Mitigation options involving forestry are not
included here because the data available to calculate losses of soil C do not account for losses of soil C on drainage of semi-natural lan
Estimating changes in Scottish soil carbon stocks using ECOSSE. I. Model description and uncertainties
To predict the response of C-rich soils to external change, models are needed that accurately
reflect the conditions of these soils. Estimation of Carbon in Organic SoilsâSequestration and
Emissions (ECOSSE) is a model that allows simulations of soil C and N turnover in both mineral and
organic soils using only the limited meteorological, land-use and soil data that is available at the
national scale. Because it is able to function at field as well as national scales if appropriate input data
are used, field-scale evaluations can be used to determine uncertainty in national simulations. Here
we present an evaluation of the uncertainty expected in national-scale simulations of Scotland, using
data from the National Soil Inventory of Scotland. This data set provides measurements of C change
for the range of soils, climates and land-use types found across Scotland. The simulated values show
a high degree of association with the measurements in both total C and change in C content of the
soil. Over all sites where land-use change occurred, the average deviation between the simulated
and measured values of percentage change in soil C was less than the experimental error (11% simulation
error, 53% measurement error). This suggests that the uncertainty in the national-scale simulations
will be ~11%. Only a small bias in the simulations was observed compared to the measured
values, suggesting that a small underestimate of the change in soil C should be expected at the
national scale (â4%