Effects of agri-environmental habitat provision on winter and breeding season abundance of farmland birds

Farmland bird populations continue to show declines in spite of over 20 years of research and implementation of agri-environmental schemes (AES) intended to reverse this. Although it is well known that provision of winter food resources can attract farmland birds, there is continuing uncertainty over the ability of AES to provide tangible benefits for target species in terms of increased abundance. Answering these questions is hampered by interannual fluctuations in bird populations and the mobility and territoriality of farmland birds, which have complicated the interpretation of previous studies. We monitored birds for five years on a large arable estate in central England managed under varying levels of AES uptake (low level uptake of simple and widely applicable AES options, more extensive uptake of more complex AES options), and two control treatments (on-site and off-site). Bird abundance in winter and both total abundance and number of territories in the breeding season were calculated from monthly visits to 16 transects. Several species showed significantly higher winter abundance on AES treatments, particularly granivorous species (e.g. reed bunting, yellowhammer, linnet). Many other species (e.g. blackbird, chaffinch, robin) also showed significant differences in winter abundance between treatments on the estate and off-site controls. In the breeding season, linnet, reed bunting, goldfinch and combined granivorous birds showed higher abundance or number of territories on AES treatments compared to on-site controls. For most other species the differences were only significant between treatments on the estate and off-site controls. Independently of AES treatment, a lower coverage of cereals or greater Shannon diversity of crops in the local landscape also had a positive effect on the abundance of many species. Our results suggest that well-implemented AES can significantly enhance local populations of both farmland specialists of conservation concern and generalist species. Our results also show that, in many cases, these effects were only demonstrable at the farm scale, in comparison with off-site controls. This is probably due to high levels of movement and dispersal of birds resulting in a farm-scale spill-over of beneficial effects of agri-environment measures. Our results therefore highlight the importance of thinking beyond the single-farm scale when designing schemes or studies for monitoring the effectiveness of AES, and the importance of selecting appropriately located controls

On the Non-Existence of Optimal Solutions and the Occurrence of “Degeneracy” in the CANDECOMP/PARAFAC Model

The CANDECOMP/PARAFAC (CP) model decomposes a three-way array into a prespecified number of R factors and a residual array by minimizing the sum of squares of the latter. It is well known that an optimal solution for CP need not exist. We show that if an optimal CP solution does not exist, then any sequence of CP factors monotonically decreasing the CP criterion value to its infimum will exhibit the features of a so-called “degeneracy”. That is, the parameter matrices become nearly rank deficient and the Euclidean norm of some factors tends to infinity. We also show that the CP criterion function does attain its infimum if one of the parameter matrices is constrained to be column-wise orthonormal

Developing an indicator of the abundance, extent and impact of invasive non-native species. Final report

This report describes an indicator of the abundance, extent and impact of invasive non-native species in Great Britain. The main ideas and options for the abundance indicator and for the impact indicator are considered. A third type of indicator, the annual rate of establishment of new non-native species, is outlined, with provisional data presented only for England. Most of the options for the abundance indicator do not in fact measure abundance, but use either frequency in samples or frequency in recording scheme data as a substitute. An exception is the Breeding Bird Survey, for which numbers of individuals are counted. Several well-recorded groups of organisms have no non-native species (e.g. butterflies and lichens) or exceedingly few non-native species (macro-moths). Datasets selected for the abundance indicator were the Breeding Bird Survey (birds and mammals), Countryside Survey (vascular plants), British Bryological Society data (bryophytes) and Marine Biological Society data (marine organisms). From samples of records in each species group, the non-native component was calculated as proportion of all species sampled. This provided a temporal trend in non-native proportions, which were calculated separately for England, Scotland and Wales. The GB trend was derived by combining the trends for each component country, weighted by the area of each. Finally, the overall trend was calculated as a weighted geometric mean of trends for each species group, converted to an index by dividing by a constant to start at 1 in the baseline year 1990. The weights applied were birds 20%, mammals 20%, vascular plants 30%, bryophytes 10% and marine organisms 20%. There were no suitable datasets from the freshwater environment. No direct measure of impact could feasibly be calculated for all invasive species in Great Britain. As a substitute, an indicator based on the extent of occupation by invasive species was adopted. The methodology for the indicator was based on a scheme developed by the Belgian Forum on Invasive Species. First, a list of the most invasive species was compiled, using a simplified environmental impact assessment protocol to assign species to threat categories. Then the extent of each invasive species was scored for 1960, 1970, 1980, 1990, 2000 and 2007, on a 5-point scale ranging from 0 (absent) to 4 (present in more than half the territory). Extent scores were added to obtain the indicator. Over the period 1990-2007, the mean indexed proportion of records of non-native species in samples of birds, mammals, plants and marine life rose by 23%. Except for mammals, the absolute proportion was still only about 1% of the total. The assessment protocol assigned 49 species in Great Britain to the highest threat category. There were 3 marine plants, 16 marine animals, 4 freshwater plants, 8 freshwater animals, 8 terrestrial plants and 10 terrestrial animals. Over the period 1990-2007, the summed extent scores of these invasive non-native species rose by 40%. The increase of invasive species was particularly large in the freshwater and marine environments. Although non-native species are a potential threat, they are still only a small proportion of the animals and plants to be found in most of the land area and coasts of Great Britain. Vertebrates stand out as the most invasive group. For all groups of organisms reported here, England was the country most affected by non-native species. Scotland was the least affected. Wales was intermediate. In 2008, values of the impact indicator for the three countries were respectively 135, 73 and 95. Most species groups showed a trend over time towards an increasingly non-native biota. If the indicator is to be developed further, the main priority is to include freshwater species in the abundance component. Because the list of invasive species depends on expert judgement, it needs to be reviewed and if necessary updated at regular intervals. Further analytical work is desirable, to improve the signal obtained from recording scheme data

Arctic Operations Handbook: Generic Framework for Environmental Assessments

The Dutch offshore industry has the ambition to execute operations on a large scale in Arctic areas, for instance for installation and operation of oil- and gas production facilities and pipelines. Currently, there is no standard for safe operations by service companies in Arctic offshore areas. Therefore a Joint Industry Project (JIP) was started to carry out the necessary investigations to enable the formulation of guidelines for Arctic operations. One of the deliverables of the JIP is an environmental assessment pilot

Arctic Operations Handbook: Generic Framework for Environmental Assessments

The Dutch offshore industry has the ambition to execute operations on a large scale in Arctic areas, for instance for installation and operation of oil- and gas production facilities and pipelines. Currently, there is no standard for safe operations by service companies in Arctic offshore areas. Therefore a Joint Industry Project (JIP) was started to carry out the necessary investigations to enable the formulation of guidelines for Arctic operations. One of the deliverables of the JIP is an environmental assessment pilot

Spatial pricing models with lumpy transportation costs: the case for travel cost subsidization

Spatial pricing, Shopping trip, D42, R10, L1,