Analysis of Andean blackberry (Rubus glaucus) production models obtained by means of artificial neural networks exploiting information collected by small-scale growers in Colombia and publicly available meteorological data

The Andean blackberry (Rubus glaucus) is an important source of income in hillside regions of Colombia. However, growers have little reliable information on the factors that affect the development and yield of the crop, and therefore there is a dearth of information on how to effectively manage the crop. Site specific information recorded by small-scale producers of the Andean blackberry on their production systems and soils coupled with publicly available meteorological data was used to develop models of such production systems. Multilayer perceptrons and Self-Organizing Maps were used as computational models in the identification and visualization of the most important variables for modeling the production of Andean blackberry. Artificial neural networks were trained with information from 20 sites in Colombia where the Andean blackberry is cultivated. Multilayer perceptrons predicted with a reasonable degree of accuracy the production response of the crop. The soil depth, the average temperature, external drainage, and the accumulated precipitation of the first month before harvest were critical determinants of productivity. A proxy variable of location was used to describe overall differences in management between farmers groups. The use of this proxy indicated that, even under essentially similar environmental conditions, large differences in production could be assigned to management effects. The information obtained can be used to determine sites that are suitable for Andean blackberry production, and to transfer of management practices from sites of high productivity to sites with similar environmental conditions which currently have lower levels of productivity.     

Ecosystem-based management in the Great Bear Rainforest

Ecosystem-based management is the management system being applied to 6.4 million hectares of the coast of British Columbia, Canada, an area referred to as the Great Bear Rainforest. This approach, intended to manage for ecosystem integrity and community wellbeing, is similar in many respects to ecosystem management approaches elsewhere. However, several novel elements are involved in application of ecosystem-based management on British Columbia's coast: shifts in power that have led to increased aboriginal control and the formation of coalitions between groups that were formerly in opposition; development of explicit models relating management strategies to land-use objectives and separating knowledge from values; use of ecological thresholds and natural variability to establish management targets. Current management is based on transitional targets that differ from science-based targets. Many challenges remain in moving to full implementation of ecosystem-based management, including the difficulties involved in moving from one management model to a fundamentally different one, limited resources for implementation, dealing with complex systems, the lack of freely available multi-disciplinary data, and the difficulty of bringing concepts of uncertainty and risk into public policy discussions in a transparent manner.     

Genetic considerations in transfers and introductions of scallops

As the potential of scallop aquaculture becomes increasinglyrealised, transfers (movement within a species' range) andintroductions (movement outside a species' range) of scallops arebecoming more common. To predict the genetic consequences oftransfers, information on genetic differences between source andrecipient populations is vital. Morphological, allozyme and DNAbased data on genetic differentiation of scallop populations andscallop sub-species are presented and discussed. Otherconsiderations are the numbers of individuals transferred andwhether they are wild stock or hatchery product. Loss of geneticdiversity is difficult to avoid in hatchery conditions althoughthere are ecological advantages to using disease-free hatcheryseed. Mitochondrial DNA data indicating significant geneticconsequences of the introduction of Argopecten irradians fromthe USA to China are discussed and compared with data onPatinopecten yessoensis introduced from Japan to Canada.Potential risks and consequences of hybridisation should beexperimentally assessed before introductions of scallops arecarried out. Hybridisation is unpredictable and can lead to lossof genetic diversity or breakdown of co-adapted gene complexes.The use of sterile triploid scallops for introductions to avoid hybridisation and reduce ecological impact has merit butreversion to diploidy may occur.     

Evaluating the efficacy of small‐scale marine protected areas for preserving reef health: A case study applying emerging monitoring technology

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Plant development and yield components under a tropical environment in soybean cultivars with temperate and tropical origins

Cultivar tests under tropical environments could be an approach to explore soybean productivity under high temperature. Twenty-nine soybean cultivars divided into five groups with temperate origin (Japanese and US) and tropical origin (Indonesian-old, Indonesian-modern and other tropical) were grown for two years in a tropical environment at Banten, Indonesia, with minimal season-to-season variation in air temperature and day-length. Temperate cultivars were earlier in flowering and shorter in duration from R1 to R5. Temperate cultivars had a seed yield of 157 g m^?2 (mean temperate cultivars) compared to 249 g m^?2 (tropical cultivars), which was due to having lower values of pods, seed number and TDW. In addition, the occurrence of shriveling and smaller seed size compared to plants grown in their region of origin was considerably evident in Japanese cultivars. To account for the difference of growth duration, a maturity-corrected index for yield and relevant variables was calculated to consider the amount of incident solar radiation. The yield index for all tested cultivars ranged from .49 to 1.48, and Japanese cultivars showed the lowest yield index (.67), followed by US cultivars (.87), whereas tropical cultivars had index means from 1.05 to 1.20. Although they were both of temperate origin, Japanese cultivars tended to show a lower index than US cultivars. The tendency was similar for TDW and node number. The poor performance of temperate cultivars even after correction suggests that there is a genetic variation of adaptation to a tropical environment independent of growth duration. Additionally, there was considerable performance variation within temperate cultivars.     

Willingness-to-pay for prescribed fire in the Colorado (USA) wildland urban interface

During the summer of 2001, survey data were collected from Colorado residents living near public lands (i.e., the wildland urban interface). Data were collected by telephone after mailing respondents a survey. These data include detailed information of respondents' views towards wildfire management and willingness-to-pay (WTP) values for prescribed burning. Results indicate that Colorado residents living near public lands are aware that fire is a natural process in their area and are in favor of using prescribed burning for fire risk reduction. They also are willing-to-pay an annual tax for prescribed fire undertaken on the public lands near their homes. Respondents' support for adopting a fire risk mitigation policy based on prescribed fire depended on perceived fire frequency intervals. The substantial WTP values for prescribed burning indicate that the public living in the wildland urban interface could potentially pay an annual tax, so the burden of wildfire management need no longer predominantly lie in the hands of the general taxpayers.     

Genetic variability and heritability estimates for hardseededness and flowering in balansa clover (Trifolium michelianum Savi) populations

Suitability of annual pasture legume species like balansa clover (Trifolium michelianum Savi) in southern Australian farming systems depends on their hardseededness and time to flowering. Late maturing varieties with increased rate of hardseed breakdown, particularly in the late summer—early autumn period are desirable to ensure reliable regeneration in permanent pastures. Two half-sib family balansa clover populations were used to estimate heritability for the rate of breakdown of hardseededness and time to flowering. High narrow-sense heritability estimates (90.5–96.1%, rate of hardseed breakdown; 85.9–94.5%, time to flowering) were obtained, and were mainly attributed to additive gene effects. There was no relationship between rate of hardseed breakdown and time to flowering in Group1 half-sib family, which indicated that selection for both traits could be undertaken independently. In half-sib family Group 2 the relationship between the two traits suggested the possibility of selecting late maturing cultivars with increased rate of hardseed breakdown. Significant differences in time to flowering and rate of hardseed breakdown both within and between the two half-sib family groups suggested that phenotypic recurrent selection would be effective in improving the traits in these populations.     

Age-dependent patterns of bovine tuberculosis in cattle

Bovine tuberculosis (BTB) is an important livestock disease, seriously impacting cattle industries in both industrialised and pre-industrialised countries. Like TB in other mammals, infection is life long and, if undiagnosed, may progress to disease years after exposure. The risk of disease in humans is highly age-dependent, however in cattle, age-dependent risks have yet to be quantified, largely due to insufficient data and limited diagnostics. Here, we estimate age-specific reactor rates in Great Britain by combining herd-level testing data with spatial movement data from the Cattle Tracing System (CTS). Using a catalytic model, we find strong age dependencies in infection risk and that the probability of detecting infection increases with age. Between 2004 and 2009, infection incidence in cattle fluctuated around 1%. Age-specific incidence increased monotonically until 24–36 months, with cattle aged between 12 and 36 months experiencing the highest rates of infection. Beef and dairy cattle under 24 months experienced similar infection risks, however major differences occurred in older ages. The average reproductive number in cattle was greater than 1 for the years 2004–2009. These methods reveal a consistent pattern of BTB rates with age, across different population structures and testing patterns. The results provide practical insights into BTB epidemiology and control, suggesting that targeting a mass control programme at cattle between 12 and 36 months could be beneficial.