Gas emissions from dairy cows fed typical diets of Midwest, South, and West regions of the United States

Gas emissions were determined for dairy cows fed three diets formulated to represent feed ingredients typical of the Midwest, South, or West regions of the United States. Dairy cows were housed and monitored in 12 environmentally controlled rooms (4 cows diet). Two experiments were performed, representing two lactation stages (initial days in milk were 115 ± 39 d in Stage 1 and 216 ± 48 d in Stage 2). The results demonstrated that the combination of different dietary ingredients resulted in different gas emissions while maintaining similar dry matter intake (DMI) and milk yield (MY). Diet effect on ammonia (NH) emissions was more prominent in Stage 1. During Stage 1, cows fed the Midwest diet had the highest daily NH emission, corresponding to the highest crude protein (CP) concentration among the three regions. The differences in NH emissions (39.0%) were much larger than the percent difference in CP concentrations between diets (6.8%). Differences in N intake, N excretion, or milk urea N alone may not serve as a strong indicator of the potential to reduce NH emissions. Lower emissions of methane (CH) per unit DMI or per unit MY were observed for cows offered the South diet during Stage 1 as compared with that from cows offered the Midwest or West diets. No diet effect was observed for hydrogen sulfide (HS) emission per unit S intake, nor for nitrous oxide (NO) emission. The measured NH and CH emissions were comparable, but the NO emissions were much higher than those reported for tie-stall dairy barns in the literature.     

Prioritizing islands for the eradication of invasive vertebrates in the United Kingdom overseas territories

Invasive alien species are one of the primary threats to native biodiversity on islands worldwide. Consequently, eradicating invasive species from islands has become a mainstream conservation practice. Deciding which islands have the highest priority for eradication is of strategic importance to allocate limited resources to achieve maximum conservation benefit. Previous island prioritizations focused either on a narrow set of native species or on a small geographic area. We devised a prioritization approach that incorporates all threatened native terrestrial vertebrates and all invasive terrestrial vertebrates occurring on 11 U.K. overseas territories, which comprise over 2000 islands ranging from the sub‐Antarctic to the tropics. Our approach includes eradication feasibility and distinguishes between the potential and realistic conservation value of an eradication, which reflects the benefit that would accrue following eradication of either all invasive species or only those species for which eradication techniques currently exist. We identified the top 25 priority islands for invasive species eradication that together would benefit extant populations of 155 native species including 45 globally threatened species. The 5 most valuable islands included the 2 World Heritage islands Gough (South Atlantic) and Henderson (South Pacific) that feature unique seabird colonies, and Anegada, Little Cayman, and Guana Island in the Caribbean that feature a unique reptile fauna. This prioritization can be rapidly repeated if new information or techniques become available, and the approach could be replicated elsewhere in the world. Priorización de Islas para la Erradicación de Vertebrados Invasores en los Territorios Exteriores del Reino Unido     

Use of chironomid deformities to assess environmental degradation in the Yamaska River,Quebec

The frequency of morphological deformities in chironomid larvae was used to assess environmental degradation at 12 sites in the Yamaska River, Quebec, that were known to be either impacted by agriculture or urban centres, or were relatively clean and used as reference sites. A total of 2273 chironomid larvae were examined for deformities. The overall frequency of deformities at polluted sites was 2.7%, whereas no deformities were observed at the reference sites. The highest incidence of deformities was found downstream of two urban centres, site 9 at Acton Vale (5.1% deformed) and site 12 at Ste Hyacinthe (5.3% deformed). The frequency of deformities at the agricultural sites ranged from 0.8 to 2.5% and was comparable to sites receiving municipal sewage effluent. The occurrence of higher frequencies of deformities downstream of urban centres indicates that the frequency of deformities increases with environmental degradation.     

Influence of a diet of fluoride-fed cockerels on reproductive performance of captive American kestrels

In 1982, twenty-four pairs of captive American kestrels (Falco sparverius) were forced to renest by removal of their first clutches 6 days after their completion. Immediately following, each of three groups of eight pairs was randomly assigned to one of three daily dietary regimes for 10 days: (1) three 1-day old cockerels with background levels of F(-) (62.4+/-51ppm, mean+/-SD) in their femurae, (2) two 10-day old cockerels with 4512+/-810ppm of F(-) in their femurae, (3) two 10-day old cockerels with 7690+/-417ppm of F(-) in their femurae. Fluoride levels in femurae of treated kestrels were significantly (P<0.0025) higher than those of control birds. Clutch sizes tended to be smaller as more fluoride was added to the diet, but not significantly so, due to an increase of the variance in the treatment group. Per cent fertility and per cent hatchability were not significantly affected by treatment. The fluoride content in eggshells in the fluoride-treated groups differed significantly from those of the control group (P<0.001).     

Use of in vivo phycocyanin fluorescence to monitor potential microcystin-producing cyanobacterial biovolume in a drinking water source

The source water of a drinking water treatment plant prone to blooms, dominated by potential microcystin-producing cyanobacteria, was monitored for two seasons in 2007-2008. In the 2008 season, the median value for potential microcystin-producing cyanobacterial biovolume was 87% of the total phytoplankton biovolume in the untreated water of the plant. Depth profiles taken above the plant's intake identified three sampling days at high risk for the contamination of the plant's raw water with potentially toxic cyanobacteria. Chlorophyceae and Bacillariophyceae caused false positive values to be generated by the phycocyanin probe when cyanobacteria represented a small fraction of the total phytoplanktonic biovolume present. However, there was little interference with the phycocyanin probe readings by other algal species when potential microcystin-producing cyanobacteria dominated the phytoplankton of the plant's untreated water. A two-tiered method for source water monitoring, using in vivo phycocyanin fluorescence, is proposed based on (1) a significant relationship between in vivo phycocyanin fluorescence and cyanobacterial biovolume and (2) the calculated maximum potential microcystin concentration produced by dominant Microcystis sp. biovolume. This method monitors locally-generated threshold values for cyanobacterial biovolume and microcystin concentrations using in vivo phycocyanin fluorescence.     

Diversity and team outcomes: the moderating effects of outcome interdependence and group longevity and the mediating effect of reflexivity

Reflexivity—the extent to which teams reflect upon and modify their functioning—has been identified as a possible key factor in the effectiveness of work teams. We examined the extent to which team composition affected team process (i.e., reflexivity) and in turn team outcomes (i.e., satisfaction, commitment, and performance). The results of diversity research thus far have been inconclusive in terms of positive or negative effects of team composition on team process and outcomes. In the current research, group longevity and outcome interdependence were expected to moderate the relationship between diversity on the one hand and reflexivity and team outcomes on the other hand. Reflexivity was expected to mediate these interaction effects. The current field study was conducted among 54 work teams from 13 different organizations. As predicted, few main effects were found. Instead, analyses showed interaction effects of diversity and outcome interdependence on the measures of reflexivity, satisfaction, and performance. As predicted, interaction effects were also found for diversity and group longevity on the measures of reflexivity, satisfaction, and performance. Three‐way interactions were found for satisfaction and commitment. Also, reflexivity was shown to mediate these relationships, indicating that the moderating effects of outcome interdependence and group longevity on the relation between diversity and team outcomes are due to the effects on process. Copyright © 2003 John Wiley & Sons, Ltd.     

GIS As A Tool For Assessing The Influence Of Countryside Designations and Planning Policies On Landscape Change

The county of Bedfordshire is typical of landscape in lowland England with land cover dominant over land form and agriculture forming the major land use. Landscape change can be influenced by planning policies through their control of land use. A number of designated areas such as Areas of Great Landscape Value, Areas of Outstanding Natural Beauty and Green Belt have been defined where particular planning priorities for the conservation of the countryside apply. This paper reports work where an attempt has been made to measure the influence of these designations on landscape change using the tools of aerial photograph interpretation and Geographic Information Systems (GIS). Aerial photographs were available for the study area for 1968, 1981 and 1991. These were interpreted to a landscape classification scheme in terms of point, linear and area features such as trees, hedgerows and cultivated land, respectively. Field work was carried out to assess the accuracy of the interpretation. The resulting data were input to a GIS for each date of photography. Digital maps were created for the land cover features and tables were generated of lengths of linear features or counts of point features for each kilometre square in the study area. Spatial analysis tools provided by the GIS were used to describe the landscape character of each of the designated areas and then to measure the change that had taken place within them over the time period defined by the photography. Areas which were not designated for conservation of scenic beauty were shown to be poorer in traditional landscape features.     

Rabbit biocontrol and landscape‐scale recovery of threatened desert mammals

Funding for species conservation is insufficient to meet the current challenges facing global biodiversity, yet many programs use expensive single‐species recovery actions and neglect broader management that addresses threatening processes. Arid Australia has the world's worst modern mammalian extinction record, largely attributable to competition from introduced herbivores, particularly European rabbits (Oryctolagus cuniculus) and predation by feral cats (Felis catus) and foxes (Vulpes vulpes). The biological control agent rabbit hemorrhagic disease virus (RHDV) was introduced to Australia in 1995 and resulted in dramatic, widespread rabbit suppression. We compared the area of occupancy and extent of occurrence of 4 extant species of small mammals before and after RHDV outbreak, relative to rainfall, sampling effort, and rabbit and predator populations. Despite low rainfall during the first 14 years after RHDV, 2 native rodents listed by the International Union for Conservation of Nature (IUCN), the dusky hopping‐mouse (Notomys fuscus) and plains mouse (Pseudomys australis), increased their extent of occurrence by 241–365%. A threatened marsupial micropredator, the crest‐tailed mulgara (Dasycercus cristicauda), underwent a 70‐fold increase in extent of occurrence and a 20‐fold increase in area of occupancy. Both bottom‐up and top‐down trophic effects were attributed to RHDV, namely decreased competition for food resources and declines in rabbit‐dependent predators. Based on these sustained increases, these 3 previously threatened species now qualify for threat‐category downgrading on the IUCN Red List. These recoveries are on a scale rarely documented in mammals and give impetus to programs aimed at targeted use of RHDV in Australia, rather than simply employing top‐down threat‐based management of arid ecosystems. Conservation programs that take big‐picture approaches to addressing threatening processes over large spatial scales should be prioritized to maximize return from scarce conservation funding. Further, these should be coupled with long‐term ecological monitoring, a critical tool in detecting and understanding complex ecosystem change.