Krauchi N.,Kanton Aargau
Schweizerische Zeitschrift fur Forstwesen | Year: 2014
Driven by global trade and supported by climate change, we increasingly encounter new species in our ecosystems. Certain of these species, for example Asian Knotweeds (Reynoutria japonica, R. sachalinensis, R. × bohemica), exhibit immense growth rates and thereby suppress existing vegetation in revitalized reaches and biotopes deserving particular protection. The ecological damage accompanying the loss of biodiversity can only be contained by effective and efficient control measures. Contradictory legal guidelines at Federal level lead in practice to a conflict of aims, making goal-oriented control impossible. On the one hand the Chemical Risk Reduction Ordinance prohibits the use of pesticides in a 3-m strip along water stretches. On the other hand, numerous laws - such as the Federal Act on the Protection of Nature and Cultural Heritage, the Water Protection Law and the Ordinance on the Handling of Organisms in the Environment infer that it is a responsibility to protect riparian zones and river banks as ecologically valuable habitats, and to take measures against invasive neophytes. As long-term investigations in the Canton of Aargau have shown, chemical control sustainably weakens the Asian Knotweed. Further, a fluorescent tracer experiment demonstrated that with careful implementation, the use of pesticides along a 3-m strip along riverbanks poses no threat to the stretch of water. Therefore the Canton of Aargau hopes that these findings contribute to the fastest possible resolution of this conflict of aims, so that investments made over the past years towards restoring stretches of water may be protected promptly from the threat of Asian Knotweed.
Witschi A.-K.M.,ETH Zurich |
Liesegang A.,University of Zurich |
Gebert S.,Kanton Aargau |
Weber G.M.,DSM Nutritional Products Ltd |
Wenk C.,ETH Zurich
Journal of Animal Science | Year: 2011
Piglets are born with reduced plasmaconcentrations of 25-hydroxycholecalciferol (25-OH-D 3)and are thus highly predisposed to vitamin D deficiency.Furthermore, sow milk contains little vitamin D,and the slow intestinal vitamin D absorption of sowslimits the efficacy of dietary vitamin D supplementation.Hence, the neonate depends, to a large extent,on the vitamin D stores built up in fetal tissues frommaternal sources. The current study was undertakento evaluate whether the source and quantity of dietaryvitamin D provided to the gestating and lactating sow,and also directly in the form of creep feed to the piglet,would influence the vitamin D status, growth performance,and skeletal development of piglets. A total of39 primiparous and multiparous sows were randomlyassigned to 1 of 3 dietary treatments (13 in each treatment),supplemented with either 5 or 50 μg of the commonlyused cholecalciferol (vitamin D 3) or 50 μg of25-OH-D 3 per kilogram of feed. By wk 3 of lactation,piglets were offered a creep diet with vitamin D supplementationaccording to the treatment of the dam, andthey were offered the same creep diets after weaningat d 35 of age until they reached a BW of approximately20 kg. When dietary 25-OH-D 3 was provided,circulating concentrations of 25-OH-D 3 in piglet serumincreased (P < 0.05) as early as d 21 and later at d 33and 77, indicating greater body stores in those animals.Bone-breaking strength and cortical bone mineral contentand density at the tibial midshaft of piglets werereduced (P < 0.05) when vitamin D 3 was supplementedat 5 μg/kg compared with the bone traits of othergroups, but no differences (P > 0.05) were observedbetween the 2 other groups. After weaning, ADFI wasgreater (P < 0.05) and growth performance tended (P= 0.08) to improve when doses of 50 μg/kg were administered,regardless of the vitamin D source. In conclusion,supplementation of the diet with 50 μg/kg ofeither source of vitamin D was proved to be adequate inmeeting the needs of gestating sows and in permittingthe accumulation of vitamin D in fetal tissues, as wellas for normal skeletal mineralization and growth in theoffspring. Furthermore, the markedly improved vitaminD status of piglets whose mothers received 25-OH-D 3possibly resulted from greater tissue reserves presentat birth and a greater availability of vitamin D whenreleased from those stores. © 2011 American Society of Animal Science. All rights reserved.
Krauchi N.,Kanton Aargau |
Tschannen M.,Kanton Aargau
Schweizerische Zeitschrift fur Forstwesen | Year: 2015
Because of the reduced availability of soil resources, projects for flood control, renaturation or revitalisation of watercourses have been opposed on the grounds of their excessive consumption of land in general, and arable land in particular. By the way of the Water Protection Act, which has been revised and came into force in 2011, the Confederation obliges the cantons to prepare strategic plans for revitalisation of watercourses. In the Canton of Aargau, it is planned to revitalise 152 km of watercourses between 2015 and 2035, which will lead to the loss of 32 ha of arable land. This is about 1.5 ha per year, or 6% of the annual loss of arable land, which is about 24 ha per year. Three quarters of this total is lost to settlements. If one only considers losses outside built-up areas, in 2014, more than half was lost to buildings connected to agricultural activity. We can demonstrate, using the Siegfried maps of 1880, that more than 1,000 ha of former marsh and wetland are now arable land. The planned revitalisation of watercourses in Aargau over the next 20 years is equivalent to about 3% of the marsh and wetlands converted over the last 135 years. Revitalisation is compulsory, and the planned obligation to compensate the loss of arable land disregards the true situation: the major consumers of soil resources are settlements and, outside built-up areas, agriculture.