Land-cover and structural changes in a western Norwegian cultural landscape since 1865, based on an old cadastral map and a field survey

Many studies of land-cover and structural changes in cultural landscapes have used historical maps as a source for information about past land-cover. All transformations of historical maps onto modern coordinate systems are however burdened with difficulties when it comes to accuracy. We show that a detailed land survey of the present landscape may enable transformation of an old cadastral map directly onto the present terrain with very high accuracy. The detailed resulting map enabled us to locate remnants of semi-natural grasslands and man-made structures with continuity from 1865 and to test hypotheses about relationships between landscape changes and landscape characteristics. The main land-cover change 1865–2002 was decrease of arable fields, and addition of three new land-cover classes: horticultural, orchard and abandoned areas. Of the 330 man-made structures present in 1865, only 58 remained in 2002, while 63 new structures had been built after 1865. We found that semi-natural grasslands with continuity since 1865 were situated on ground with significantly lower production capacity than mean 1865 production capacity. The man-made structures with continuity since 1865 were also associated with areas with significantly lower production capacity than the 1865 mean, situated in significantly steeper terrain but not further from the hamlet. Our study illustrates the potential of digitised and accurately transformed historical cadastral maps combined with detailed field surveys for analysis of land-cover and structural changes in the cultural landscape.     

Equal performance of TaqMan, MGB, molecular beacon, and SYBR green-based detection assays in detection and quantification of roundup ready soybean

We have tested and compared the performance of 12 different assays representing four different real-time polymerase chain reaction (PCR) chemistries in the context of genetically modified organism detection. Several different molecular beacon, SYBR Green, TaqMan, and MGB assays were designed for the event specific detection and quantification of the 3' integration junction of GTS 40-3-2 (Roundup Ready) soybean. Sensitivity as well as robustness in the presence of background DNA were tested. None of the PCR-based approaches appeared to be significantly better than any of the other, but the molecular beacon assays had the lowest efficiency and also seemed more sensitive to changes in experimental setup.     

Interaction between Plant Nutrients: II. Effect of Chloride on Activities of Cations in Soil Solution and on Nutrient Uptake by Plants

Abstract

In soil solutions the sum of cations is equivalent to that of anions. Anions are soluble or precipitated as less soluble salts. Therefore, the sum of soluble anions are responsible for the sum of cations in the soil solution. Soluble nitrate anions are unstable as they immobilize in biological materials. Hydrogen carbonate is excreted from plant roots and decomposes into carbon dioxide and carbonate. Carbonate reacts with hydrogen ions and forms complexes and ion pairs with calcium ions. Sulphate and chloride are more stable in the soil solution as anions.

Chloride ions were found to increase the activity of cations in the soil solution and to increase uptake of cations through the entire growth period. Increased absorption of cations increased yield. In temperate climate regions the surplus of chloride leaches from the root zone during winter.     

Efficiency of a dual density studded fish pass designed to mitigate for impeded upstream passage of juvenile European eels (Anguilla anguilla) at a model Crump weir

This study demonstrated that juvenile (glass) eels used a specific substrate (eel tiles) to circumvent a model Crump weir under an experimental setting. Upstream passage efficiency was 0 and 67% for the unmodified (no studded eel tiles on the downstream face; control) and modified (with studded eel tiles on the downstream face; treatment) set‐ups, respectively, and was greater for a small (59%) compared to large (41%) stud configuration. Eels were active and motivated to ascend the weir during both control and treatment set‐ups. Approach and attempt rates were elevated during the first few minutes of the treatment compared to control trials. Eels were edge‐oriented under both set‐ups and ascended the weir through the tiles during single burst swimming events (reaching estimated speeds of 68.5 cm·s⁻¹). Eel tiles may provide a cost‐effective solution for mitigating impacts of anthropogenic barriers to juvenile eel migration. Further research is required to determine passage efficiencies under higher flows, for a greater size range of eel, and for other migratory anguilliform fish (e.g. lamprey, Lampretra spp. and Petromyzon marinus L.). The performance of eel tiles should be validated through robust field studies.     

The geographic impact of ‘open skies’ policies on Trans‐Tasman air passenger service

Abstract: The goal of this paper is to examine the various geographic shifts occurring in New Zealand air passenger service as a result of the liberal aviation policies pursued by the country. A brief history of New Zealand air passenger travel both domestically and internationally will be followed by a more in‐depth investigation into the impacts of the single aviation market between New Zealand and Australia, first negotiated in 1992, subsequently altered in 1996 and, in its present form, agreed to in 2000. Particular attention is given to the increased competition that has arisen in the Trans‐Tasman market, making it one of the most heavily contested routes in global aviation. The Trans‐Tasman is analysed at a variety of levels, including airline competition, market growth, and fare changes that have occurred in the five years since the ‘full open skies’ agreement came into effect.     

Certification of forestry: A small-scale forester perspective

A perspective is presented on the role of forest certification in general and concerning small-scale forestry in particular. Certification may be viewed as a tool to communicate with consumers, as a tool to influence forest management or as a game of power and money. Market studies indicate that the end consumers have little interest in certification; the process seems to be more of an issue for some large retailers of wood products. The impact of certification on forest management and thus on the environment has not been studied extensively, and the original objective to stop devastation of tropical forests has so far failed. Certification is a new type of regulation, not based on democratic institutions. Equal treatment, correct procedures for appeal and transparency of decision processes are issues of governance yet to be addressed. The market penetration of certification is increasing, but its importance is an open question. One possible scenario is that large retailers and their large suppliers will adopt certification while the large number of smaller forest owners, wood processors and dealers abstain. Small-scale forest owners do well to develop their own standpoint vis-à-vis certification and marketing.     

A cryptic sulfur cycle in oxygen-minimum-zone waters off the Chilean coast

Nitrogen cycling is normally thought to dominate the biogeochemistry and microbial ecology of oxygen-minimum zones in marine environments. Through a combination of molecular techniques and process rate measurements, we showed that both sulfate reduction and sulfide oxidation contribute to energy flux and elemental cycling in oxygen-free waters off the coast of northern Chile. These processes may have been overlooked because in nature, the sulfide produced by sulfate reduction immediately oxidizes back to sulfate. This cryptic sulfur cycle is linked to anammox and other nitrogen cycling processes, suggesting that it may influence biogeochemical cycling in the global ocean.     

Bird predation effects on bush canopy arthropods in suburban forests

Urban and suburban forests provide important recreational values to the public and can also contain high levels of biodiversity even though management regimes of such forests often include the clearing of bushes, shrubs and small trees to make them more attractive to people. In a field experiment, we studied the importance of bush canopies as foraging sites for insectivorous birds. In suburban forests, the canopies of rowan (Sorbus aucuparia) and alder buckthorn (Frangula alnus) were net-enclosed for two months at three study sites in SW Sweden. We compared abundance, biomass and body size distributions of arthropods between experimental and control canopies of rowan and alder buckthorn and found the effects to be strong. Biomass of arthropods was generally an order of magnitude higher on canopies protected from bird predation than on controls. Dermaptera contributed most to the biomass estimated in net-enclosed bushes. In certain taxa, however, the biomass was not significantly affected by the experimental treatment, possibly in part due to on-going reproduction during the experimental period. Furthermore, median body size in net-enclosed bushes was 1.3–3.0 times the control, excluding Araneae. The relative difference in arthropod biomass due to the experimental treatment was related to the density of breeding insectivorous birds at each site. We concluded that bush canopies are important foraging sites for birds in suburban forests, although we cannot rule out trait-mediated effects. Management regimes that include clearing of the ground may affect the bird community negatively.