‘Shifting ground’: Renegotiating land rights and rural livelihoods in Sarawak,Malaysia

In this paper, we use an actor‐oriented perspective to explore the nature and extent of conflict and negotiation with regard to land use and tenure among the Iban of Sarawak. The Iban are shifting cultivators who have long been involved in smallholder cash crops. We argue that the complexity of land‐use change and the major shifts in land law and policy in Sarawak in recent decades, particularly those favouring the rapid expansion of oil palm plantations on both state and customary land, have created a situation of indeterminacy that can be exploited to renegotiate land rights and livelihoods. We present a case history of an Iban community that has ‘shifted ground’ several times over the past century, both geographically and in its strategic position relative to state and private sector actors. We show how, under formidable pressure from these actors, this community has nevertheless renegotiated its access to land and other resources, and opportunistically developed a diversified livelihood system that has enabled it to survive in rapidly changing political and economic conditions. While not necessarily typical, the case sheds light on the limits and modes of negotiability in the context of a strong developmental state.     

The distribution of a threatened migratory bird species in a patchy landscape: a multi-scale analysis

Understanding the driving forces behind the distribution of threatened species is critical to set priorities for conservation measures and spatial planning. We examined the distribution of a globally threatened bird, the corncrake (Crex crex), in the lowland floodplains of the Rhine River, which provide an important breeding habitat for the species. We related corncrake distribution to landscape characteristics (area, shape, texture, diversity) at three spatial scales: distinct floodplain units (“floodplain scale”), circular zones around individual observations (“home range scale”), and individual patches (“patch scale”) using logistic regression. Potential intrinsic spatial patterns in the corncrake data were accounted for by including geographic coordinates and an autocovariate as predictors in the regression analysis. The autocovariate was the most important predictor of corncrake occurrence, probably reflecting the strong conspecific attraction that is characteristic of the species. Significant landscape predictors mainly pertained to area characteristics at the patch scale and the home range scale; the probability of corncrake occurrence increased with potential habitat area, patch area, and nature reserve area. The median potential habitat patch size associated with corncrake occurrence was 11.3 ha; 90% of the corncrake records were associated with patches at least 2.2 ha in size. These results indicate that the corncrake is an area-sensitive species, possibly governed by the males’ tendency to reside near other males while maintaining distinct territories. Our results imply that corncrake habitat conservation schemes should focus on the preservation of sufficient potential habitat area and that existing management measures, like delayed mowing, should be implemented in relatively large, preferably contiguous areas.     

F2 screening for resistance to pyramided Bacillus thuringiensis maize in Louisiana and Mississippi populations of Diatraea saccharalis (Lepidoptera: Crambidae)

BACKGROUND: In the mid‐southern region of the United States, sugarcane borer, Diatraea saccharalis (F.), is a major target pest of transgenic maize expressing Bacillus thuringiensis (Bt) proteins. Novel transgenic maize technologies containing two or more pyramided Bt genes for controlling lepidopteran pests have recently become commercially available. Insect resistance management (IRM) is an important issue in the sustainable use of Bt crop technologies. The objective of this study was to determine the frequency of resistance alleles in field populations of D. saccharalis to the new pyramided Bt maize technologies. RESULTS: A total of 382 F₂ family lines derived from 735 feral larvae/pupae of D. saccharalis collected from six locations in Louisiana and Mississippi during 2008 and 2009 were screened for resistance to three new Bt maize technologies: MON 89034, Genuity? VT Triple Pro? and SmartStax?. None of the 382 F₂ isoline families survived on the Bt maize leaf tissue for ≥ 12 days in the F₂ screen. The joint frequency for two‐ or three‐gene resistance models with 95% probability in these populations was estimated to be < 0.0063 to MON 89034 and < 0.003 to VT Triple Pro? and SmartStax?. CONCLUSION: These results suggest that the resistance allele frequency in D. saccharalis to the three pyramided Bt maize technologies is low in the mid‐southern region of the United States, which should meet the rare resistance assumption of the currently used IRM strategy for Bt maize. Copyright © 2011 Society of Chemical Industry     

Inconsistencies between Pangean reconstructions and basic climate controls

The supercontinent Pangea dominated our planet from the Permian into the Jurassic. Paleomagnetic reconstructions have been used to estimate the latitudinal position of Pangea during this 100-million-year period. Atmospheric circulation, recorded by eolian sandstones in the southwestern United States, shows a broad sweep of northeasterly winds over their northernmost extent, curving to become northwesterly in the south: This evidence is consistent with paleomagnetic reconstructions of the region straddling the equator in the Early Permian but is at odds with its northward movement to about 20 degrees N by the Early Jurassic. At least one of the following scenarios must be true: The latitude based on paleomagnetism is incorrect; the interpretation of how winds shaped the dunes is mistaken; the basic climate controls in the Jurassic were different from those of today; or the paleogeographic reconstructions available are insufficient to adequately reproduce the wind fields responsible for dune formation.     

Homeward sound

Despite spending weeks at sea as larvae, potentially scattered over many kilometers, young coral reef fish find suitable settlement habitat and in some cases return to their natal reefs. We report that some dominant families of larval reef fish use the sounds made by fish and shrimp resident on reefs to help them locate and settle on reefs and that some fish groups use specific components of the reef sound to guide their behavior. These findings could offer potential for active management of reef fisheries.     

Analysis of genetic diversity in farmers’ rice varieties in Sierra Leone using morphological and AFLP® markers

The objective of the current research was to investigate the status of rice genetic resources in post-war Sierra Leone using both morphological and amplified fragment length polymorphism (AFLP) data. Specifically, we aimed at investigating farmers’ rice genetic resources for homogeneity and differentiation, and at examining the genetic identity of similarly named varieties, including varieties within Sierra Leone, and between Sierra Leone and Guinea. This research was also motivated by the assumption that genetic erosion might have occurred as a result of the civil war. To determine the level of diversity and genetic relationships among farmers’ varieties of rice recently collected in Sierra Leone, two methods were used using subsets of the collected samples: (1) Using morphological data, 74 samples of 29 different varieties were analysed to investigate the relationship between (a) varieties grown in two districts in Sierra Leone, and (b) the two main cultivated species, Oryza sativa and Oryza glaberrima. A dendrogram largely clustered the varieties according to region and to the species to which the varieties belonged. (2) Using AFLP data, three separate investigations were conducted: (a) 33 samples of 10 varieties were investigated to evaluate diversity within and between varieties. The results indicated that the rice varieties possess different levels of intra-variety variation, whereas inter-variety diversity was high enough to distinguish one variety from the other. In particular, an AMOVA analysis revealed that 38 % of the total variation occurred within varieties, and 62 % between varieties. (b) 37 samples of 18 different varieties were investigated to determine the consistency of naming of varieties by farmers. The results showed that there was consistency in the naming by farmers of traditional varieties, but inconsistency in the naming of newly acquired varieties and cultivars. (c) 12 samples were investigated to check the identity of varieties carrying identical names collected in two separate regions, Sierra Leone and the neighbouring country of Guinea. The results indicated no close genetic relationships between the varieties found in Sierra Leone and Guinea despite similarities in the names given to these varieties by farmers, indicating the influence of different cultivation practices in the two countries.     

The effects of density on the behaviour and growth of juvenile blacklip abalone (Haliotis rubra)

The growth of juvenile abalone in aquaculture is known to be affected by density as a result of competition for food and decreases in water quality. Our results suggest that behaviour is also affected by density and this also has a significant impact on the growth of individual abalone. 1800 juveniles of Haliotis rubra were individually tagged and reared for 5 months in 12 gravity-fed tanks at two levels of density. The experimental design allowed the differentiation of the direct from the indirect effects of density. The abalone growth and distribution was monitored monthly along with the water quality. The distribution of abalone during daytime was closely related to the availability of preferred shelter space. The percentage of abalone stacked on the top of others increased with density. Preferred shelter space was characterized by low light intensity and a corner or edge for the abalone to rest against. Hides at the ends of the tanks were not occupied as much as others. Abalone were found crawling on the side of the tank during daytime when tanks were shaded. Abalone juveniles of 15–60 mm showed fidelity to their resting shelter during daytime but this fidelity was significantly reduced at the higher density. Shading of the tanks totally changed the distribution of the abalone and their daytime behaviour. Competition for shelter space reduced growth more than water quality. This revised version was published online in August 2006 with corrections to the Cover Date.