Land management: data availability and process understanding for global change studies

In the light of daunting global sustainability challenges such as climate change, biodiversity loss and food security, improving our understanding of the complex dynamics of the Earth system is crucial. However, large knowledge gaps related to the effects of land management persist, in particular those human‐induced changes in terrestrial ecosystems that do not result in land‐cover conversions. Here, we review the current state of knowledge of ten common land management activities for their biogeochemical and biophysical impacts, the level of process understanding and data availability. Our review shows that ca. one‐tenth of the ice‐free land surface is under intense human management, half under medium and one‐fifth under extensive management. Based on our review, we cluster these ten management activities into three groups: (i) management activities for which data sets are available, and for which a good knowledge base exists (cropland harvest and irrigation); (ii) management activities for which sufficient knowledge on biogeochemical and biophysical effects exists but robust global data sets are lacking (forest harvest, tree species selection, grazing and mowing harvest, N fertilization); and (iii) land management practices with severe data gaps concomitant with an unsatisfactory level of process understanding (crop species selection, artificial wetland drainage, tillage and fire management and crop residue management, an element of crop harvest). Although we identify multiple impediments to progress, we conclude that the current status of process understanding and data availability is sufficient to advance with incorporating management in, for example, Earth system or dynamic vegetation models in order to provide a systematic assessment of their role in the Earth system. This review contributes to a strategic prioritization of research efforts across multiple disciplines, including land system research, ecological research and Earth system modelling.     

Using Poaching Levels and Elephant Distribution to Assess the Conservation Efficacy of Private,Communal and Government Land in Northern Kenya

Efforts to curb elephant poaching have focused on reducing demand, confiscating ivory and boosting security patrols in elephant range. Where land is under multiple uses and ownership, determining the local poaching dynamics is important for identifying successful conservation models. Using 2,403 verified elephant, Loxodonta africana, mortality records collected from 2002 to 2012 and the results of aerial total counts of elephants conducted in 2002, 2008 and 2012 for the Laikipia-Samburu ecosystem of northern Kenya, we sought to determine the influence of land ownership and use on diurnal elephant distribution and on poaching levels. We show that the annual proportions of illegally killed (i.e., poached) elephants increased over the 11 years of the study, peaking at 70% of all recorded deaths in 2012. The type of land use was more strongly related to levels of poaching than was the type of ownership. Private ranches, comprising only 13% of land area, hosted almost half of the elephant population and had significantly lower levels of poaching than other land use types except for the officially designated national reserves (covering only 1.6% of elephant range in the ecosystem). Communal grazing lands hosted significantly fewer elephants than expected, but community areas set aside for wildlife demonstrated significantly higher numbers of elephants and lower illegal killing levels relative to non-designated community lands. While private lands had lower illegal killing levels than community conservancies, the success of the latter relative to other community-held lands shows the importance of this model of land use for conservation. This work highlights the relationship between illegal killing and various land ownership and use models, which can help focus anti-poaching activities.     

Purification and Identification of the Fusicoccin Binding Protein from Oat Root Plasma Membrane

Fusicoccin (FC), a fungal phytotoxin, stimulates the H⁺-ATPase located in the plasma membrane (PM) of higher plants. The first event in the reaction chain leading to enhanced H⁺-efflux seems to be the binding of FC to a FC-binding protein (FCBP) in the PM. We solubilized 90% of the FCBP from oat (Avena sativa L. cv Victory) root PM in an active form with 1% octyl-glucoside. The FCBP was stabilized by the presence of protease inhibitors. The FCBP was purified by affinity chromatography using FC-linked adipic acid dihydrazide agarose (FC-AADA). Upon elution with 8 molar urea, two major protein bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with molecular weights of 29,700 and 31,000 were obtained. Successive chromatography on DEAE Bio-Gel A, hexyl agarose, and FC-AADA resulted in the same two bands when the FC-AADA was eluted with sodium dodecyl sulfate. A direct correlation was made between ³H-FC-binding activity and the presence of the two protein bands. The stoichiometry of the 29,700 and 31,000 molecular weight bands was 1:2. This suggests that the FCBP occurs in the native form as a heterotrimer with an apparent molecular weight of approximately 92,000.     

Bayesian estimation in animal breeding using the Dirichlet process prior for correlated random effects

In the case of the mixed linear model the random effects are usually assumed to be normally distributed in both the Bayesian and classical frameworks. In this paper, the Dirichlet process prior was used to provide nonparametric Bayesian estimates for correlated random effects. This goal was achieved by providing a Gibbs sampler algorithm that allows these correlated random effects to have a nonparametric prior distribution. A sampling based method is illustrated. This method which is employed by transforming the genetic covariance matrix to an identity matrix so that the random effects are uncorrelated, is an extension of the theory and the results of previous researchers. Also by using Gibbs sampling and data augmentation a simulation procedure was derived for estimating the precision parameter M associated with the Dirichlet process prior. All needed conditional posterior distributions are given. To illustrate the application, data from the Elsenburg Dormer sheep stud were analysed. A total of 3325 weaning weight records from the progeny of 101 sires were used.     

Posttraumatic stress symptoms after exposure to two fire disasters: comparative study

This study investigated traumatic stress symptoms in severely burned survivors of two fire disasters and two comparison groups of patients with "non-disaster" burn injuries, as well as risk factors associated with acute and chronic stress symptoms. Patients were admitted to one out of eight burn centers in the Netherlands or Belgium. The Impact of Event Scale (IES) was administered to 61 and 33 survivors respectively of two fire disasters and 54 and 57 patients with "non-disaster" burn etiologies at 2 weeks, 3, 6, 12 and 24 months after the event. We used latent growth modeling (LGM) analyses to investigate the stress trajectories and predictors in the two disaster and two comparison groups. The results showed that initial traumatic stress reactions in disaster survivors with severe burns are more intense and prolonged during several months relative to survivors of "non-disaster" burn injuries. Excluding the industrial fire group, all participants' symptoms on average decreased over the two year period. Burn severity, peritraumatic anxiety and dissociation predicted the long-term negative outcomes only in the industrial fire group. In conclusion, fire disaster survivors appear to experience higher levels of traumatic stress symptoms on the short term, but the long-term outcome appears dependent on factors different from the first response. Likely, the younger age, and several beneficial post-disaster factors such as psychosocial aftercare and social support, along with swift judicial procedures, contributed to the positive outcome in one disaster cohort.     

Influence of ammonium-N pulse concentrations and frequency,tank condition and nitrogen starvation on growth rate and biochemical composition ofGracilaria gracilis

The growth rate ofGracilaria gracilis maintained in tanks at an abalone farm near Port Elizabeth, South Africa, was examined under various tank conditions and NH₄-N pulse frequencies and concentrations. This was accompanied by analyses of the components of the internal nitrogen pool. A maximum growth rate of ca. 35% wk^–1 was obtained at 1200 M NH₄-N. The alga was able to grow at non-nitrogen limited rates using only internal stored nitrogen to sustain growth for one week before the growth rate decreased to ca. 17% per week. NH₄-N pulse frequency did not affect growth rate but one pulse per week led to a marked decrease in total-N, protein, phycoerythrin and chlorophyll-a content. An increase in pulse frequency to two pulses per week doubled the protein content from 2.351 ± 0.143 to 4.453 ± 0.090% (per unit dry mass). Carbohydrate content was inversely related to nitrogen storage. The growth rate in fouled tanks was always lower than in clean tanks. It seems likely that seaweeds and diatoms colonising the tank sides reduced light reflected off the inside of a tank, thereby reducing the growth rate.     

Glufosinate as an efficient inhibitor of callus proliferation in coffee tissue

Summary To improve selection of transgenic Coffea spp. tissue after transformation treatments, the effects of the selective agents chlorsulfuron, glufosinate, glyphosate, hygromycin, and kanamycin were studied on callus development from leaf explants (from greenhouse-grown plants and somaplants) and in embryogenic suspension cultures. Studied genotypes were from C. arabica, C. canephora, and the interspecific hybrids Arabusta and Congusta. A culture system based on “direct” somatic embryogenesis from C. canephora leaf explants proved to be more sensitive to selective agents than high frequency somatic embryogenesis from C. arabica or Arabusta leaf explants. With respect to the selective effect, chlorsulfuron and hygromycin provoked strong inhibition and severe necrosis, whereas glyphosate and kanamycin showed variable inhibition. Glufosinate appeared to efficiently inhibit growth of both leaf callus and callus suspensions of all genotypes tested without inducing necrosis. These properties may make the use of glufosinate advantageous in a selective growth system for detection of transformed coffee tissues.