Habitat variables explain Loggerhead Shrike occurrence in the northern Chihuahuan Desert,but are poor correlates of fitness measures

Conservation efforts should be based on habitat models that identify areas of high quality and that are built at spatial scales that are ecologically relevant. In this study, we developed habitat models for the Loggerhead Shrike (Lanius ludovicianus) in the Chihuahuan Desert of New Mexico to answer two questions: (1) are highly used habitats of high quality for shrikes in terms of individual fitness? and (2) what are the spatial scales of habitat associations relevant to this species? Our study area was Fort Bliss Army Reserve (New Mexico). Bird abundance was obtained from 10 min point counts conducted at forty-two 108 ha plots during a 3-year period. Measures of fitness were obtained by tracking a total of 73 nests over the 3 years. Habitat variables were measured at spatial scales ranging from broad to intermediate to local. We related habitat use and measures of fitness to habitat variables using Bayesian model averaging. We found a significant relationship between bird abundance and measures of fitness averaged across nesting birds in each plot (correlation up to 0.61). This suggests that measures of habitat use are indicative of habitat quality in the vicinity of Fort Bliss. Local- and intermediate-scale variables best explained shrike occurrence. Habitat variables were not related to any measures of fitness. A better understanding of the factors that limit individual bird fitness is therefore necessary to identify areas of high conservation value for this species.     

Analysis on pedodiversity and spatial subset representativity—the German soil map 1:1,000,000

Knowledge about spatial soil variation in terms of measured pedodiversity, as well as the spatial distribution of soils in terms of spatial subset representativity, offers the possibility to estimate the quality and variance within a soil map. Additionally, it can help to identify representative sample locations. Demonstrated at the German soil map at a scale of 1:1,000,000, this study describes a methodology to analyze the distribution of taxonomical pedodiversity using the Simpson index and a new approach to derive representative spatial subsets based on a modified χ²‐test (χ_m²), which can be used as monitoring areas. To analyze the spatial composition of the soil map and to detect differences in the underlying mapping schemes of the German soil map 1:1,000,000, three different spatial data structures were studied: (1) the entire soil map, (2) the soil map segmented into geomorphological regions, and (3) the soil map segmented into the Federal States of Germany. Representative patches of varying sizes were statistically derived for all spatial subsets as well as the entire soil map ranging from 20 km × 20 km up to 70 km × 70 km. The results show that the measured pedodiversity is linked to both the geomorphology as well as the political borders of the Federal States. On the one hand, this reveals the uncertainty of measuring pedodiversity on the basis of soil‐class maps as the spatial representation of pedodiversity is influenced by the different mapping traditions and methods applied in the 16 Federal States of Germany. On the other hand, it allows the analysis of the aggregation schemes of different landscapes. The presented approach helps to understand large soilscapes and to compare different soil maps of different states and countries as well as to enhance the soil map with additional information. Furthermore, the representative patches can be used to select soil‐monitoring areas.     

Land-cover change and human population trends in the greater Serengeti ecosystem from 1984–2003

The growth of human populations around protected areas accelerates land conversion and isolation, negatively impacting biodiversity and ecosystem function, and can be exacerbated by immigration. It is often assumed that immigration around protected areas is driven by attraction in the form of economic benefits, but in many cases, people may be pushed from their areas of origin toward protected areas. Mitigating the effects of immigration around protected areas necessitates understanding the actual mechanisms causing it, which can be aided by analysis of patterns of land-cover change. Our goal was to identify the reasons for human population growth and land-cover change around the protected areas in the greater Serengeti ecosystem (henceforth “the park”), and to relate agricultural conversion from 1984–2003 to trends in human demography. We found that conversion of natural habitats to agriculture was greatest closer to the park (up to 2.3% per year), coinciding with the highest rates of human population growth (3.5% per year). Agricultural conversion and population growth were greatest where there was less existing agriculture, and population density was lowest. Lack of unfarmed land farther from the park, coupled with greater poverty near the park, suggest that movement away from areas with high population densities and land scarcity was likely driving immigration near the park, where arable land was available. Our results are essential for conservation planning for one of Africa’s hallmark ecosystems, and should encourage further examination of population growth and land-cover trends near protected areas throughout the developing world.     

Copying and manipulating nature: Innovation for textile materials

This paper considers the potential impact of biological approaches such as bio-copying (biomimetics) and biomanipulating (e.g. genetic engineering) on future developments in the field of textiles and, in particular, fibres. If analytical tools for studying biological systems combined with those of materials science are further developed, and higher efficiency and reproducibility of genetic engineering technology can be achieved, the potential for the copying and manipulation of nature for textile innovations will be immense. The present state for both fields is described with examples such as touch and close fastener, structurally coloured fibres, the Lotus effect (for bio-copying), as well as herbicide tolerant cotton, insecticide resistant cotton (Bt cotton), cotton polyester bicomponent fibres, genetically engineered silkworm and silk protein, and spider fibres (for genetic engineering). Dedicated to Prof. Dr.-Ing. Dr. h.c. mult. H. Zahn on the occasion of his 85^th birthday     

Induction, regulation and physiological role of IL-17 secreting helper T-cells isolated from PBMC, thymus, and lung lymphocytes of young pigs

Interleukin-17 (IL-17) producing cells, referred to as Th17, have recently emerged as a third subset of the T helper (Th) cell family. Studies in mice have demonstrated that Th17 cells and their associated cytokines are involved in several autoimmune diseases and host defense against infection. Murine Th17 cells differentiate from naïve CD4⁺ T-cells in the presence of TGFβ and IL-6, however, there are contradicting reports as to the role of TGFβ in the differentiation of human Th17 cells and very little is known about these cells in other animals. We report here the presence of IL-17 secreting lymphocytes in the lung and peripheral blood of pigs. The cDNA of porcine IL-17 gene was cloned and sequenced from activated lung lymphocytes and PBMC from piglets. A 17 kDa recombinant protein was expressed and purified both under denaturing and native conditions from E. coli BL21 cells. Furthermore, we demonstrate that TGFβ in the presence of IL-6 and/or IL-1β induces in vitro differentiation of Th17 cells from naïve porcine CD4⁺ thymocytes.     

Improved HPLC method for determination of phytosiderophores in root washings and tissue extracts

Phytosiderophores (PS) of the mugineic acid family can be separated effectively by HPLC on resin‐based anion exchange columns. Using gradient elution with aqueous NaOH, separation of 2'‐deoxymugineic acid (DMA), mugineic acid (MA), 3‐hydroxymugineic acid (HMA), 3‐epi‐hyydroxymugineic acid (epi‐HMA), and nicotianamine was obtained within 16 min with a complete cycle time of 30 min. Fluorimetric detection was performed after post‐column derivatization using sodium hypochlorite (NaOCl) and orthophtaldialdehyde. External standardization revealed a linear range between 0.1–2.5 nmol of each compound applied to the column, with a detection limit of approximately 0.05 nmol. Only minimal sample pre‐treatment by addition of sodium hydroxide (NaOH) was required prior to HPLC‐injection of natural occurring samples such as root exudates, collected from the whole root system or from single apical root zones, xylem sap, and hot water extracts of root material, obtained from iron (Fe)‐deficient maize and barley plants. The method is discussed in comparison with cation exchange HPLC which is conventionally employed for the separation of phytosiderophores.     

Iron transport in plants: Future research in view of a plant nutritionist and a molecular biologist

Iron is attractive to plant physiologists since J. Sachs has proven in 1868 the essentiality and the possible leaf uptake of Fe. It lasted about 100 years before the principal processes for Fe mobilization in the rhizosphere were discovered and classified as two distinct strategies for Fe acquisition. During the 80's and 90's of the last century the uptake of Fe²⁺ and Fe^III-phytosiderophores by specific transporters in strategy I- and strategy II-plants, respectively, were postulated without any application of the new approaching molecular techniques. In the following decade, the various transporters for Fe uptake by roots, such as AtIRT1 in Arabidopsis or ZmYS1 in maize and their possible regulation were characterized. In the following years with fast developing molecular approaches further Fe trans ortsrs were genetically described with often only vague physiological functions. In view of a plant nutritionist, besides uptake processes by roots, the following transport processes within the respective target tissue have to be considered by molecular biologists in more detail: 1) radial transfer of Fe from the root cortex through the endodermis, 2) xylem loading in roots, 3) transfer of Fe from xylem to phloem via transfer cells, 4) phloem loading with Fe in source leaves and retranslocation to sink organs, and 5) remobilization and retranslocation via the phloem during senescence of perennial plants. The importance of these various specific transport processes for a well-regulated Fe homeostasis in plants and new strategies to identify and characterize proteins involved in Fe transport and homeostasis will be discussed.     

Distribution pattern of root‐supplied 59iron in iron‐sufficient and iron‐deficient bean plants

In order to study the iron (Fe) distribution pattern in bean plants with different Fe nutritional status, french bean (Phaseolus vulgaris L.) seedlings were precultured in a complete nutrient solution with 8x10^‐5 M FeEDTA for five days. Thereafter, plants were further supplied with 8x10^‐5 M FeEDTA (Fe‐sufficient) or with only 2x10^‐6 M FeEDTA (Fe‐deficient) for another eight days. At this stage, the Fe‐deficient plants had much lower chlorophyll contents and lower dry weight of the leaves but higher reducing capacity of the roots compared with the Fe‐sufficient plants. For studies on short‐term distribution of Fe, the Fe‐sufficient plants were supplied 8x10^‐5 M ⁵⁹FeEDTA (specific activity 9.9 GBq/mol) and the Fe‐deficient plants 1x10⁶ M ⁵⁹FeEDTA (specific activity 98.8 GBq/mol). The plants were harvested after 4 and 24 hours. Despite a much lower supply of ⁵⁹FeEDTA/(factor 80), the Fe‐deficient plants took up significantly more ⁵⁹Fe but translocated less to the shoots (14.6% after 24 h) compared with the Fe‐sufficient plants (29.4% after 24 h). However, regardless of the Fe nutritional status of the plants, the majority of ⁵⁹Fe was translocated in the primary leaves. Our results demonstrate a similar distribution patterns of root‐derived ⁵⁹Fe in the shoots of Fe‐sufficient and Fe‐deficient plants, and thus, no preferential direct translocation of Fe to the shoot apex in the Fe‐deficient plants.     

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