Ecosystem service values and land use change in the opium poppy cultivation region in Northern Part of Lao PDR

Land use change and land-cover impacts ecosystem services and functions. In this paper according to the study area’s land use characteristic and ecosystem type, the Land use category of the study area was divided into seven categories, including Forest, Grassland, Farmland, Water, Wetlands, Urban land and Barren land. The dynamic information of the forest Land use change during 10 years was calculated by the map algebra in ArcGIS 9.2. Both in 1992 and in 2002, Forest and Grassland were two largest Land use category in the study area. Forest took up 44.7% and 39.4% of the total area, and Grassland was 50.13% and 50.72% of the total area in 1992 and 2002. Finally, we valued change in ecosystem services delivered by each land use category using coefficients published by Costanza et al. [5]. Ecosystem services value of study area, the total ecosystem services value of 10.6 million hectares of this study area decreased by 11.74%. From the coefficient of sensitivity (CS) was less than unity in all case, it indicated that the total ecosystem services values was relatively inelastic and the results suggest that we have to pay attention more on land use change and finally, policy for driving forces of land use change were developed.     

毛乌素沙地南缘沙漠化临界区域土壤养分的空间异质性

毛乌素沙地南缘沙漠化临界区域是沙地-草地景观界面的关键部位,研究该区域土壤养分的空间格局和生态学过程,对于土地沙漠化的机理研究具有重要的意义。采用经典统计与地统计学相结合的方法,通过半变异函数及其模型、克里格局部插值估计、空间分布图等研究了毛乌素沙地南缘沙漠化临界区域土壤养分的空间异质性特征。结果表明:研究区土壤速效钾含量符合球状模型,全氮和速效磷含量符合指数模型;速效钾含量具有强空间自相关性,其结构方差比为0.882,而全氮和速效磷含量表现为中等程度的空间自相关性,其结构方差比分别为0.501和0.514;3种土壤养分空间自相关距离存在差异,其中全氮和速效钾的变程均为511m,而速效磷的变程为143m;3种土壤养分的分布格局呈现明显的空间规律性,从牛枝子群落到黑沙蒿群落,速效钾和速效磷含量先降低后升高,与研究区的界面变化过程一致,而全氮含量逐渐降低,与研究区的植被覆盖度变化一致;3种土壤养分的标准差都较小,Kriging插值结果比较可靠。     

Structural and immunocytochemical characterization of the Ginkgo biloba L. sperm motility apparatus

Summary. Ginkgo biloba and the cycads are the only extant seed plants with motile sperm cells. However, there has been no immunocytochemical characterization of these gametes to determine if they share characteristics with the flagellated sperm found in bryophytes and pteridophytes or might give clues as to the relationships to nonflagellated sperm in all other seed plants. To determine characteristics of proteins associated with the motility apparatus in these motile sperm, we probed thin sections of developing spermatogenous cells of Ginkgo biloba with antibodies to acetylated and tyrosinated tubulin and monoclonal antibodies that recognize mammalian centrosomes and centrin. The blepharoplast that occurs as a precursor to the motility apparatus consists of an amorphous core, pitted with cavities containing microtubules and a surface studded with probasal bodies. The probasal bodies and microtubules within the blepharoplast cavities are labeled with antibodies specific to acetylated tubulin. Positive but weak reactions of the blepharoplast core occur with the centrosomereactive antibodies MPM-2 and C-9. Reactions to centrin antibodies are negative at this developmental stage. From this pre-motility apparatus structure, an assemblage of about 1000 flagella and associated structures arises as the precursor to the motility apparatus for the sperm. The flagellar apparatus consists of a three-layered multilayered structure that subtends a layer of spline microtubules, a zone of amorphous material similar to that in the blepharoplast, and the flagellar band. Centrin antibodies react strongly with the multilayered structure, the transition zone of the flagella, and fibrillar material near the flagellar base at the surface of the amorphous material. Both the spline microtubules and all of the tubules in the flagella react strongly with the antibodies to acetylated tubulin. These localizations are consistent with the localizations of these components in pteridophyte and bryophyte spermatogenous cells, although the blepharoplast material surrounding and connecting flagellar bases does not occur in the seedless (nonseed) land plants. These data indicate that despite the large size of ginkgo gametes and the taxonomic separation between pteridophytes and Ginkgo biloba, similar proteins in gametes of both groups perform similar functions and are therefore homologous among these plants. Moreover, the presence of acetylated tubulin in bands of microtubules may be a characteristic shared with more derived non-flagellated sperm of other conifers and angiosperms. Correspondence and reprints: Southern Weed Science Research Unit, USDA Agricultural Research Service, P.O. Box 350, Stoneville, MS 38776, U.S.A.     

科尔沁沙地盐蒿种群的空间分布格局及关联性

以科尔沁沙地半固定沙丘和流动沙丘两种不同沙丘上的盐蒿(Artemisia halodendron)种群为研究对象,采用空间点格局方法研究了 0～20 m尺度上盐蒿种群的空间分布格局及其关联性.结果表明,半固定沙丘上盐蒿种群的数量远大于流动沙丘,不同生长发育阶段的种群结构呈偏正态分布,属于稳定型种群;流动沙丘上不同生长发...     

Colour polymorphism and thermal capacities in Theba pisana (O.F. Müller 1774)

Several land snail species are highly polymorphic regarding their shell colouration. This polymorphism has been related to predatory effects as well as climatic reasons, assuming that dark morphs benefit from being more cryptic and therefore less prone to predation, whereas pale morphs are at an advantage under solar radiation, as they are suspected to heat up less. However, the assumption of different thermal capacities of these morphs is based on experiments with little standardisation or little environmental relevance. In this study, we aimed at measuring thermal capacities of two different morphs (pale versus dark-brown banded) of the Mediterranean land snail Theba pisana, applying a standardised and environmentally relevant test set-up, in order to prove whether darker morphs indeed do heat up more than lighter coloured morphs. We did not find any differences in the thermal capacity of the different morphs and conclude that thermal capacity of the shell is predominantly defined by its material rather than its coloration. These results are discussed with regard to previous studies on thermal characteristics of different land snail morphs and correlations between climate and morph distribution.     

Evaluating the ability of regional models to predict local avian abundance

Spatial modeling over broad scales can potentially direct conservation efforts to areas with high species-specific abundances. We examined the performance of regional models for predicting bird abundance at spatial scales typically addressed in conservation planning. Specifically, we used point count data on wood thrush (Hylocichla mustelina) and blue-winged warbler (Vermivora cyanoptera) from 2 time periods (1995–1998 and 2006–2007) to evaluate the ability of regional models derived via Bayesian hierarchical techniques to predict bird abundance. We developed models for each species within Bird Conservation Region (BCR) 23 in the upper midwestern United States at 800-ha, 8,000-ha, and approximately 80,000-ha scales. We obtained count data from the Breeding Bird Survey and land cover data from the National Land Cover Dataset (1992). We evaluated predictions from the best models, as defined by an information-theoretic criterion, using point count data collected within an ecological subregion of BCR 23 at 131 count stations in the 1990s and again in 2006–2007. Competing (Deviance Information Criteria <5) blue-winged warbler models accounted for 67% of the variability and suggested positive associations with forest edge and proportion of forest at the 8,000-ha scale, and negative associations with forest patch area (800 ha) and wetness (800 ha and 80,000 ha). The regional model performed best for blue-winged warbler predicted abundances from point counts conducted in Iowa during 1995–1996 (r_s = 0.57; P = 0.14), the survey period that most closely aligned with the time period of data used for regional model construction. Wood thrush models exhibited positive correlations with point count data for all survey areas and years combined (r_s = 0.58, P ≤ 0.001). In comparison, blue-winged warbler models performed worse as time increased between the point count surveys and vintage of the model building data (r_s = 0.03, P = 0.92 for Iowa and r_s = 0.13, P = 0.51 for all areas, 2006–2007), likely related to the ephemeral nature of their preferred early successional habitat. Species abundance and sensitivity to changing habitat conditions seems to be an important factor in determining the predictive ability of regional models. Hierarchical models can be a useful tool for concentrating efforts at the scale of management units and should be one of many tools used by land managers, but we caution that the utility of such models may decrease over time for species preferring relatively ephemeral habitats if model inputs are not updated accordingly. © 2012 The Wildlife Society.     

Raw material selectivity in Late Pliocene Oldowan sites in the Makaamitalu Basin, Hadar, Ethiopia

We report the results of an analysis of raw material selection patterns in the assemblages from two Late Pliocene in situ archaeological localities in the Makaamitalu Basin (Hadar, Ethiopia). While the same local conglomerate was used as a raw material source for both archaeological occurrences, different selection criteria are identified. At A.L. 894, selection for quality is subtle and the clearest selection is against non-homogeneous raw materials. In the A.L. 666 assemblage, higher-quality raw materials were selected and some rare raw materials reached the locality from unknown sources. A comparison between the Makaamitalu and other Oldowan assemblages reveals an overall shift toward higher complexity of both selectivity and transport behaviors from ca. 2.0 Ma onward, contrasting a typo-technological conservatism that pertains until ∼1.6 Ma. It is hypothesized that an increase in complexity of behaviors related to raw material selection and acquisition involved changes in the intensity and fidelity of technological knowledge transmission.     

一次陆源降雨污水引起血红哈卡藻赤潮的成因

以2007年烟台四十里湾海域血红哈卡藻(Akashiwo sanguinea Hirasaka)赤潮为对象,研究赤潮消长与水环境因子的关系。研究发现大量陆源降雨污水输入后,海水盐度急剧下降、营养盐大幅增加,特别是活性磷酸盐浓度明显增加,促进了血红哈卡藻的生长繁殖并最终形成赤潮。赤潮发生前海区第一优势种为尖刺拟菱形藻(Pseudo-nitzschia pungens Halse),优势度0.47(0.42—0.52),多样性指数2.63(2.43—2.89);赤潮发生时血红哈卡藻密度范围1.05×105—4.10×106个/L,优势度0.92(0.83—0.99),多样性指数0.27(0.15—0.64);赤潮消退后中肋骨条藻(Skeletonema costatum Cleve)为第一优势种,优势度0.49(0.43—0.55),多样性指数2.46(2.19—2.84)。赤潮的发生、发展、消亡与化学需氧量(COD)、无机氮(DIN)、活性磷酸盐(DIP)、富营养化指数(E)呈显著正相关(P<0.05),与盐度呈显著负相关(P<0.01)。赤潮前、后该海域为贫营养、P限制、叶绿素a含量中等,赤潮期间该海域为富营养、P限制、叶绿素a含量高。通过影响力评定,活性磷酸盐、COD、盐度是此次赤潮发生的主要诱发因子,当活性磷酸盐含量低于0.3μmol/L时,硅藻逐渐取代甲藻,此次赤潮消散。     

Monitoring sandy desertification of Otindag Sandy Land based on multi-date remote sensing images

Sandy desertification is now the main ecological problem in the Otindag Sandy Land. In order to reveal the process of land degradation, especially the latest situation of sandy desertification, a method integrating remote sensing, Geographic Information System (GIS) and field survey was employed to build a sandy desertification dataset for analysis. Remote sensing images included the Landsat Thematic Mapper (TM) image in 1987, the Enhanced Thematic Mapper Plus (ETM⁺) image in 2000, and the image with the Charge-Coupled Device Camera (CCD) on the China-Brazil Earth Resources Satellite (CBERS) in 2006. Five land-cover classes, including active sand dunes, fixed sand dunes, semi-fixed sand dunes, inter-dune grassland and wetlands, were identified. Results showed that the Otindag Sandy Land has been suffering sandy desertification since 1987 with 2 different desertified stages. The first stage from 1987 to 2000 was a severe sandy desertification period, characterized by the fixed sand dunes decreasing at a high speed, and the semi-fixed and active sand dunes increasing remarkably. The second stage spanned from 2000 to 2006 and the sandy desertification was weakened greatly. Although a large area of fixed sand dunes were transformed to other types, fixed sand dunes were still the dominant type in the Ointdag region at 2006. Spatial change detection based on active sand dunes showed that the expansion area was much larger than the reversion area in the past two decades, and that several active sand belts had been formed, suggesting that sandy desertification controlling of the Otindag Sandy Land will be a long-term task.