Population densities and deforestation in the Brazilian Amazon: New insights on the current human settlement patterns

This paper provides the first analysis at the sub-municipality scale of the relationships between population densities and deforestation in the Brazilian Amazon between 2000 and 2010. We use the database on deforestation published by the Brazilian space research center (INPE) and the population census data released by the federal geographical and statistical agency IBGE at their finest scale: the census tract level. By crossing the population density and deforestation variables, we identify ten human settlement patterns in the Amazon. There are low-low and high-high classes of population density and deforestation, but also low-high and high-low classes. This analysis helps understand the low overall relations in the Amazon for population and deforestation. We emphasize the expansion of large-scale agriculture and cattle ranching as causing the depopulation of rural areas while in many regions of the Amazon quite strong population densities coexist with relatively low extents of deforestation. Such findings stress the need to implement case-specific public policies in these regions in order to encourage human presence compatible with the conservation of forest cover and biodiversity. We also confirm the importance of the Amazon urbanization process, including the ‘discrete urbanization’ of rural areas, and the need to better recognize the distinct social and environmental problems of urban areas.     

广东惠东县境内榄李种群的分布及保育策略

广东惠东县沿海真红树植物榄李生境存留面积13.85 hm2,分布于3个地点。其群落内共录得红树林植物7科9属9种,群落的整体物种多样性指数为0.956~1.565,均匀度指数为0.870~0.934,生境沉积物缺乏典型红树林沉积物的特性。惠东县的平海——黄埠榄李种群可确定为欧亚大陆分布最北缘的种群,针对该种群面临的环境威胁,提出了种群保育策略和措施。     

Do we prioritize floodplains for development and farming? Mapping global dependence and exposure to inundation

Global wetlands and floodplains offer benefits and perils alike for human society. For example, humans rely on natural flood cycles for fisheries and agriculture, yet flooding also caused nearly one trillion USD in damage in the past 30 years and impacts millions of people every year. Looking forward, altered flow regimes or increased drought conditions are expected to affect the natural inundation cycle and its ecosystem services. The current and potential future impacts of flooding and drying events warrant increasing efforts to quantify our dependence and exposure within flooded areas, since any change from current inundation patterns is expected to have consequences for those who rely on regular flood occurrences. This paper provides a baseline global assessment of the dependence and exposure of human populations, urban areas, roads, and agriculture on current inundation patterns. The analysis uses a spatially explicit inundation map at ∼500 m resolution (GIEMS-D15) derived from satellite remote sensing to represent flooding extents and overlays it with current population and land use maps. We find that 35% of the analyzed population, or 2.0 billion people, live inside areas that are prone to inland flooding, which comprise only 12% of the land surface area (excluding marine coastal areas), confirming that population densities within inundation zones are about three-times above global average. Likewise, 35% of urban areas potentially experience regular, seasonal, or infrequent flooding. Agriculture shows a similar pattern with 24% of the world’s cropland in areas of recurring inundation. Finally, we estimate that 18% of the global road network is exposed to inundation during high water periods. These global estimates demonstrate a preferential tendency of human populations, infrastructure, and agriculture to be co-located within inundation areas, making related anthropogenic activities highly susceptible to future changes in flood regimes. The results are intended to offer a suite of first-order estimates as partial input to more holistic risk and vulnerability assessments and to ultimately improve environmental planning and policy at large scales.     

Socio-economic and climatic changes lead to contrasting global urban vegetation trends

Urban greening can enhance quality of life by generating ecosystem services and has been proposed as a way of mitigating adverse consequences of global warming for human health. However, there is limited knowledge on global trends in urban vegetation and their relation to economic development and climate change. Here we studied 1,688 major cities worldwide and show that 70% (1,181) show an increase in vegetation derived from satellite observations (2000–2018). For 68% (1,138) of the cities studied, the increase in the urban vegetation is less strong as compared to the vegetation increase found in the surroundings of these cities. Overall, positive vegetation trends are widely observed in cities in Europe and North America, whereas negative vegetation trends in cities occur primarily in Africa, South America and Asia. Gross Domestic Product growth, population growth as well as temperature are found to be the main underlying drivers of the observed contrasts in changes in urban vegetation as compared to surrounding areas across continents. From a global synthesis of urban vegetation change, we quantify the role of social-economic development and climate change in regulating urban vegetation growth, and the contrasting imprint on cities of developed and developing countries.     

High resolution study of the abundance pattern of the heavy elements in very metal‐poor field stars

The abundances of heavy elements in EMP stars are not well explained by the simple view of an initial basic “rapid” process. In a careful and homogeneous analysis of the “First Stars” sample (eighty per cent of the stars have a metallicity [Fe/H] ≃ –3.1 ± 0.4), it has been shown that at this metallicity [Eu/Ba] is constant, and therefore the europium‐rich stars (generally called “r‐rich”) are also Ba‐rich. The very large variation of [Ba/Fe] (existence of “r‐poor” and “r‐rich” stars) induces that the early matter was not perfectly mixed. On the other hand, the distribution of the values of [Sr/Ba] vs. [Ba/Fe] appears with well defined upper and lower envelopes. No star was found with [Sr/Ba] < –0.5 and the scatter of [Sr/Ba] increases regularly when [Ba/Fe] decreases. To explain this behavior, we suggest that an early “additional” process forming mainly first peak elements would affect the initial composition of the matter. For a same quantity of accreted matter, this additional Sr production would barely affect the r‐rich matter (which already contains an important quantity of Sr) but would change significantly the composition of the r‐poor matter. The abundances found in the CEMP‐r+s stars reflect the transfer of heavy elements from a defunct AGB companion. But the abundances of the heavy elements in CEMP‐no stars present the same characteristics as the the abundances in the EMP stars. Direct stellar ages may be found from radioactive elements, the precision is limited by the precision in the measurements of abundances from faint lines in faint stars, and the uncertainty in the initial abundances of the radioactive elements. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

Validation of the three-dimensional ECOHAM model in the German Bight for 2004 including population dynamics of Pseudocalanus elongatus

A three-dimensional ecosystem model for the North Sea which includes competition between Pseudocalanus elongatus and the rest of the zooplankton biomass was applied to describe the seasonal cycle of zooplankton in 2003–2004. The paper presents the comparison of simulated stage-resolved abundances with copepod counts at several stations in the German Bight during the GLOBEC-Germany project from February to October 2004. A validation of influential state variables gives confidence that the model is able to calculate reliably the stage development and abundances of P. elongatus as well as the range of bulk zooplankton biomass, and thus the ratio of population biomass to total biomass. In the German Bight, the population is below 20% in spring. The ratio increases up to 50% during summer. The number of generations was estimated from peaks in egg abundance to about 4–8 generations of P. elongatus in the southern North Sea. A mean of four generations per year were estimated in the central North Sea, six to eight generations northwest of the Dogger Bank (tails end) and five generations in the German Bight.     

The Effects of Quality Control on Decreasing Error Propagation in the LandScan USA Population Distribution Model: A Case Study of Philadelphia County

LandScan USA is a 90 m population distribution model that is used for a variety of applications, including emergency management. Models should have a measure of accuracy; however, the accuracy of population distribution models is difficult to determine due to the inclusion of multiple input datasets and the lack of quantifiable, observable (validated) data to confirm model output. Validated data enables quantification of: (1) overall model accuracy and (2) changes in model output at different levels of quality control. This article examines the effect of quality control for two national school datasets incorporated as input in LandScan USA for Philadelphia County, Pennsylvania; which had a local, validated school dataset available. The effect of each stage of quality control efforts utilized throughout the LandScan USA process were assessed to determine what level of quality control was required to have a statistically significant change of the model's population distribution. The typical level of quality control for LandScan USA resulted in 36% of schools being moved to the correct location and 20% of missing student enrollments were found, compared to 87% and 98% respectively for the validated dataset. The costs of increasing quality control resulted in a six-fold increase in labor time; however, the additional quality control did not produce statistically significant improvements in the LandScan USA model. Thus, typical quality control efforts for schools in LandScan USA produced a population distribution similar to the validated level of quality control, and can be applied with confidence for policy, planning, and emergency situations.     

我国沿海鲻鱼(Mugil cephalus)不同地理群体形态差异研究

运用多变量形态度量学分析方法,对我国沿海的四个鲻鱼群体110个个体的形态变异进行了分析。聚类分析和主成分分析结果表明,位于我国南部沿海的广东湛江群体(ZJ)与福建厦门群体(XM)形态最为接近,位于北部沿海的河北塘沽群体(HB)与山东青岛群体(QD)的形态最为接近;而南、北部群体间的趋异程度较大,有一定程度的形态分化。主成分分析前3个主成分对不同群体间总变异方差的贡献率分别为:50.00%、12.16%、11.10%,累积贡献率为73.25%。主成分分析结果表明,四个鲻鱼群体在形态上的差别很大程度上是由体型的高低、长短引起的,且主要集中在胸部和尾部。判别分析中采用9个不同的变量,分别构建了四个鲻鱼群体的判别公式,判别正确率达到99.1%。     

水丰水库亚洲公鱼和大银鱼种群生态的比较研究

1998年 10月至 2 0 0 0年 11月对水丰水库亚洲公鱼和大银鱼的食性、生长、繁殖、群体结构进行了比较研究 .亚洲公鱼为杂食性鱼类但主要以浮游动物为食 ,繁殖时还摄食同类卵 ,出现频率达 4 2 .9% ,在冬季也摄食大银鱼卵 (2 .8% ) ;体长 (L)、体重 (W)呈异速生长 (W =1.176×10 - 6 L3.5555) ;群体繁殖速度比 1984年以前提高了 4 9.2 % ;群体结构中体长、体重的离散度很小 .大银鱼前期主要以浮游动物为食 ,后期以小鱼小虾为主要食物 ,也捕食公鱼 ,出现频率 6 .9% -9 6 % ;体长、体重呈等速生长 ,W =4 .4 82× 10 - 6 L3.0 0 0 9;群体繁殖速度高出公鱼 1.18倍 ;群体结构中体长、体重的离散度较大 ,表现出了个体间的差异性     

Expansion of round gobies in a non-navigable river system

A number of Ponto-Caspian Gobiid species have greatly increased their geographical ranges over recent decades. Most expansion studies to date, however, have focused on navigable waterways. In this study, we present a summary of six-years (2008–2013) monitoring of round goby Neogobius melanostomus expansion along two connected non-navigable rivers. Contiguous range expansion was observed in both rivers, with dispersal rate ranging from 1.2 to 3.2 km/year. Gobies at newly invaded sites ranged from 20 to 117 mm, with both juveniles and adult fish observed. Though the data did not allow us to see any consistent pattern in the first years after detection, there was some evidence for a shift to a female-biased, juvenile-dominated population over time. While the abundance of non-native tubenose goby Proterorhinus semilunaris appeared to be negatively influenced by round goby establishment, diversity of nearshore native fish showed no evidence of dramatic decline attributable to round goby.