Hydrologic impact of climate change with adaptation of vegetation community in a forest-dominant watershed

This study evaluated the impact on watershed hydrology by predicting future forest community change under a climate change scenario. The Soil and Water Assessment Tool (SWAT) was selected and applied to Chungju dam watershed (6,642 km²) of South Korea. The SWAT was calibrated and validated for 6 years (1998–2003) using the daily streamflow data from three locations. For the future evaluation of forest community and hydrology, the MIROC3.2 HiRes monthly climate data were adopted. The future data were corrected using 30 years (1977–2006, baseline period) of measured weather data, and they were daily downscaled by the Long Ashton Research Station-Weather Generator statistical method. To predict the future forest vegetation cover, the baseline forest community was modeled by a multinomial LOGIT model using variables of baseline precipitation, temperature, elevation, degree of base saturation, and soil organic matter, and the future forest community was predicted using the future precipitation and temperature scenario. The future temperature increase of 4.8 °C by 2080s (2070–2099) led to prediction of 30.8 % decrease of mixed forest and 75.8 % increase of coniferous forest compared to the baseline forest community. For the baseline evapotranspiration (ET) of 491.5 mm/year, the 2080s ET under the forest community change was 591.1 mm/year, whereas it was 551.8 mm/year with the remaining forest community stationary. The different ET results considering the future forest community clearly affected the groundwater recharge and streamflow in sequence.     

南平市近58年冬季气候变化及特征分析

利用南平市3个代表站1951-2009年气象资料,统计分析冬季降水和气温变化特征。结果显示,58年来南平市冬季平均气温呈上升趋势,平均最低气温上升明显,降水呈波动性,近10年呈相对少雨年。通过相关分析,用逐步回归方程建立冬季气温趋势预报。     

Modelling the impact of climate change on woody plant population dynamics in South African savanna

Background

In Southern Africa savannas climate change has been proposed to alter rainfall, the most important environmental driver for woody plants. Woody plants are a major component of savanna vegetation determining rangeland condition and biodiversity. In this study we use a spatially explicit, stochastic computer model to assess the impact of climate change on the population dynamics of Grewia flava, a common, fleshy-fruited shrub species in the southern Kalahari. Understanding the population dynamics of Grewia flava is a crucial task, because it is widely involved in the shrub/bush encroachment process, a major concern for rangeland management due to its adverse effect on livestock carrying capacity and biodiversity.

Results

For our study we consider four climate change scenarios that have been proposed for the southern Kalahari for the coming decades: (1) an increase in annual precipitation by 30–40%, (2) a decrease by 5–15%, (3) an increase in variation of extreme rainfall years by 10–20%, (4) and increase in temporal auto-correlation, i.e. increasing length and variation of periodic rainfall oscillations related to El Niño/La Niña phenomena. We evaluate the slope z of the time-shrub density relationship to quantify the population trend. For each climate change scenario we then compared the departure of z from typical stable population dynamics under current climatic conditions. Based on the simulation experiments we observed a positive population trend for scenario (1) and a negative trend for scenario (2). In terms of the projected rates of precipitation change for scenario (3) and (4) population dynamics were found to be relatively stable. However, for a larger increase in inter-annual variation or in temporal auto-correlation of rainfall population trends were negative, because favorable rainfall years had a limited positive impact due to the limited shrub carrying capacity.

Conclusions

We conclude that a possible increase in precipitation will strongly facilitate shrub encroachment threatening savanna rangeland conditions and regional biodiversity. Furthermore, the negative effects found for positive auto-correlated rainfall support current ecological theory stating that periodically fluctuating environments can reduce population viability because species suffer disproportionately from poor environmental conditions.     

The influence of climate change on irrigation water requirements for corn in the coastal region of Ecuador

This study investigated the irrigation water requirements (IWR) for corn in five provinces of the coastal region of Ecuador that have been influenced by climate change. The weather data were statistically downscaled from six General Circulation Models and compared with the current climate period from 1986 to 2012. CROPWAT 8.0 was used to estimate future IWR for corn cultivation from 2011 to 2100 based on the Representative Concentration Pathways 4.5 and 8.5 scenarios. Also the frequency of predicted rainfall for future periods was analysed to identify the possibility of obtaining the amount of water required for corn plantation from rainfall. The projected trend of future climate showed increases in temperature and rainfall. The predicted IWR showed a decreasing trend in the rainy season and a similar or slightly lower trend in the dry season. Sufficient rain for corn cultivation was predicted for the wet region of the study area, with lower IWR, whereas most of the dry region was shown to have similar patterns of current water demands, except an increase in predicted rainfall resulted in lower IWR in some parts of this region.     

茶园人工群落对微气候的影响

茶树原产于我国南亚热带森林群落中的一种伴生植物，由于人为的引种栽培，使之脱离了原有复杂的森林生态环境，变成为一种单纯的人工植物。这一改变不仅破坏了茶树的生态平衡，同时还白白浪费掉了立体空间中的许多宝贵资源。在我国多数茶区都分布在亚热带，茶树生长都是季节性的，从冬到春季长达5-6个月的时间里，专业茶场几乎无事可做。时间、人力白白消耗。同时纯茶园仅对距地表1米左右的空间进行了平面式的利用，较高层，地表层和地下层均未得到合理开发，科学利用。茶叶作为一种商品性饮料植物受市场变化的影响极大，市场滞销，单营就会…     

Long-term patterns in European brown hare population dynamics in Denmark: effects of agriculture, predation and climate

Background

In Denmark and many other European countries, harvest records suggest a marked decline in European brown hare numbers, a decline often attributed to the agricultural practice. In the present study, we analyse the association between agricultural land-use, predator abundance and winter severity on the number of European brown hares harvested in Denmark in the years 1955 through 2000.

Results

Winter cereals had a significant negative association with European brown hare numbers. In contrast to this, root crop area was positively related to their numbers. Remaining crop categories were not significantly associated with the European brown hare numbers, though grass out of rotation tended to be positively related. The areas of root crop production and of grass out of rotation have been reduced by approximately 80% and 50%, respectively, while the area of winter cereals has increased markedly (>70%). However, European brown hare numbers were primarily negatively associated with the number of red fox. Finally, we also found a positive association between mild winters and European brown hare numbers.

Conclusion

The decline of Danish European brown hare populations can mainly be attributed to predation by red fox, but the development in agricultural land-use during the last 45 years have also affected the European brown hare numbers negatively. Additionally, though mild winters were beneficial to European brown hares, the increasing frequency of mild winters during the study period was insufficient to reverse the negative population trend.     

Intercropping potatoes in early spring in a temperate climate. 3. The influence of planting date, row width and temperature change on the potential for intercropping

Summary The effects of planting date and row width on canopy development, intercepted radiation and yield were studied in two experiments, with the variety Wilja in 1988 and Cara in 1989. Planting dates were between mid March and early May and were combined with row widths of 0.75 and 1.25 m. Increasing the row width decreased intercepted radiation and yields in both years. Delayed planting reduced the yield of Cara, but not of Wilja. Early planting increased radiation use efficiency of Cara. It is argued that intercropping in spring without potentially reducing tuber yield might be favoured by delaying the planting of a determinate variety such as Wilja but by increasing the row width for an indeterminate variety such as Cara. Trends in mean monthly and soil 10 cm temperatures however suggest that opportunities for intercropping potatoes in the spring in a temperate climate may become more restricted.     

Tetrodotoxin sensitivity of the vertebrate cardiac Na+ current

Evolutionary origin and physiological significance of the tetrodotoxin (TTX) resistance of the vertebrate cardiac Na(+) current (I(Na)) is still unresolved. To this end, TTX sensitivity of the cardiac I(Na) was examined in cardiac myocytes of a cyclostome (lamprey), three teleost fishes (crucian carp, burbot and rainbow trout), a clawed frog, a snake (viper) and a bird (quail). In lamprey, teleost fishes, frog and bird the cardiac I(Na) was highly TTX-sensitive with EC(50)-values between 1.4 and 6.6 nmol·L(-1). In the snake heart, about 80% of the I(Na) was TTX-resistant with EC(50) value of 0.65 μmol·L(-1), the rest being TTX-sensitive (EC(50) = 0.5 nmol·L(-1)). Although TTX-resistance of the cardiac I(Na) appears to be limited to mammals and reptiles, the presence of TTX-resistant isoform of Na(+) channel in the lamprey heart suggest an early evolutionary origin of the TTX-resistance, perhaps in the common ancestor of all vertebrates.     

Salmon-derived nitrogen in terrestrial invertebrates from coniferous forests of the Pacific Northwest

Background  

Bi-directional flow of nutrients between marine and terrestrial ecosystems can provide essential resources that structure communities in transitional habitats. On the Pacific coast of North America, anadromous salmon (Oncorhynchus spp.) constitute a dominant nutrient subsidy to aquatic habitats and riparian vegetation, although the contribution to terrestrial habitats is not well established. We use a dual isotope approach of δ¹⁵N and δ¹³C to test for the contribution of salmon nutrients to multiple trophic levels of litter-based terrestrial invertebrates below and above waterfalls that act as a barrier to salmon migration on two watersheds in coastal British Columbia.     

Tension dynamics of the fibers in a triangular plane flow of bundle

The ring spinning method is broadly used for manufacturing various forms of yarns in various application fields in thanks of the outstanding yarn characteristics and the well established processing technology. However, applying the ring spinning for manufacturing functional yarn, for example, the core-spun yarn, often raises serious yarn quality problems. Especially, surface defects make it difficult to extend the technology to various end-purposes. Dynamic state of the tension of fibers in the spinning triangle that is considered as a triangular plane flow field plays an important role in causing the defects. In this study, a theoretical model describing the tension behavior of the fibers in the triangular plane flow field was derived and the availability of the model was tested experimentally. Results showed that the steady-state experiments brought good corresponding results with those from the theory, which identifies the effectiveness of the theoretical model. The tension dynamics of the fibers in spinning triangle could be expressed as a 1st order system, while the spinning triangle length and the process velocity could majorly affect the tension dynamic characteristics.     

Phenology and pest status of Agrotis segetum in a changing climate

Insects are strongly dependent on climatic factors, especially temperature. For this reason, changes in insect phenology are predicted to be one of the many effects of climate change. We analysed the effect of climate warming on Agrotis segetum (Denis & Schiffermüller) in Denmark. Agrotis segetum is an agricultural pest that causes root crop damage. Extensive registers of root crop damages by A. segetum in Denmark were kept between 1905 and 1980. These records show a correlation between A. segetum outbreaks and hot, dry summers. The last outbreak in Denmark, in 1976, prompted the implementation of pheromone trap monitoring. Data from these pheromone traps, for the periods between 1981–1991 and 1997–2009, show a decline in the number of A. segetum individuals during 2000–2009. We used this pheromone trapping data to test the hypothesis that temporal changes in phenology and abundance are correlated with temperature and precipitation patterns. As phenological fixed points, we use the time of capture (first, 10%, 50%, 90% and last) of 1st generation A. segetum together with the 10%–90% capture period and the total capture per location for a statistical comparison of the period 1981–1990 versus 2000–2009. We also analysed the effect of temperature on the timing of fixed points and the effect of precipitation on the mean total capture from the summer and the preceding winter. Our analyses showed an earlier occurrence of A. segetum during 2000–2009 than during 1981–1990: all phenological fixed points advanced by 6–9 days. Trap captures of the 1st generation roughly halved from the 1981–1990 decade to the 2000–2009 decade, and a much larger 2nd generation of moths developed in the latest decade. When a second generation occurs, populations in following years decrease because the larval offspring of the 2nd generation cannot successfully overwinter. Our analyses further indicated that increased precipitation during the summers and mild winters contributed to an overall decline in the populations of this pest. The presence of A. segetum remains sufficient to be a potential threat to yields. Forecasting an economically important attack of A. segetum is challenging because of the early emergence of A. segetum and more variable local weather conditions than 20 years ago; forecasting relies on the timely and correct delivery of monitoring results. Farmers are a vital source of information for monitoring, for estimating control requests and for timing the emergence of A. segtum. However, the growing frequency of no-risk forecasts has reduced the interest and lowered the motivation of farmers to participate in monitoring programs.     

Mygalomorph spider community of a natural reserve in a hilly system in central Argentina

Abstract The diversity, abundance, spatial distribution, and phenology of the mygalomorph spider community in the "Ernesto Tornquist" Strict Nature Reserve were analyzed in this study. Located in southwestern Buenos Aires, Argentina, the Reserve is representative of the Ventania system, which is a sigmoidal mountain belt 180 km in length. This exceptional hilly ecosystem is home for many endemic species and rich native fauna and flora. Spider abundance was sampled monthly from October 2009 to October 2010 by hand capture and pitfall traps on grassland slopes. The species recorded in the study area were: Actinopus sp.1 (Actinopodidae); Grammostola vachoni and Plesiopelma longisternale (Theraphosidae); Acanthogonatus centralis (Nemesiidae); and Mecicobothrium thorelli (Mecicobothriidae). Grammostola vachoni and Acanthogonatus centralis were the dominant species in hand capture and pitfall traps, respectively. The seasonal variation, diversity, and abundance of the mygalomorph community are analyzed and discussed here. The Mygalomorphae of the Ventania system comprises an important group of sedentary and cryptozoic spiders that seem to be highly dependent on habitat type and environmental factors.     

Numerical assessments of the impacts of climate change on regional groundwater systems in a paddy-dominated alluvial fan

Quantitative assessment of the impacts of climate change on groundwater levels is important for sustainable groundwater use. This study examined the Tedori River alluvial fan in Ishikawa Prefecture, Japan, where paddy fields occupy 45 % of the total area. A regional groundwater flow model simulated future groundwater levels in response to 38 climate change projections generated for each of three GCMs, using three GHG emission scenarios with the ELPIS-JP datasets. The numerical groundwater flow model consisted of a 1-D unsaturated water flow model (HYDRUS-1D) for estimating groundwater recharge and a 3-D groundwater flow model (MODFLOW). Variable parameters consisted of daily air temperature, precipitation, humidity, solar radiation, and wind speed, which influence groundwater through infiltration, evapotranspiration, snowfall, and snowmelt. Groundwater levels had both decreasing and increasing trends, depending on climate change. There were more decreasing than increasing trends, and the maximum groundwater drawdown during 2010–2090 was ~1 m. Groundwater level was most sensitive to change in rate of precipitation during the non-irrigation period. Variations of relatively low-intensity precipitation days, when daily precipitation was <10 mm, had an effect on groundwater level. These results contribute to development of adaptive and sustainable groundwater managements (e.g. land use management and pumping strategies) in the future.     

Microbial community dynamics and their contributions to organic acid production during the early stage of the ensiling of Napier grass (Pennisetum purpureum)

The study aimed to disclose the microbial community dynamics and their contributions to organic acid production during the ensiling of Napier grass. Napier grass was harvested at the vegetative growth phase and ensiled for 30 days. Three silos were opened after 1, 2, 3, 5, 7, 14, and 30 days of ensiling respectively. The intensive fermentation was observed during the initial stage of ensiling, indicated by lower pH (<4.0) on d 2 of ensiling. Lactic acid (LA) was the primary fermentation product, although acetic acid (AA) concentration rapidly increased and LA/AA concentration gradually decreased after 3 days of ensiling. The ethanol concentration was already 11.8 g/kg DM on d 1 of ensiling and then remained stable until the end of ensiling. Lactococcus was the predominant genus during the initial 2 days of ensiling, and then, it was gradually replaced by Lactobacillus. The increase in ammonia nitrogen and butyric acid concentration after 7 days of ensiling was attributed to the growth of Clostridia, which is favored by the high moisture concentration in the Napier grass. The natural ensiling of Napier grass displayed LA-type fermentation and was dominated by the fermentation of Lactobacillus and Lactococcus. Lactobacillus is mainly responsible for the LA production during the ensiling of Napier grass.     

Productivity of waterlogged and salt-affected land in a Mediterranean climate using bed-furrow systems

Waterlogging and dryland salinity in Western Australia (WA) as well as in many other parts of the world have long been recognized as major constraints to productive pastures and crops. In the late 90s, bed-furrow systems were introduced to waterlogged non-saline land in high rainfall areas of Australia. That resulted in significant yield increases of broad-acre crops through a reduction of the waterlogging. It was expected that yield gains could also be realised on waterlogged and saline land, of which more than 1 million ha is present in WA. This paper examines the productivity of crops and pasture of waterlogged and salt-affected land after the implementation of bed-furrow systems. Three sites were selected in the south western Wheatbelt of WA, with different rainfall regimes and with soil salinity ranging from none to extreme. The treatments were: pasture, cropping and raised beds (RB), no-till beds (NTB) and the Control. The distribution of salinity was mapped using an electromagnetic instrument (EM38). Pasture biomass and distribution were obtained from validated multispectral images. Grain yield and distribution were obtained from calibrated yield maps. In 4 of the 12 site-years, grain yields from the bed-furrow systems were statistically significantly compared to the Control. These were mostly associated with the site in the high rainfall region. The pasture biomass declined under the impact of summer and winter grazing and salinity. Bed-furrow systems did, in general, not generate higher grain yields for a given soil salinity compared to the Control. Relative yield - salinity relationships revealed a higher salt tolerance of the various crops compared to criteria published previously. It was also found that the interaction between waterlogging and salinity was not applicable since the timing of both issues did not coincide. Despite the grain yield gains at the high rainfall site using bed-furrow systems, cropping the low-lying salt-affected and potentially waterlogged land carries high risks. Provided these are accepted, growers with access to such land may be able to extend their cropping areas considerably. It is expected that bed-furrow systems are also beneficial in the waterlogged and salt-affected regions where topographical conditions and a precipitation surplus have created such conditions, like in some of the prairie states of North America.     

Population dynamics of arthropods in a sunn-hemp zucchini interplanting system

Zucchini, Cucurbita pepo L., is often colonized by economically important insect pests such as the striped (Acalymma vittatum Fab.) and spotted (Diabrotica undecimpunctata howardi Barber) cucumber beetles. To evaluate the impact of an interplanted cover crop on arthropods associated with zucchini, field experiments were conducted in which sunn hemp (Crotalaria juncea L.) was interplanted with zucchini as a living mulch and compared with zucchini monoculture (bare-ground) during 2009, 2010 and 2011 growing seasons. The experiment consisted also of two types of fertilizer usage including the application of synthetic or organic fertilizer in the form of chicken manure. Foliar counts of arthropods conducted on zucchini plants showed significantly lower numbers of the striped cucumber beetle in sunn hemp interplanted plots compared to bare-ground treatment plots. Also, fewer spotted cucumber beetles were found on zucchini plants in sunn hemp plots. Aphid abundances were variable during the study and significantly lower in sunn hemp treatment plots at one study site in 2009. Among predators, spiders were significantly more abundant in sunn hemp treatment plots during 2009. Fertilizer type did not have a significant effect on arthropod numbers on zucchini plants. Potential causes of arthropod population differences among the two treatments are discussed.     

Assessment of regional variation in climate on the management of dairy cow systems in Ireland using a simulation model

A dairy system simulator, Dairy_sim, was designed to assess the interactions between climate and management in spring‐calving milk production systems based on the grazing of grass pastures. The simulator comprises three main components: a grass herbage growth model, an intake and grazing behaviour model, and a nutrient demand model. The simulator was initially parameterized using the Irish National Dairy Blueprint. Sensitivity analysis indicated that the simulator was most sensitive to stocking rate, milk output per cow and nitrogen fertilizer inputs, but less sensitive to other variables. Field data from four grazing systems were used to test the simulator and it was concluded that Dairy_sim was suitable for evaluating the interaction of climate and management for rotational grazing dairy systems based on perennial ryegrass pastures with Friesian cows. The simulator, Dairy_sim, was then used to evaluate the effects of the regional climates of Ireland on system management. The results indicated that, between regions, herbage production at the same input of nitrogen may vary proportionally by 0·10 and that the length of the grazing season may vary by 0·25. It was concluded that the simulator could be a useful tool for developing region‐specific dairy production blueprints.     

Split luciferase complementation assay to detect regulated protein-protein interactions in rice protoplasts in a large-scale format

Background

The rice interactome, in which a network of protein-protein interactions has been elucidated in rice, is a useful resource to identify functional modules of rice signal transduction pathways. Protein-protein interactions occur in cells in two ways, constitutive and regulative. While a yeast-based high-throughput method has been widely used to identify the constitutive interactions, a method to detect the regulated interactions is rarely developed for a large-scale analysis.

Results

A split luciferase complementation assay was applied to detect the regulated interactions in rice. A transformation method of rice protoplasts in a 96-well plate was first established for a large-scale analysis. In addition, an antibody that specifically recognizes a carboxyl-terminal fragment of Renilla luciferase was newly developed. A pair of antibodies that recognize amino- and carboxyl- terminal fragments of Renilla luciferase, respectively, was then used to monitor quality and quantity of interacting recombinant-proteins accumulated in the cells. For a proof-of-concept, the method was applied to detect the gibberellin-dependent interaction between GIBBERELLIN INSENSITIVE DWARF1 and SLENDER RICE 1.

Conclusions

A method to detect regulated protein-protein interactions was developed towards establishment of the rice interactome.