Greater Amounts Of Precipitation Research Articles

INFLUENCE OF ATMOSPHERIC PRECIPITATIONS ON THE RUN OF THE PUTIL RIVER

Research of precipitation, water balance of river basins, and the impact of precipitation on river runoff remain relevant in the context of global and regional climate change. Nowadays, many scientific research all over the world are devoted to the research of the problem of river runoff change under the influence of climatic factors. This kind of research has been developing strongly in Ukraine in recent decades. In particular, they concern the rivers of the Ukrainian Carpathians. The basin of the river Putyla to the line of the village of Putyla has an area of 181 km2. It is located in the south-eastern part of the Carpathian and characterized by a significant influence of warm rains on the formation of water runoff. The average annual runoff is characterized by rather complex patterns of change both in time and space. There are periodic, cyclical and unidirectional changes that occur under the influence of a complex system of factors. Climate is a major factor of the water change. Thus, the research of the average runoff of the Putila River has different aspects.To determine the effect of precipitation on river runoff, the method of comparing difference-integral curves of annual runoff and precipitation, as well as water-balance methods are used. Long-term changes and intra-annual distribution of precipitation, in particular rainfall, according to the observations of the meteorological station Selyatyn were analyzed. We constructed a differential integrated curve of modular coefficients of the average annual precipitation in the Putil district. It clearly reflects the cyclical changes in precipitation. Long-term changes and intra-annual distribution of water runoff in the Putyla River also were analyzed. During the observation period, periods of long-term fluctuations of the average annual precipitation were revealed. The average annual rainfall is 842.9 mm. The annual course is stable, ie the greatest amount of precipitation falls in the summer, when there are intense thunderstorms and showers, the least – in winter. Based on the data of hydrological observations, the average long-term value of water consumption according to GP Putila is 2.47 m3/s. We calculated the coefficient of variability (variation). The coefficient of variation for average costs is 0.21 (21%), and for precipitation – 0.7 (7%). The connection between precipitation and runoff was established. We have built a comprehensive schedule of annual distribution of precipitation and costs of the Putyla River for 2010. You can see that in the spring due to snowmelt there is an influx of water and there is a spring flood. It is known that 2010 in Putilsky district was full of water. The reduction of water consumption in the Putyla River in the cold period of the year with a decrease in precipitation is also observed. Graph of the dependence of the runoff of the Putyla River on precipitation in the village of Selyatyn showed a fairly clear relationship between the variable values of runoff and precipitation (the coefficient of variation is 0,66). The feeding structure of the Putyla River is mixed. The main share is occupied by rain, less - snow and groundwater.
 Key words: climate change, precipitation, runoff, rivers, long-term changes in runoff, intra-annual distribution of precipitation and runoff, Putyla river.

Feather corticosterone reveals developmental challenges in a long‐term study of juvenile northern spotted owls

Abstract Corticosterone is a steroid hormone integral to a variety of physiological pathways and is strongly associated with the vertebrate stress response. In avian species, circulating corticosterone is sequestered into developing feathers and is used as an indicator of energy allocation during feather growth and widely applied in conservation physiology. The northern spotted owl Strix occidentalis caurina is a federally threatened old‐growth forest obligate of conservation concern endemic to the Pacific Northwest of the United States and Canada. The effects of landscape characteristics and individual variation on early development in spotted owls remain unstudied despite long recognition of this knowledge gap and its potential importance to species conservation. We quantified corticosterone concentrations in 4,720 feathers from 1,056 juvenile spotted owls across seven study areas between 2001 and 2017. We used an information‐theoretic approach to examine the environmental and individual factors related to feather corticosterone in juvenile spotted owls as an indicator of challenges during early development. Feather corticosterone was positively related to temperature and precipitation, and negatively related to juvenile mass at banding. We found strong support for an interaction between mass and precipitation, with greater amounts of precipitation being associated with higher levels of feather corticosterone in lighter juveniles. The temperature and precipitation metric with the strongest relationship with feather corticosterone occurred during the fledging period, suggesting that this period presents an energetic challenge for juvenile spotted owls. Greater juvenile mass decreased the effect of precipitation, suggesting that greater mass was important for juveniles to maintain homeostasis during fledgling. Feather corticosterone in juvenile spotted owls provided insights to the challenges faced during early development, adding to our understanding of spotted owl life history and potential for population recovery. A free Plain Language Summary can be found within the Supporting Information of this article.

Dynamics of the long-term distribution of precipitation in the eastern regions of Kazakhstan

Precipitation is the most variable meteorological phenomenon in time and space. The study of the regime of long-term fluctuations of precipitation is one of the most important problems. Spatial heterogeneity of precipitation was considered by many authors. The heterogeneity of the precipitation field is determined by the combined influence of large-scale atmospheric processes and the nature of the underlying surface, especially the complex relief. These factors determine the conditions for the distribution of precipitation acting in close interconnection in space and time. The article discusses the dynamics of the long-term distribution of precipitation in the eastern regions of Kazakhstan. A feature of the climatic distribution of precipitation was described, factors influencing the climatic distribution were identified, and the conditions for repetition and macroscopic exposure in the most humid and scarce periods were determined. Also, the matrix of paired correlation coefficients was determined during periods of abnormal humidity and deficit. The article describes the features of the climatic distribution of precipitation in the eastern part of Kazakhstan. The factors affecting the climatic distribution of precipitation are presented, and the recurrence and macro circulation of excessively wet and deficient periods are considered. The matrix of paired correlation coefficients in abnormally wet and deficient periods has been determined. Mathematical, statistical analyzes and methods of climatic variations were widely used in meteorology to analyze the dynamics of precipitation. During the study period 1930-2017 the annual precipitation at Semey, Oskemen, Aygoz, Zaisan stations in the eastern regions of Kazakhstan decreased by about 8–20 mm. The greatest amount of precipitation was observed in summer (428 mm), while the smallest amount was observed in January and February (7–13 % of the annual norm). In the cold season the amount of precipitation was below 55 % of the average annual norm, and the amount of precipitation in a wet year is 50% lower than the annual norm. The season of cold and wet weather began in East Kazakhstan in the 1940s, and rainfall over the year increased by more than 60 %. In 1936-1980 in East Kazakhstan there was a decrease in form W, an increase in forms C, E. In the period 1981-2008. an increase in the frequency of form III and a decrease in forms C, E increased the amount of precipitation at Semey station, reduced the amount of precipitation at Ayagoz station, and led to a uniform distribution of precipitation at Oskemen and Zaisan stations.

Life history responses of two ephemeral plant species to increased precipitation and nitrogen in the Gurbantunggut Desert.

Precipitation change and nitrogen deposition are not only hot topics of current global change but also the main environmental factors affecting plant growth in desert ecosystems. Thus, we performed an experiment of increased precipitation, nitrogen, and precipitation plus nitrogen on the ephemeral annual species Nepeta micrantha and Eremopyrum distans in the Gurbantunggut Desert. We aimed to determine the life history responses of N. micrantha and E. distans to environment changes, and the germination percentage of the offspring (seeds) was also tested in the laboratory. The results showed that increased nitrogen and precipitation plus nitrogen increased the growth of both plant species, whereas increased precipitation inhibited the growth of N. micrantha but increased the growth of E. distans. This differential response of these two species to precipitation and nitrogen also affected the germination of their offspring. In response to increased nitrogen and precipitation plus nitrogen, the germination percentage of the offspring produced by two species decreased in conjunction with the plants exhibiting high reproduction, which may prevent overcrowding during the following year; however, the N. micrantha plants produced more nondormant offspring in conjunction with low reproduction under relatively greater amounts of precipitation, and N. micrantha offspring could occupy their habitat via rapid germination in suitable environments. Therefore, with increased precipitation and nitrogen deposition, these differences in offspring dormancy may affect their ecological niche in the community.

Soil carbon pools in two natural grasslands of Serbian highlands

Grasslands are a major player in the global carbon cycle, although carbon stocks in grasslands are influenced by human activities and natural disturbances. The aim of this study is to determine differences in carbon stock on two test areas of grassland ecosystem in the highlands of Stara Planina and Zlatar Mountains (Serbia). The investigated sites are natural mountain grasslands of the same vegetation community (Agrostietum capillarisPavl. 1955) and soil type (Umbric Leptosol (Dystric) and Haplic Cambisol (Dystric)), but with different grazing intensity. Aboveground and belowground biomasses were measured in each sample plot, and soil was sampled at fixed depths of 0-10, 10-20 and 20-40 cm. The estimation of C stock and the rate of soil C accumulation were determined by the Tier 2 method IPCC (2003). Carbon mineralization potentials were determined via sequential incubation procedure in the laboratory conditions. According to the obtained results, the greater amount of precipitation on Mt. Stara Planina resulted in a greater accumulation of aboveground biomass, which was subjected to a greater decomposition in situ, thus showing a lower amount of PMC in vitro. In addition, potentially mineralizable carbon (PMC) among the sample plots from both sites indicates that the mineralization of soil organic matter was more influenced by the factors related to the soil characteristics, climatic conditions and grazing.

Nature of extreme precipitation over Ukraine in the 21st century

The article examines the state of precipitation over the territory of Ukraine over recent decades. Through the example of central months of the seasons differences in monthly and average daily precipitation amounts for the period of 2000-2014 are shown. Within the most territory of Ukraine summer precipitation is almost twice as high as spring and autumn one. During all seasons the greatest amount of precipitation is observed in the Carpathian region. Distribution of average long-term precipitation values over the rest of the territory coincides in spring, summer and autumn: the highest precipitation values are observed in the western and north-western parts and decrease to the south-east.
 The article studies a yearly precipitation rate at low-land and mountain meteorological stations. It proposes to separate criteria of precipitation extremality depending on the regions. All extreme daily precipitation can be divided into the following categories: > 20-30 mm / day, > 30-50 mm / day, > 50 mm / day. Each category of extreme precipitation has its a certain economic risk, but the third class can cause not only economic risks, but also risks associated with human life and activities. The distinct feature of the present-day precipitation consists in redistribution of precipitation in the middle of the months, when a daily precipitation rate increases together with intervals between heavy rains.
 In order to analyze the changes of precipitation regime, the approach of dividing the rates of monthly precipitation amount by the rates of extreme and non-extreme precipitation is proposed. A comparative analysis of daily precipitation in different seasons and over different climatic periods was also carried out. The article studies the proportion of daily precipitation of up to 15 mm and the one exceeding 15 mm forming a part of monthly rates of precipitation over the territory of Ukraine. In January, rainfalls exceeding 15 mm make up from 5-10 % of the total amount of monthly precipitation, except the Carpathian region and the southwestern regions of Ukraine where those exceed 20-25 %. In spring, the amount of rainfalls increases and its percentage of the monthly precipitation amount is around 20 % over most of the regions. Until summer, the amount of rainfalls increases and in July its percentage is 50-70 %. Until autumn, the amount of those starts decreasing, however, the percentage of rainfalls is almost twice as high as in spring, and for most of the regions it is about 30-40 %. Such breakdown of the monthly precipitation rates into two components allows determination during a period in question of precipitation amounts we have each month.
 The maximum daily precipitation amounts serve as an important indicator of the precipitation regime which shows the potential danger from extreme precipitation. For different regions the threshold values of the upper limit of rainfalls taken as a maximum daily value for the period of 2000-2014 differ. In winter and spring time, the limit of rainfalls amount per day usually hits 20-30 mm for the most territory of the country. At the same time there are certain areas where the limit values of the daily rainfalls rate reach 40-50 mm. The most significant rainfalls are observed in summer. Despite the fact that the territory of such rainfalls is quite patchy, nevertheless, those areas where precipitation rate over one day may reach 70 mm are the most vulnerable and have high risks for human life and activities. In autumn, the threshold values are 30-40 mm.
 The breakdown of the rates of monthly precipitation amount into extreme and non-extreme ones allows determination in future of whether the precipitation regime changes because of extreme or non-extreme values. Also, in the long run, a comparative analysis of the rates of showers and weak rainfalls in the late 20th and early 21st centuries can be carried out and a tendency of precipitation regime seasonal change over the next decade can be obtained which will help us to identify vulnerable regions suffering from extreme precipitation rates.

Impact of climat changes on agro-climatic indices of the vegetative period of main agricultural crops

Article in question investigates indicators of the moisture-temperature regime for the period of 1986 - 2005 (base period) and compares them to their expected changes calculated for different scenarios of climate change GFDL-30 %, A1B, A2, RCP4,5 and RCP8,5 for the period of 2021 - 2050 on the territory of Ukraine. Calculations reviled that most abrupt changes in moisture-temperature indicators in different soil-climatic zones of Ukraine can be expected in case of scenarios GFDL-30 %, А1В and А2. In case of scenarios of climate change RСР4,5, RСР8,5 thermal indicators are expected to be at the level of multilevel averages in all natural and climatic zones of Ukraine, except for Southern Steppe, where they are expected to grow. The greatest changes in all areas are expected under scenario GFDL-30 %, and they will increase from north to south. Under scenario А1В the greatest difference between calculated values and average multi-year values will be observed in the Forest-Steppe zone and in the Southern Steppe. Under scenarios RCP4,5 и RCP8,5 significant changes in the temperature regime are predicted only for the south and east of Ukraine. At the same time, according to the scenario of RCP4.5, a significant increase in seasonal winter air temperatures is forecasted. Analysis of the results of calculations for different climatic scenarios of water availability indicators for different natural and climatic zones of Ukraine for the period from 2021 to 2050 reviled that the most drastic changes in the climatic parameters of humidification are expected in the case of the scenarios GFDL-30 %, A1B and A2. In case of climate change scenarios RCP4.5, RCP8.5, no quick changes in the distribution of precipitation over the territory of Ukraine should be ex-pected. The greatest amount of precipitation for the year and in average for the seasons of the year is projected for the western regions of the country, the least one - for the southern regions. At the same time, for most regions the trend to increase the amount of precipitation is most likely in the case of the development of the GFDL-30 %, A1B and A2 scenarios. However, according to the scenarios RCP4.5 and RCP8.5, rainfall is expected to decline for the year as a whole and especially in the summer season in comparison with the actual for 1986 - 2005.

Insolação, radiação solar global e radiação líquida no Brasil

O presente trabalho teve como objetivo caracterizar a distribuição espacial e temporal da insolação, radiação solar global e radiação líquida no Brasil, bem como o potencial regional do país em relação a esses elementos climáticos. Mapas mensais e anuais, gerados a partir de dados medidos e estimados de 204 estações meteorológicas distribuídas por todo o território brasileiro, bem como diagramas temporo-espaciais, derivados de transectos escolhidos nas direções sul-norte e oeste- -leste, permitiram representar as tendências das variações dos elementos climáticos estudados e sua relação com atributos regionais. Na elaboração dos mapas foram considerados aspectos geográficos (vegetação, hidrografia, orografia e geomorfologia) e climáticos (nebulosidade e chuva). Na ausência de dados de radiação solar global medidos, empregou-se a equação de ANGSTRÖM de 1924, que utiliza dados de insolação. A estimativa do balanço de radiação (radiação líquida) foi realizada a partir da fórmula estabelecida por LINACRE de 1967. Na região norte, a insolação é menor nas áreas com maiores totais de precipitação, como a foz do Rio Amazonas e o estado do Amapá. A radiação solar global apresenta valores altos e pouca variação, devido à transmissividade elevada da atmosfera. Em virtude da uniformidade do relevo e albedo, a radiação líquida apresenta também valores elevados. No Nordeste, os valores elevados de insolação são explicados pela baixa nebulosidade, principalmente no sertão. Os máximos de radiação líquida ocorrem no litoral. Na região centro-oeste, nas áreas onde ocorre maior quantidade de precipitação, os valores de insolação são baixos. A radiação global e radiação líquida apresentam quantidades semelhantes àquelas da região norte. No sudeste brasileiro, a distribuição da insolação é condicionada aos fatores relevo, nebulosidade e precipitação. A radiação global e a radiação líquida distribuem-se mais irregularmente devido também à nebulosidade, como é o caso da bacia do Rio Doce, onde os valores são mais baixos. Para a radiação líquida também deve ser considerado o albedo, que varia conforme o uso da terra. Na região sul, todos os elementos sofrem o efeito orográfico, que produz um gradiente no sentido do litoral para o interior. A partir da distribuição espacial da insolação, radiação global e radiação líquida pode-se verificar a potencialidade do Brasil quanto à energia solar, nos aspectos qualitativo, quantitativo e consuntivo. Esta pesquisa pode servir de subsídio para o planejamento agrícola, no que diz respeito ao estabelecimento do zoneamento agroclimático e previsão de safras, e para o planejamento urbano, na melhor adequação do balanço de radiação, levando em consideração a ordenação do crescimento vertical e incremento de áreas verdes.

Prinos zrna hibrida kukuruza u različitim gustinama setve

Field trials with 12 maize hybrids belonging to FAO maturity groups 500, 600 and 700 were established under the agro environmental conditions of Smederevo in 2010 and 2011 to analyse grain yield and moisture content at different plant densities. The hybrids were sown in two independent trials in the two years at 51,000 and 62,000 plants ha-1, respectively, in a randomised block design with three replications. More favourable maize growing conditions i.e. more moderate air temperatures during the growing season, a more even distribution of precipitation and more rainy days were recorded in 2010 than in 2011, which had much lower precipitation amounts, particularly during July and August i.e. critical development stages (flowering and fertilization) of these hybrids. Grain yield of all maize hybrids was higher in 2010, mostly as the result of greater amounts of precipitation and their more even distribution during the growing season. In both years, significantly higher grain yields were obtained by FAO 600 maize hybrids. Grain yield in 2010 was significantly higher at the higher plant density in FAO 500 hybrids, as opposed to FAO 600 hybrids, which showed no significant difference in grain yield across plant densities. Grain moisture content at harvest did not significantly differ between plant densities in either year. Somewhat higher values for grain moisture at harvest in 2010 were recorded for FAO 600 hybrids. In 2011, there were no significant differences in grain moisture content among hybrids, nor between plant densities, mostly due to the very low amount of precipitation in the second part of the growing season.

INFLUENCE OF DEM IN WATERSHED MANAGEMENT AS FLOOD ZONATION MAPPING

Despite of valuable efforts from working groups and research organizations towards flood hazard reduction through its program, still minimal diminution from these hazards has been realized. This is mainly due to the fact that with rapid increase in population and urbanization coupled with climate change, flood hazards are becoming increasingly catastrophic. Therefore there is a need to understand and access flood hazards and develop means to deal with it through proper preparations, and preventive measures. To achieve this aim, Geographical Information System (GIS), geospatial and hydrological models were used as tools to tackle with influence of flash floods in the Kingdom of Saudi Arabia due to existence of large valleys (Wadis) which is a matter of great concern. In this research paper, Digital Elevation Models (DEMs) of different resolution (30m, 20m,10m and 5m) have been used, which have proven to be valuable tool for the topographic parameterization of hydrological models which are the basis for any flood modelling process. The DEM was used as input for performing spatial analysis and obtaining derivative products and delineate watershed characteristics of the study area using ArcGIS desktop and its Arc Hydro extension tools to check comparability of different elevation models for flood Zonation mapping. The derived drainage patterns have been overlaid over aerial imagery of study area, to check influence of greater amount of precipitation which can turn into massive destructions. The flow accumulation maps derived provide zones of highest accumulation and possible flow directions. This approach provide simplified means of predicting extent of inundation during flood events for emergency action especially for large areas because of large coverage area of the remotely sensed data.

Long-term trends and variability of total and extreme precipitation in Thailand

Based on quality-controlled daily station data, long-term trends and variability of total and extreme precipitation indices during 1955–2014 were examined for Thailand. An analysis showed that while precipitation events have been less frequent across most of Thailand, they have become more intense. Moreover, the indices measuring the magnitude of intense precipitation events indicate a trend toward wetter conditions, with heavy precipitation contributing a greater fraction to annual totals. One consequence of this change is the increased frequency and severity of flash floods as recently evidenced in many parts of Thailand. On interannual-to-interdecadal time scales, significant relationships between variability of precipitation indices and the indices for the state of El Niño–Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) were found. These results provide additional evidence that large-scale climate phenomena in the Pacific Ocean are remote drivers of variability in Thailand's total and extreme precipitation. Thailand tended to have greater amounts of precipitation and more extreme events during La Niña years and the PDO cool phase, and vice versa during El Niño years and the PDO warm phase. Another noteworthy finding is that in 2011 Thailand experienced extensive flooding in a year characterized by exceptionally extreme precipitation events. Our results are consistent with the regional studies for the Asia-Pacific Network. However, this study provides a more detailed picture of coherent trends at a station scale and documents changes that have occurred in the twenty-first century, both of which help to inform decisions concerning effective management strategies.

Incidence of grape anthracnose on different VITIS labrusca and hibrid cultivars and rootstocks combination under humid subtropical climate

Anthracnose is a severe disease present in several grape production areas; it is considered a tropical disease. In South Brazil, high relative humidity and other conditions favor the occurrence of fungal disease in vineyards. The objective of this study was to evaluate the anthracnose incidence progress in grape leaves in three scion cultivars (Concord, Bordo and BRS Carmem) in combination with three rootstock (1103 Paulsen, VR 043–43 and IAC 766), in regional climatic conditions favorable for disease development. The experiments were carried out on ridges with semi-trellis system. The experimental design was randomized blocks, with split plots, with 4 replications and 4 plants per plot. The plots were represented by 9 different combinations. Disease incidence was assessed at two week-interval from September to March (2010/2011, 2011/2012, and 2012/2013). At each sampling, disease was assessed 10 leaves of a same shoot of 6 plants for each cultivar/rootstock combination, for a total of 54 plants. All cultivar-rootstock combinations showed disease symptoms with highest disease incidence coinciding with the greatest amount of precipitation. Based on the relative area under the disease progress curve (AUDPC), the anthracnose incidence showed differences between seasons. Differences between rootstocks and rootstock/cultivar combinations were observed during the first and third season, but there was no consistency between the seasons, indicating that the variation in disease progress could be due to other factors, including as weather conditions, age of the vineyard and inoculum pressure.

Dynamic Pore Scale Modeling of Asphaltene Deposition in Porous Media

Asphaltene deposition in porous medium is one of important factors in reducing the productivity of oil reservoirs. Reduction of permeability is the main factor, which is also due to reduced pores size or complete closure of them. The authors simulate phase one flow of oil in porous medium using a dynamic pore scale network model. Also asphaltene deposition process is considered based on a scaling equation. Because the greatest amount of precipitation occurs at bubble point pressure condition, we considered boundary conditions of the model in this pressure. The hypothetical model is only a very small element of a real reservoir rock therefore we assumed constant temperature in this process, consequently the main reason of asphaltene precipitation is pressure changes in the pores. Permeability reduction simulated was based on these steps: pore and throat pressure changes were due to fluid flow through the network and asphaltene deposited according to scaling equation. Applying a material balance for each pore/throat gives the volume reduction of pores/throats according to the deposited asphaltene. Due to this change in pores size permeability and porosity of the model is calculated. Repeating these steps over the time gives effect of asphaltene deposition on the primary properties of porous medium.

The impact of land use and season on the riverine transport of mercury into the marine coastal zone.

In Mediterranean seas and coastal zones, rivers can be the main source of mercury (Hg). Catchment management therefore affects the load of Hg reaching the sea with surface runoff. The major freshwater inflows to the Baltic Sea consist of large rivers. However, their systems are complex and identification of factors affecting the outflow of Hg from its catchments is difficult. For this reason, a study into the impact of watershed land use and season on mercury biogeochemistry and transport in rivers was performed along two small rivers which may be considered typical of the southern Baltic region. Neither of these rivers are currently impacted by industrial effluents, thus allowing assessment of the influence of catchment terrain and season on Hg geochemistry. The study was performed between June 2008 and May 2009 at 13 sampling points situated at different terrain types within the catchments (forest, wetland, agriculture and urban). Hg analyses were conducted by CVAFS. Arable land erosion was found to be an important source of Hg to the aquatic system, similar to urban areas. Furthermore, inflows of untreated storm water discharge resulted in a fivefold increase of Hg concentration in the rivers. The highest Hg concentration in the urban runoff was observed with the greatest amount of precipitation during summer. Moderate rainfalls enhance the inflow of bioavailable dissolved mercury into water bodies. Despite the lack of industrial effluents entering the rivers directly, the sub-catchments with anthropogenic land use were important sources of Hg in the rivers. This was caused by elution of metal, deposited in soils over the past decades, into the rivers. The obtained results are especially important in the light of recent environmental conscience regulations, enforcing the decrease of pollution by Baltic countries.

Modern vegetation, pollen and climate relationships on the Mediterranean island of Cyprus

This research investigates patterns of plant species distributions, modern pollen deposition, and climate on the island of Cyprus in the eastern Mediterranean, and explores the potential for using these modern pollen–vegetation–climate relationships for paleoenvironmental interpretation. Vegetation and pollen data were collected at 56 locations along elevational gradients from the southern coast across the Troodos Mountains, to the Kyrenia Range, and to the northern coast of Cyprus. Elevation, mean annual precipitation and mean annual temperature were interpolated for each sample locale. Discriminant analysis, cluster analysis, non-metric multi-dimensional scaling and indices of plant-pollen fidelity and dispersibility are used to characterize the vegetation and pollen of Cyprus.The main vegetation types in Cyprus — oak forests, pine forests, orchards, and coastal scrub and salt lake vegetation can be distinguished in modern pollen samples; samples from disturbed garigue vegetation could not be separated from surrounding vegetation types. Pollen taxa demonstrate clear relationships with climatic variables. Pinus, Cyperaceae, Cistus, Quercus and Prunus are found associated with greater amounts of precipitation and higher elevations. Higher temperatures are linked particularly to Cupressaceae, Olea, Cerealia-type, Liguliflorae, and Chenopodiaceae pollen. The majority of the pollen taxa show moderate to moderately high fidelity, signifying the close link between the vegetation of Cyprus and its pollen. Many pollen taxa also reflect high dispersibility, which in some cases demonstrates over representation in the pollen rain. The relationships between the main modern pollen taxa of Cyprus and broad climatic variables can provide the basis for interpreting paleoenvironmental records.

A fine line – endophytes or pathogens in Arabidopsis thaliana

Fungal endophytes were isolated in 2007 and 2008 from healthy Arabidopsis thaliana, growing in its natural environment in Braunschweig, Germany. In 2007, the predominant isolate was Leptosphaeria maculans. In 2008, the assemblages of isolates differed, with not even one isolate of L. maculans. Greater amounts of precipitation may explain the abundance of L. maculans in 2007, since its infection requires rainfall. In 2008, the main genera isolated were Phomopsis, Phoma and Coniothyrium. Following inoculation into axenically cultured A. thaliana on agar medium – conditions stressful for the host, but favorable for the endophytes – only three of eight isolates colonized asymptomatically: Plectosphaerella cucumerina and two Coniothyrium spp., emphasizing the delicate balance between fungal virulence and host defense. L. maculans, P. cucumerina and the Coniothyrium spp. could be used for investigating the molecular basis of interactions between A. thaliana and fungal endophytes that colonize A. thaliana in its natural environment.

Modeling Pleistocene local climatic parameters using macrophysical climate modeling and the paleoecology of Pleistocene megafauna

Application of Macrophysical Climate Modeling to sites containing specimens with reliable radiocarbon dates of the extinct giant beaver, Castoroides ohioensis, allows an examination and comparison of their climatic parameters and the establishment of a rudimentary climatic envelope for this extinct species. Two climatic parameters were examined for this study, temperature and precipitation. An analysis of eight sites with the giant beaver indicates that the species was cold tolerant and lived under colder January and July temperatures than exist at these sites today. At five of the eight sites the model suggests there was a shift in seasonal precipitation from the greatest amount of precipitation taking place during the late summer-fall in the Pleistocene to spring-early summer today.

A scaling analysis of soil moisture–precipitation interactions in a regional climate model

The University of Oklahoma’s Advanced Regional Prediction System (ARPS) was used to examine the impacts of varying mean soil moisture and model resolution on the magnitude and frequency of precipitation events in the U.S. Central Plains and to determine whether modeled soil moisture and precipitation fields exhibit scale invariance using the statistical moments. It was found that high soil moisture resulted in greater precipitation amounts and a higher frequency of events, suggesting the occurrence of a positive soil moisture–precipitation feedback. The scaling analysis performed on cumulative precipitation determined that these fields did not exhibit signs of self-similarity and, therefore, statistical properties cannot be predicted at other resolutions. The scaling properties of soil moisture were highly variable in time which has important implications for the use of remotely sensed data, as scaling properties from 1 day cannot necessarily be applied to subsequent days.

Combined Effects of the Southern Oscillation Index and the Pacific Decadal Oscillation on a Stochastic Daily Precipitation Model*

AbstractThe combined effects of the Southern Oscillation index (SOI) and the Pacific decadal oscillation (PDO) on a second-order Markov chain mixed exponential daily precipitation model were determined for 15 stations in Nevada, Arizona, New Mexico, and Washington. The linkage between these monthly indices and daily precipitation was investigated by perturbing logits of Markov chain transition probabilities and the mean of the mixed exponential distribution by linear functions of a time-lagged SOI and concurrent PDO. The combination of linear coefficients and lags that resulted in the maximum log-likelihood functions was identified, and the Akaike information criterion (AIC) was used to determine the best model. The SOI effect was consistent with previous studies in that negative SOI (El Niño) leads to more frequent precipitation and greater amounts of precipitation given a wet day in Nevada and the Southwest, with the opposite effect in the northwest. SOI and PDO interactions were most significant for the Nevada stations where a positive PDO increases both the probability of a wet day for three transition probabilities and also increases the mean of wet-day precipitation. The PDO had little effect for the monsoonal (Arizona and New Mexico) stations except for Hobbs, New Mexico, where a positive PDO would increase the mean depth on a wet day. The Washington stations showed an increase in the frequency and mean depth of precipitation given a positive SOI, but PDO had little effect. Identification of combined SOI–PDO effects allows more realistic simulations of daily precipitation and provides insight into the reliability of short records.

Estimating understory vegetation response to multi-nutrient fertilization in Douglas-fir and ponderosa pine stands

Models were developed to predict understory vegetation response to multi-nutrient fertilization at six conifer-forested stands in the inland Northwest United States. Equations are presented to estimate how fertilization as well as other factors impacting understory production in the inland Northwest change total understory vegetation production and the production of three individual lifeforms (shrubs, forbs, and grasses and grass-likes). Overstory stand density was found to have the greatest impact on understory production, and regardless of factors such as fertilization or precipitation, large stand densities will limit understory production. At lower stand densities, multi-nutrient fertilization as well as greater amounts of precipitation will increase understory production. These factors were also found to be synergistic; thus, greater amounts of precipitation increase the effects of multi-nutrient fertilization on understory production. For sites of the same stand density, Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] was shown to have a greater negative impact on understory production than ponderosa pine (Pinus ponderosa Dougl. ex Laws.). The models predict that multi-nutrient fertilization of ponderosa pine stands will produce increases in understory production across a broader range of stand densities.