Upland Climate Research Articles

Radial Growth Response of European Larch Provenances to Interannual Climate Variation in Poland

The present study identified the similarities and differences in the radial growth responses of 20 provenances of 51-year-old European larch (Larix decidua Mill.) trees from Poland to the climatic conditions at three provenance trials situated in the Polish lowlands (Siemianice), uplands (Bliżyn) and mountains (Krynica). A chronology of radial growth indices was developed for each of 60 European larch populations, which highlighted the interannual variations in the climate-mediated radial growth of their trees. With the aid of principal component, correlation and multiple regression analysis, supra-regional climatic elements were identified to which all the larch provenances reacted similarly at all three provenance trials. They increased the radial growth in years with a short, warm and precipitation-rich winter; a cool and humid summer and when high precipitation in late autumn of the previous year was noted. Moreover, other climatic elements were identified to which two groups of the larch provenances reacted differently at each provenance trial. In the lowland climate, the provenances reacted differently to temperature in November to December of the previous year and July and to precipitation in September. In the upland climate, the provenances differed in growth sensitivity to precipitation in October of the previous year and June–September. In the mountain climate, the provenances responded differently to temperature and precipitation in September of the previous year and to precipitation in February, June and September of the year of tree ring formation. The results imply that both climatic factors and origin (genotype), i.e., the genetic factor, mediate the climate–growth relationships of larch provenances.

Sediment generation in humid Mediterranean setting: Grain-size and source-rock control on sediment geochemistry and mineralogy (Sila Massif, Calabria)

Grain-size control on sediment composition is investigated in modern proximal sediment from the Sila Massif, where basic to felsic intrusive rocks are exposed in a Mediterranean humid–temperate upland climate. Samples were taken from small creeks and weathering profiles from three areas reflecting different bed rock compositions. Samples were separated into eleven grain size fractions from very coarse sand to clay and analyzed by (i) X-ray fluorescence for chemical composition and (ii) X-ray diffraction and Mineral Liberation Analysis for mineralogical composition. The chemical composition vs. grain size relations were modeled by compositional linear regression. Mineralogical composition of selected samples is used to substantiate the interpretations based on geochemistry. Resultsreveal a high degree of chemical weathering with chemical index of alteration (CIA) up to 92. High CIA values are restricted to the fine-grained fractions, while sand-sized sediment average at low to moderate CIA values (~60). Although strongly weathered, the three sample suites reflecting basic to felsic plutonic bed rock can be effectively discriminated across all grain-size classes using trace elements such as V, Rb, and Sr. Linear trend modeling and mineralogical data reflect similar patterns for all sample suites implying similar processes independent of source rock composition. This includes overall decrease of quartz and K-feldspar over the full grain-size range from very coarse sand to clay, which is contrasted by overall increase of sheet silicates from coarse to fine. Among the latter, increase of clay minerals strongly outpaces the increase of micas in silt to clay fractions. A more complex behavior is shown by plagioclase, which is most abundant in intermediate grain-size fractions for all sample suites. This is likely caused by initial hydrolysis along cleavage and twinning planes and subsequent breakage of plagioclase crystals into smaller fragments. Towards finer grain size, intense hydrolysis has destroyed most feldspars.

Early Eocene plant diversity and dynamics in the Falkland flora, Okanagan Highlands, British Columbia, Canada

The early Eocene fossil localities of the Okanagan Highlands in British Columbia, Canada, and Washington State, USA, span the Early Eocene Climatic Optimum, the warmest period of the Cenozoic, and reflect mild but equable upland climates (mean annual temperature 0°C). The Okanagan Highlands region has been identified as a centre of temperate plant family diversification in the northern hemisphere during the early Eocene. Here, we test the hypothesis of mid-latitude high diversity through rarefaction analysis of unbiased census collections from the Okanagan Highlands Falkland fossil locality, demonstrating levels of diversity similar to those documented at hyperdiverse Eocene sites in South America when adjusted for sample size. An explanation for this diversity may lie in the upland character of the Falkland site, as altitudinal gradients provide a mosaic of microhabitats through interacting effects of topography and climate. Fine-scale trends are also examined within the Falkland site, demonstrating a shift in plant community composition over time to a more diverse flora, although the dominant taxa persist through the section in varying levels of abundance. Intra-site patterns in plant community structure and composition are attributed to a combination of environmental factors, including disturbance and microhabitat diversity.

Developing site scale projections of climate change in the Scottish Highlands

With recent warming trends projected to amplify over the coming century, there are concerns surrounding the impacts on mountain regions. Despite these concerns, global (GCMs) and regional climate models (RCMs) fail to capture local scale-dependent controls on upland climates. A modelling framework combining climate model outputs and station data is presented and used to explore possible future changes to temperature with altitude in the Scottish Highlands. The approach was extended by modelling shifts in seasonal isotherm values associated with existing vegetation zones. To achieve this, temperature lapse rate models (LRMs) were applied to 1961–1990 baseline (BL) observed station data for selected stations in the eastern Highlands using seasonally representative lapse rate values (LRVs) derived from paired station values. Tests against 3 upland station records ranging from 663 to 1245 m indicated a credible model performance for the mean seasonal maximum (Tmax) and minimum (Tmin) BL values evaluated. Following derivation of seasonal isotherm values for the present upper limit of vegetation zones via the LRMs, selected scenario data outputs from the corresponding Hadley Centre RCM (HadRM3H) 50 × 50 km grid cells were used to project future changes to BL values via the LRMs. The findings suggest substantial shifts in the isotherm associated with each zone for the scenarios selected, with shifts in Tmin more marked than those for Tmax, although substantial uncertainties remain. Following an exploration of the results for the region, we suggest that a refinement to the approach linked to a wider modelling effort incorporating other important controlling variables for upland species could inform future management initiatives for mountain areas more generally.

Different adaptive responses of leaf physiological and biochemical aspects to drought in two contrasting populations of seabuckthorn

Two contrasting populations of seabuckthorn ( Hippophae rhamnoides L.) from western China were employed to study their differences in adaptive responses to drought. The Daofu population was from a wetter upland climate region, whereas the Dingxi populations was from a drier lowland climate region. A completely randomized design with two factors, two populations and two watering regimes (100% and 25% of the soil water holding capacity), was used. In both populations, drought significantly decreased growth and the net photosynthesis rate (A), and significantly increased the root/shoot ratio (RS), catalase (CAT), peroxidase (POD), glutathione peroxidase (GPX) and ascorbate peroxidase (APX) activities, and abscisic acid (ABA) and proline contents. Compared with the Daofu population, drought induced a greater RS value, higher CAT, GPX, and APX activities, and a higher ABA content in the Dingxi population, whereas the gas exchange traits, for example, the stomatal limitation value (LS) and intercellular CO2 concentration (Ci), were less responsive to drought in the Dingxi population. The two populations may have developed different strategies to tolerate drought, such as different pathways to dissipate excess absorbed light energy, to resist oxidative stress, and to keep water status. Such factors enable the Dingxi population to tolerate drought better than the Daofu population.

Use of the management-oriented silvopastoral model ALWAYS: Calibration and evaluation

The ALWAYS model simulates the biophysical functioning of a silvopastoral plot – here the broad-leaved tree — pasture — sheep association — and its management, according to the interactions between the different components of the system. The model was calibrated for two silvopastoral plots with contrasting soil and climate: at Lamartine in central France (wet upland climate), and at Cessous in southern France (a moderate hot and dry Mediterranean climate). The actual plot management recorded in the field was used in the model (and particularly date and number of grazing animals) and the model was run for different time series (from 2 to 100 years) depending on the process we wanted to evaluate, grass and animal production or tree growth. Models outputs were consistent with recorded data on the field and we concluded that the model can correctly simulate the behaviour of a silvopastoral plot in terms of tree growth, grass production, animal grazing and interactions between the different components. It permitted also to make consistent choices and compare different strategies of silvopastoral plots management. The improvement of some biophysical processes that are very simplified in the model is required to produce better accurate predictive values of sward or tree production. But a much more complex model will require more data for its parametrization and more time to run, precluding its use in many situations.

Crime and Politics in Colombia: Considerations for US Involvement

Very early, the state gave birth to twins--politics, the means of influencing the state, and crime, the means of avoiding the state. The three have always been related. Those with great influence on the state may not need much crime; they get their way chiefly by politics. Those with no influence are naturally drawn to state-avoidance options. For what Latin Americans call los marginados (the marginals), crime may be a rational economic choice. When it suits them, groups may combine politics and crime, using some of one and some of the other. The combination of all three, the interface of the state with politics and crime, is called corruption. Politics and crime grow from the same impulse, namely, the drive to quickly obtain money and power. Neither are wedded to violence--it's inefficient and costly--but when pushed or threatened, both quickly turn violent. Politics and crime know and understand each other quite well, forming an almost symbiotic relationship. Politics needs money to win elections and influence and pays little attention to the sources of this money (e.g., Japanese Liberal Democratic politicians and yakuza gangsters). And crime needs the protection of politics to continue its enterprises (e.g., the inability of Russian security police to solve a single assassination). At times, politics and crime semipublicly fuse into a single corrupt state, as in Slobodan Milosevic's Yugoslavia. There the fatal shooting of Arkan, a state-protected bank robber (in Sweden) and mass murderer (in Bosnia), removed one of the props of Milosevic's rule and paved the way to his electoral defeat. Country Without a State Imagine a country where the state is so weak it cannot do the minimum things a state must do--exercise sovereignty, the quality of being boss on its own turf, able to control unruly elements--and offer citizens a modicum of security and order. In such a country, politics, because it is unrestrained, easily turns violent. Crime, because it has little to fear from the state, ignores state power, intermingles with politics, and eats into state power. We need not look far for such a country. Colombia is a feast for Hobbesians (1) in the rawness of its connections between crime and politics, a rawness that long antedates Colombia's massive drug industry and the way it feeds the massive US drug appetite. Drugs may be the ultimate product of globalization. Narcotraficantes (drug traffickers) are among the greatest free-traders; they really believe in a world without borders and practice what they preach. Thanks in large part to them, crime, by dollar value, is now humankind's biggest single economic activity. Historically, Colombia has never been fully tamed. Its three Andean chains, running north-south and covering its west, are hard to transit and isolate its seacoasts (both Atlantic and Pacific) from Bogota, which lies deep in the Andes. This geographical split between seaboard and mountains was the basis of the US-sponsored breakaway of Panama in 1903 and of Conrad's 1904 novel Nostromo. (2) The volcanic soil of the Andes is rich and the upland climate is healthful, so the mountains became the coffee-growing region and most populated area. The jungled mountains also provide excellent hiding places. Slightly more than half of Colombia is lowland to the east of the Andes--the llanos, tropical, sparsely inhabited, and hard to reach. In Colombia, ground transportation is poor; you get around mostly by air. The Colombian state has never been able to rule wide areas of the country. Spain was interested only in extracting gold and silver. Creole families with latifundios (big estates) ran them as isolated mini-kingdoms. The crisis of penetration, the ability of the state to enforce its laws over all its territory, has never been overcome. (3) If you don't like the state in Colombia, you have some of the earth's best terrain to avoid it. And many dislike the Colombian state, which, in its present form, is not that old. …

Temperate Grassland Responses to Climate Change: an Analysis using the Hurley Pasture Model

The Hurley Pasture Model is process-based and couples the carbon, nitrogen and water cycles in the soil-grass-animal system. It was used to examine the responses of grasslands in southern, lowland and northern, upland climates in Britain. Short-term response to step-wise increases in CO2concentration (350 to 700 μmol mol−1) and temperature (5 °C) were contrasted with long-term equilibrium (the term ‘equilibrium’ is equivalent to ‘steady state’ throughout this paper) responses and with responses to gradually increasing [CO2] and temperature. Equilibrium responses to a range of climate variables were also examined. Three conclusions were drawn regarding the interpretation of experiments: (1) initial ecosystem responses to step-wise changes can be different in both magnitude and sign to equilibrium responses, and this can continue for many years; (2) grazing can drastically alter the magnitude and sign of the response of grasslands to climate change, especially rising temperatures; and (3) effects of changes in climate, especially temperature and rainfall, are likely to be highly site-specific. It was concluded that experiments should try to lessen uncertainty about processes within models rather than try to predict ecosystem responses directly. Three conclusions were also drawn about the operation of grasslands as carbon sinks: (1) increasing [CO2] alone will produce a carbon sink, as long as it continues to accelerate photosynthesis and increase net primary productivity; (2) by contrast, increasing temperatures alone are likely to produce a carbon source, because soil respiration is accelerated more than net primary productivity, even when assuming the same temperature function for most soil and plant biochemical processes; and (3) the net effect of projected increases in [CO2] and temperature is likely to be a carbon sink of 5–15 g C m−2yr−1in humid, temperate grasslands for several decades, which is consistent with the magnitude of the hypothesized current global terrestrial carbon sink.

A thermal comfort field survey in the cool season of Zambia

A thermal comfort field survey in Zambia, a country which experiences a tropical upland climate, is described. The survey was done in the cool season (June/July) in the city of Kitwe situated in the north of the country, using the Bedford scale. The neutral temperature was found to be 22.2 °C and the comfort zone was 19.7–24.7 °C. The survey also found that males and females have the same neutral temperature.

Thermal performance of traditional and contemporary housing in the cool season of Zambia

It is a generally held view that, in tropical countries, traditional housing is more sympathetic to the prevailing climate compared to contemporary housing. This is because the contemporary house design has typically originated from temperate climates. Empirical studies have been performed on typical traditional and contemporary houses in Zambia (in the cool season) to test whether this hypothesis holds true for Zambia, which experiences a tropical upland climate. Internal climatic conditions were measured in each house. Results show that the contemporary house performed better in the cool season than the traditional house. The external temperatures were more satisfactory than the internal temperatures. These results were further investigated using a thermal comfort survey in traditional and contemporary housing.

Thermal and Economic Implications of Passive Cooling Strategies in Low-Cost Housing in Tropical Upland Climates

This paper looks at the thermal and economic implications of passive cooling strategies in the tropical upland climate, with special reference to Zambia. The BRE—ADMIT thermal simulation computer model was used in the research. The findings are that the most thermally effective and cost efficient strategies are those related to the roof and the ceiling. It was also established that it is possible to cool the interior of houses in the tropical upland climate region to comfort levels, for a greater part of the day, using passive means alone although it is a rather expensive exercise if done as modifications to an existing house. These strategies are therefore best incorporated into the design from the onset.

Thermal performance of traditional housing in the cool season in Zambia

The thermal performance of a typical traditional house in Zambia, which experiences a tropical upland climate, is investigated by empirical measurements. Results show that the house is not comfortable in the cool season

Simulation and modeling of solar radiation in Saudi Arabia

A mathematical model is used to generate the hourly data for the total solar radiation on a horizontal surface. The generated data are based on the hourly recorded visibility data for 20 years (1970–1989). The model year technique was then applied to model the 20 years of hourly data of solar radiation into one statistically representative year. A model year of hourly data was then generated for the beam and diffuse components of solar radiation on a horizontal surface. Similarly, a model year of hourly data was also generated for the total solar radiation on tilted surfaces with different orientations with its beam, diffuse and reflected components. A simple methodology is proposed for calculating the solar radiation on vertical surfaces, based on a solar impact factor (SIF). Monthly means and daily totals of hourly sums for each month of the year are discussed. The hourly data of solar radiation for a typical day for each month of the year are presented. The data were generated for the four climatic zones of Saudi Arabia, the hot-dry (Riyadh), the warm-humid (Jeddah), the maritime inland desert climate (Dhahran) and the upland climate zone (Taif). The accuracy of the results is discussed and found to be above 90% representative.

Operational research study of forage conservation systems for cool, humid upland climates. Part 2: Comparison of hay and silage systems

The improved operational research model described in Part 1 of this paper is exploited to compare the economics of hay and silage systems for climatically different areas of Scotland. Both field-dried and barn-dried hay are explored, and the silage systems studied include unwilted-clamp silage, wilted-clamp silage and baled silage. Also, high cost, high capacity systems are compared with low cost, low capacity systems for each method. Each system is costed and compared in terms of net value of forage produced. Results of simulation and feed evaluation runs for a range of grassland areas suggest that the economics of silage as a conservation method are nearly always more favourable than hay under Scottish climatic conditions. The economics of wilted silage are much better than unwilted silage. Silage systems should be based on a precision chop forage harvester for small farms, and on big bales rather than a flail forage harvester for small farms. Only on small farms in drier East of Scotland areas are the economics of haymaking comparable to silage, and here there is little to choose between field drying and barn drying. The importance of selecting a system with sufficient capacity for the quantity of crop to be conserved is also demonstrated. Parts of the model which could be further developed are discussed. Opportunities for further exploitation of the model in its present form have also been identified.

Operational research study of forage conservation systems for cool, Humid upland climates. Part 2: Comparison of hay and silage systems

The improved operational research model described in Part 1 of this paper is exploited to compare the economics of hay and silage systems for climatically different areas of Scotland. Both field-dried and barn-dried hay are explored, and the silage systems studied include unwilted-clamp silage, wilted-clamp silage and baled silage. Also, high cost, high capacity systems are compared with low cost, low capacity systems for each method. Each system is costed and compared in terms of net value of forage produced. Results of simulation and feed evaluation runs for a range of grassland areas suggest that the economics of silage as a conservation method are nearly always more favourable than hay under Scottish climatic conditions. The economics of wilted silage are much better than unwilted silage. Silage systems should be based on a precision chop forage harvester for small farms, and on big bales rather than a flail forage harvester for small farms. Only on small farms in drier East of Scotland areas are the economics of haymaking comparable to silage, and here there is little to choose between field drying and barn drying. The importance of selecting a system with sufficient capacity for the quantity of crop to be conserved is also demonstrated. Parts of the model which could be further developed are discussed. Opportunities for further exploitation of the model in its present form have also been identified.

Operational research study of forage conservation systems for cool, humid upland climates. Part 1: Description of model

An improved operational research model is described for studying the economics of forage conservation systems, particularly for cool, humid, upland climates. This covers the whole process, from growth of grass, through all the conservation operations, to evaluation of conserved forage for feeding ruminants. Sub-models simulate growth of grass, drying and rewetting of swaths in the field after cutting, mechanical field operations, crop losses in the field and in storage, and drying in a barn, in relation to historical weather data. Forage is evaluated using a standard dairy cow ration formulation procedure, adapted to take account of variations in intake with quality of forage. Conservation can be represented as field-dried hay, barn-dried hay, wilted silage and direct-cut silage.

Operational research study of forage conservation systems for cool, humid upland climates. Part 1: Description of model

An improved operational research model is described for studying the economics of forage conservation systems, particularly for cool, humid, upland climates. This covers the whole process, from growth of grass, through all the conservation operations, to evaluation of conserved forage for feeding ruminants. Sub-models simulate growth of grass, drying and rewetting of swaths in the field after cutting, mechanical field operations, crop losses in the field and in storage, and drying in a barn, in relation to historical weather data. Forage is evaluated using a standard dairy cow ration formulation procedure, adapted to take account of variations in intake with quality of forage. Conservation can be represented as field-dried hay, barn-dried hay, wilted silage and direct-cut silage.

Species Number and Endemism: The Galápagos Archipelago Revisited

Regression analyses to determine plant species number are repeated for the Galápagos Islands with new data. The multiple curvilinear regression gives the best prediction of species number, with island area making the only significant contribution. The proportion of species endemic to the Galápagos is highest in the arid, transition zone and on small islands, and lowest in the littoral and mesic zones. This is explained in terms of zone-specific immigration and extinction rates and the very recent appearance of moist upland climates in the archipelago.

Meteorological observations on Dun Fell, a mountain station in Northern England

AbstractMeteorological observations have been kept lor three years 1937–40 on the exposed summit of Dun Fell in the Northern Pennines, including a continuous record of temperature. In a semi‐maritime climate this mountain station at 2,735 ft. is well above the tree‐line and conditions are at times severe. Estimates of the longer‐period averages are made for several climatic elements and compared with those from summit stations elsewhere. It is emphasised that over longer periods of time considerable variations in the upland climate are likely to occur as a result of small changes in the average distribution of pressure and that these will react considerably upon the vegetation. Although this record was initiated for other reasons and is unpretentious in scope it may be added that this is the first series of “mountain” observations to become available in England.