Vulnerability assessment of Angat water reservoir to climate change

Global warming due to an anticipated doubling of carbon dioxide concentration in the atmosphere is expected to alter the earth's climate system within the next century. The potential changes in the climate system could affect hydrological cycles and processes. Possible impacts of climate change on water resources should be assessed to evaluate probable adaptation measures. In the Philippines, a preliminary assessment of the vulnerability of water resources to climate change and variability was undertaken. For this particular study, the Angat Reservoir was chosen as the study area. Because of its socioeconomic importance, it is useful to assess its vulnerability to climate change. A rainfall-runoff simulation model, WATBAL, was used to determine the effect of temperature and rainfall changes, based on CO₂ doubling, on inflow to the reservoir. Climate change scenarios developed from results from three general circulation models and incremental changes were used. The results showed that changes in temperature and rainfall could affect runoff either positively or negatively. Using the temperature and rainfall changes from the Geophysical Fluid Dynamics Laboratory model there was a 32% increase in runoff, and with the Canadian Climate Centre Model, there was a 15% decrease in runoff. Under a climate scenario generated by the United Kingdom Meteorological Office model, runoff is estimated to increase by 5%. The use of incremental scenarios revealed the strong sensitivity of runoff to changes in rainfall as compared with changes in temperature.     

Vulnerability and adaptation of the larch forest in eastern Siberia to climate change

The most widely distributed coniferous forests in the world are the larch forests. In the Russian Federation they occupy 27.6 × 10⁶ ha. In Siberia, the larch species Larix russica generally grows west of the Yenissei River, and Larix gmelinii grows to the east. The morphological and physiological features of L. gmelinii make it possible for this species to grow in the far north of eastern Siberia, where climate conditions are more severe: The range of air temperature fluctuations in this region is more than 100°C, from 38°C down to 64°C below zero. One of the major adaptions to unfavorable soil conditions is provided by a specific feature of root formation in L. gmelinii, in which the apex central root dies off at the permafrost border and a root system develops in upper soil layers. The major larch vulnerability factors are natural and anthropogenic fires and damage caused by insects, which become more frequent with hot and dry weather. The consequences of projected global warming could be both positive and negative for larch forests. Permafrost melting may result in improved soil nutrition in the areas the larch forests occupy, yet the frequency of forest fires and damage by pathogens are likely to increase. Global warming is expected to cause forest die back and increased areas of steppe in the southern regions of eastern Siberia.     

Vulnerability of Sri Lanka tea production to global climate change

The tea industry is Sri Lanka's main net foreign exchange earner and source of income for the majority of laborers. Tea yield is greatly influenced by weather, and especially by droughts, which cause irreparable losses because irrigation is seldom used on tea plantations. At the other extreme, heavy rains erode top soil and wash away fertilizers and other chemicals. In the recently published Sri Lanka country report on climate change, it was reported that the island will experience extreme rainfall intensities and warmer temperatures as a result of climate change. The possibility of a 10% increase in the length of dry and wet seasons per year in the main plantation area was also indicated. Thus both drought damages and soil losses in tea production areas will increase in the years to come. An analysis of the results of field experiments with weather data shows that increases in temperature, soil moisture deficit, and saturation vapor pressure deficit in the low elevations will adversely affect growth and yield of tea. Reports have also shown that about 30 cm of soil has already been eroded from upland tea plantations. Under these circumstances, the tea industry in Sri Lanka is clearly vulnerable to predicted climate changes, and subsequently greater economic, social, and environmental problems. This paper discusses the various aspects of the adverse effects of climate change on Sri Lanka's tea industry.     

Vulnerability of bangladesh to climate change and sea level rise through tropical cyclones and storm surges

Bangladesh is frequently visited by natural disasters such as tropical cyclones, storm surges, floods, droughts, tornadoes, and “norwesters.” Of these, tropical cyclones originating in the Bay of Bengal and associated storm surges are the most disastrous. There are various reasons for the disastrous effects of cyclones and storm surges in Bangladesh. Superimposed on these disastrous effects, climate change and any consequent sea level rise are likely to add fuel to the fire. Arise in temperature is likely to change cyclone activity: cyclone intensity, if not cyclone frequency, may increase. As a result, storm surges may also increase substantially. Sea level rise, an increase in cyclone intensity, and consequent increases in storm surge heights will have disastrous effects on a deltaic country like Bangladesh, which is not much above the mean sea level. This paper examines the climatology of cyclones in the Bay of Bengal for the last 110 years and trends in cyclone frequency and intensity. The phenomenon of storm surges in the Bay of Bengal is examined along with the primary reasons for the severity of storm surges in Bangladesh. The paper discusses both qualitatively and quantitatively the impacts of rises in temperature on tropical cyclone intensity in Bangladesh. With the use of a mathematical model developed for the simulation of storm surges along the Bangladesh coast; various scenarios of storm surges are developed. Using lower and upper bounds of sea surface temperature rise of 2 and 4°C and of sea level rise of 0.3 and 1.0 m (according to the Intergovernmental Panel on Climate Change standard), the model simulates the maximum possible surges that are likely to occur under these conditions.     

Effects of interannual climate variability and climate change on rice yield in Java, Indonesia

About 60% of the nearly 40 x 106 t of rice produced in Indonesia are from the island of Java. However, the rice self-sufficiency that has been attained and maintained since 1984 could be threatened by changing climate, and has been affected by the climate variability effects of the El Nino/Southern Oscillation phenomenon. To aid policy makers and planners in formulating strategic policy options, the effects of recurring droughts and possible climate change on rice yields were studied using climate and crop models. Three models were used to simulate climate change: those of the Goddard Institute for Space Studies, Geophysical Fluid Dynamics Laboratory, and the United Kingdom Meteorological Office. Several climate scenarios were generated for Ngawi, in East Java, and Sukamandi, in West Java. These models indicate that doubling greenhouse gases would increase solar radiation by 1.2–2.1%, minimum and maximum temperatures by 7.6–16.8°C, and precipitation by 20.5–91.7%. The Goddard Institute for Space Studies transient climate change scenarios indicate that maximum and minimum temperatures would increase by 3.5 and 4.9%, respectively, in 2010, 6.9 and 9.8%, respectively, in 2030, and 11.1 and 15.7%, respectively, in 2050. The rainfall Agrotechnology Transfer crop model slightly under-predicts lowland rice yields of several experimental plots in three sites in Java and one site in Sumatra, but the results are almost equal to or a little higher than farm level yields. Nevertheless, the simulation outputs and experimental plots yields are closely related with a coefficient of determination value of 87%. Changes in climate in the decades of 2010, 2030, and 2050 could drastically reduce rice yield: the rice yield is estimated to decrease by about 1 % annually in East Java and less in West Java. Currently, the rice yields in dry     

Invertebrates increase the sensitivity of non-labile soil carbon to climate change

The fate of global soil carbon stores in response to predicted climate change is a ‘hotly’ debated topic. Considerable uncertainties remain as to the temperature sensitivity of non-labile soil organic matter (SOM) to decomposition. Currently, models assume that organic matter decomposition is solely controlled by the interaction between climatic conditions and soil mineral characteristics. Consequently, little attention has been paid to adaptive responses of soil decomposer organisms to climate change and their impacts on the turnover of long-standing terrestrial carbon reservoirs. Using a radiocarbon approach we found that warming increased soil invertebrate populations (Enchytraeid worms) leading to a greater turnover of older soil carbon pools. The implication of this finding is that until soil physiology and biology are meaningfully represented in ecosystem carbon models, predictions will underestimate soil carbon turnover.     

A new paradigm for assessing the role of agriculture in the climate system and in climate change

This paper discusses the diverse climate forcings that impact agricultural systems, and contrasts the current paradigm of using global models downscaled to agricultural areas (a top-down approach) with a new paradigm that first assesses the vulnerability of agricultural activities to the spectrum of environmental risk including climate (a bottom-up approach). To illustrate the wide spectrum of climate forcings, regional climate forcings are presented including land-use/land-cover change and the influence of aerosols on radiative and biogeochemical fluxes and cloud/precipitation processes, as well as how these effects can be teleconnected globally. Examples are presented of the vulnerability perspective, along with a small survey of the perceived drought impacts in a local area, in which a wide range of impacts for the same precipitation deficits are found. This example illustrates why agricultural assessments of risk to climate change and variability and of other environmental risks should start with a bottom-up perspective.     

Impacts of climate change on irrigated potato production in a humid climate

The impacts of climate change on the irrigation water requirements and yield of potatoes (Solanum tuberosum L.) grown in England have been assessed, by combining the downscaled outputs from an ensemble of general circulation models (GCM) with a potato crop growth model. The SUBSTOR-Potato model (embedded within the DSSAT program) was used to simulate the baseline and future irrigation needs (mm) and yield (t ha⁻¹) for selected emissions scenario (SRES A1FI and B1) for the 2050s, including CO₂ fertilisation effects. The simulated baseline yields were validated against independent experimental and field data using four reference sites. Probabilistic distribution functions and histograms were derived to assess GCM modelling uncertainty on future irrigation needs. Assuming crop husbandry factors are unchanged, farm yields would show only marginal increases (3-6%) due to climate change owing to limitations in nitrogen availability. In contrast, future potential yields, without restrictions in water or fertiliser, are expected to increase by 13-16%. Future average irrigation needs, assuming unconstrained water availability, are predicted to increase by 14-30%, depending on emissions scenario. The present ‘design’ capacity for irrigation infrastructure would fail to meet future peak irrigation needs in nearly 50% of years. Adaptation options for growers to cope with these impacts are discussed.     

Conservation policies and planning under climate change

Biodiversity conservation policies focus on securing the survival of species and habitats according to their current distribution. This basic premise may be inappropriate for halting biodiversity decline under the dynamic changes caused by climate change. This study explores a dynamic spatial conservation prioritization problem where climate change gradually changes the future habitat suitability of a site’ current species. This has implications for survival probability, as well as for species that potentially immigrate to the site. The problem is explored using a set of heuristics for both of two policy objectives focusing on (1) the protection on current (native) species, and (2) all species, including immigrating species. The trade-offs between the protection of native species versus all species is illustrated. The study shows that the development of prediction models of future species distributions as the basis of decision rules can be crucial for ensuring the effectiveness of conservation plans. Finally, it is discussed how more adaptive strategies, that allow for the redirection of resources from protected sites to privately-owned sites, may increase the effectiveness of the conservation networks. Climate change induced shifts in the suitability of habitats for species may increase the value of such adaptive strategies, the benefit decreasing with increasing migration probabilities and species distribution dynamics.     

Culture and climate change: Japanese cherry blossom festivals and stakeholders’ knowledge and attitudes about global climate change

Most global climate change models predict serious ecological and social problems. In Japan, biologists have found climate change is affecting species and ecosystems, including the earlier flowering time of cherry trees which are an important cultural symbol in Japan. Cherry blossom festivals are also important to local economies. This study explored the perceptions of Japanese residents regarding climate change impacts on culturally significant events such as flower timing of cherry trees. We conducted interviews of stakeholders of three cherry blossom festivals, including sixteen organizers of festivals and 26 managers of festival-dependent businesses, to understand their awareness, attitudes and behaviors toward global climate change and impacts on cherry blossom festivals. Most organizers of the festival in Kakunodate were concerned about global warming and its impact on cherry blossom times while organizers of festivals in Nakano and Komoro felt it was unimportant if flower timing affected the festival schedule. Most (92%) managers of festival-dependent businesses mentioned that global warming is occurring and affecting the flower timing of cherry trees, but there were diverse perceptions of global warming impacts on their business. Managers more dependent on income from cherry blossom festivals indicated greater concern for the effects of climate change.     

延河流域径流过程对气候变化及人类活动的响应

在全球气候变暖背景下,关注流域水文与气象要素的变化尤为必要.为了揭示气候变化及人类活动对延河流域径流的影响程度,本文运用Mann-Kendall方法和重标极差法,分析流域径流深、降水和气温等要素在1955-2012年间的变化;利用Pettitt突变检验,识别出径流的突变年份,并采用水文敏感性分析方法,定量区分气象因素和人类活动对延河流域径流变化的贡献.结果表明:1955-2012年,延河流域降水减少89.4 mm,气温升高2.15℃,径流深减少17.3 mm,呈现暖干化趋势.径流突变发生在1996年,与1955-1995年相比,1996-2012年的年平均径流深减少11.7 mm;其中人类活动对径流减少的贡献率为56％.研究阐明延河流域气候有暖干化的趋势,且人类活动作用在径流减少中所占比重较大,并对该区水资源合理利用与管理具有较好的指导意义.     

The impacts of potential climate change and climate variability on simulated maize production in China

This study assessed the impacts of potential climate change on maize yields in China, using the CERES-Maize model under rainfed and irrigated conditions, based on 35 maize modeling sites in eastern China that characterize the main maize regions. The Chinese Weather Generator was developed to generate a long time series of daily climate data as baseline climate for 51 sites in China. Climate change scenarios were created from three equilibrium general circulation models: the Geophysical Fluid Dynamics Laboratory model, the high-resolution United Kingdom Meteorological Office model, and the Max Planck Institute model. At most sites, simulated yields of both rainfed and irrigated maize decreased under climate change scenarios, primarily because of increases in temperature, which shorten maize growth duration, particularly the grain-filling period. Decreases of simulated yields varied across the general circulation model scenarios. Simulated yields increased at only a few northern sites, probably because maize growth is currently temperature-limited at these relatively high latitudes. To analyze the possible impacts of climate variability on maize yield, we specified incremental changes to variabilities of temperature and precipitation and applied these changes to the general circulation model scenarios to create sensitivity scenarios. Arbitrary climate variability sensitivity tests were conducted at three sites in the North China Plain to test maize model responses to a range of changes (0%, +10%, and +20%) inthe monthly standard deviations of temperature and monthly variation coefficients of precipitation. The results from the three sites showed that incremental climate variability caused simulated yield decreases, and the decreases in rainfed yield were greater than those of irrigated yield.     

Using behavioral landscape ecology to predict species’ responses to land-use and climate change

Climate change and habitat destruction are widely recognized as major threats to species’ survival. As a result of these anthropogenic impacts, species are often forced into novel landscapes where their persistence is difficult to predict. Knowledge of how individuals move or disperse through the landscape, choose habitat in which to settle, and produce offspring which survive to repeat the process can greatly improve our ability to predict species’ persistence. The field of behavioral landscape ecology uses a strong theoretical base to explore, often experimentally, how the behavior of a particular species is affected by heterogeneous and rapidly changing landscapes and can offer valuable insight for managing species in the face of human-induced environmental changes. When interpreted by modelers, results of landscape-level behavioral experiments can be quantified for use in predictive models. To this end, we summarize the methods and results of research using direct experimental manipulation techniques broken into the following categories: translocations, playback experiments, food resource manipulations, manipulations of reproductive success, direct manipulations of the landscape, and manipulations of predation risk. We review and place in a theoretical framework the results from this emerging body of research regarding how organisms move in and respond to different types of landscapes, both natural and human-altered. We go onto highlight the potential of each experimental method to quantify different processes, which may be useful when interpreted by modelers attempting to parameterize predictive models. Finally, we suggest future directions for experimental research that will allow for greater integration of behavioral landscape ecology and predictive modeling.     

The interdependence of ammonia volatilization and denitrification as nitrogen loss processes in flooded rice fields in the Philippines

Summary The relative importance of ammonia volatilization and denitrification as loss processes following the application of urea to flooded rice by the traditional method was assessed at four sites with different characteristics in the Philippines. The effect of reducing ammonia loss on denitrification and total N loss was also studied. The total N loss was determined by a ¹⁵N-balance method and ammonia volatilization was assessed by a bulk aerodynamic method following the application of urea to small plots (4.8×5.2 m). As run-off was prevented and leaching losses were negligible, the denitrification loss was assessed as the difference between total N loss and ammonia loss. When urea was broadcast into the floodwater at transplanting, the ammonia loss varied from 10% to 56% of the applied N. Loss was smallest at Aguilar where wind speeds were low and the greatest at Mabitac where floodwater pH values and temperatures were high and the winds were strong. The ammonia loss was reduced at all sites by incorporating the urea into the soil by harrowing. However, the reduction achieved varied markedly between sites, with the largest reduction (from 56% to 7% loss of the applied N) being observed at Mabitac. The total N lost from the basal application into the floodwater ranged from 59% to 71% of the applied N. Incorporating the urea by harrowing reduced the total N loss at two sites, increased the total N loss at the third site, and had no effect at the fourth site. The denitrification losses ranged widely (from 3% to 50% of the applied N) when urea was broadcast into the floodwater at the four sites. The denitrification loss was low when the ammonia loss was high (Mabitac) and high when the ammonia loss was low (Aguilar). Reducing ammonia losses by incorporating the urea into the flooded soil resulted in increased denitrification losses at three of the sites and appeared to have no effect on denitrification at the fourth site. The results show that reducing the ammonia loss by incorporating urea into the soil does not necessarily result in reduced total N loss, and suggest that the efficiency of fertilizer N will be improved only when both N-loss processes are controlled simultaneously.     

Implications of climate change for tillage practice in Australia

The world is experiencing climate change that in no way can be considered normal, and the challenge that this brings to agriculture is twofold. The first challenge relates to the continuing need to reduce greenhouse gas emissions that generate the changes to climate. Australia's National Greenhouse Gas Inventory estimates that agriculture produces about one-quarter of Australia's total greenhouse gas emissions (including land clearing). The main gases emitted are carbon dioxide, methane, and nitrous oxide. These gases are derived from high-value components within the agricultural production base, so reducing emissions of greenhouse gases from agriculture has the potential to provide production and financial benefits, as well as greenhouse gas reduction. Methane essentially derives from enteric fermentation in ruminants. Nitrous oxide and carbon dioxide, on the other hand, are strongly influenced, and perhaps even determined by a range of variable soil-based parameters, of which the main ones are moisture, aerobiosis, temperature, amount and form of carbon, organic and inorganic nitrogen, pH, and cation exchange capacity. Tillage has the potential to influence most of these parameters, and hence may be one of the most effective mechanisms to influence rates of emissions of greenhouse gases from Australian agriculture. There have been substantial changes in tillage practice in Australia over the past few decades – with moves away from aggressive tillage techniques to a fewer number of passes using conservative practices. The implications of these changes in tillage for reducing emissions of greenhouse gases from Australian agriculture are discussed.

The second challenge of climate change for Australian agriculture relates to the impacts of climate change on production, and the capacity of agriculture to adapt where it is most vulnerable. Already agriculture is exposed to climate change, and this exposure will be accentuated over the coming decades. The most recent projections for Australia provided by the CSIRO through the Australian Climate Change Science Programme, indicate that southern Australia can expect a trend to drying due to increased temperatures, reduced rainfalls, and increased evaporative potentials. Extremes in weather events are likely also to become more common. We anticipate that climate change will become an additional driver for continued change in tillage practice across Australia, as land managers respond to the impacts of climate change on their production base, and governments undertake a range of activities to address both emissions reduction and the impacts of climate change in agriculture and land management.     

Soil solution and extractable soil nitrogen response to climate change in two boreal forest ecosystems

Several studies show that increases in soil temperature result in higher N mineralization rates in soils. It is, however, unclear if additional N is taken up by the vegetation or accumulates in the soil. To address this question two small, forested catchments in southern Norway were experimentally manipulated by increasing air temperature (+3°C in summer to +5°C in winter) and CO₂ concentrations (+200 ppmv) in one catchment (CO₂T-T) and soil temperature (+3°C in summer to +5°C in winter) using heating cables in a second catchment (T-T). During the first treatment year, the climate treatments caused significant increases in soil extractable NH₄ under Vaccinium in CO₂T-T. In the second treatment year extractable NH₄ in CO₂T-T and NO₃ in T-T significantly increased. Soil solution NH₄ concentrations did not follow patterns in extractable NH₄ but changes in soil NO₃ pools were reflected by changes in dissolved NO₃. The anomalous behavior of soil solution NH₄ compared to NO₃ was most likely due to the higher NH₄ adsorption capacity of the soil. The data from this study showed that after 2 years of treatment soil inorganic N pools increased indicating that increases in mineralization, as observed in previous studies, exceeded plant demand and leaching losses.     

Assessing sensitivity to climate change and drought variability of a sand dune endemic lizard

Bioclimatic models aimed assessing a species’ sensitivity to climate change incorporate mean shifts in climate variables; however the more acute threat to the persistence of species may result from increased frequency of extreme climatic events, including increased duration and severity of droughts. Here we assess climate-change sensitivity using niche modeling that unlike bioclimatic modeling incorporates both climate variables as well as other habitat features that constrain a species’ distribution. We analyzed the effects of potential increases in drought frequency for an endangered, sand dune-restricted lizard, a species restricted to a narrowly occurring substrate and so unable to move up-slope or pole-ward to track climate shifts. Our niche modeling results indicated only minor losses to the area of suitable niche space at lower levels of modeled climate change; at the most severe climate shifts we tested the area of suitable niche space reduced by slightly more than 50%. However, extrapolating the potential impacts of reduced rainfall on drought periodicity and intensity showed a more immediate and acute impact on the lizard’s populations. Drought duration projections coupled with landscape fragmentation resulted in rapid losses of suitable niche space, beginning in the more arid portion of the lizard’s range and extending into more moderate climate areas. Although there is greater uncertainty associated with the impacts of climate change on drought periodicity than with shifts in mean conditions, our results show a greater potential for droughts to negatively impact species’ resilience to such changes.     

Molecular degradation rate of rice and corn starches during acid-methanol treatment and its relation to the molecular structure of starch

The degradation rates of rice and corn starches with different contents of amylose treated in methanol containing 0.36% HCl at 25 degrees C for 1-15 days were evaluated by monitoring the weight average degree of polymerization of starch. A two-stage degradation pattern during acid-methanol treatment was found for the starches studied, which were the slow (first) and the rapid (second) degradation stages. Waxy starches showed a shorter time period of the first stage than that of nonwaxy starch. Rice starch showed a shorter time period of the first stage and a higher degradation rate of the second stage than the counterpart corn starch with similar amylose content. Despite the botanic source and amylose content of starch, the degradation rate of starch in the second stage significantly (p < 0.05) correlated to the S/L ratio (r = -0.886) and polydispersity (r = 0.859) of amylopectin branch chains of native starch.     

Assisted colonization: Integrating conservation strategies in the face of climate change

Global climate change poses an immense challenge for conservation biologists seeking to mitigate impacts to species and ecosystems. Species persistence will depend on geographic range shifts or adaptation in response to warming patterns as novel climates and community assemblages arise. Assisted colonization has been proposed as a method for addressing these challenges. This technique, which consists of transporting species to a new range that is predicted to be favorable for persistence under future climate scenarios, has become the subject of controversy and discussion in the conservation community due to its highly manipulative nature, questions about widespread feasibility, and uncertainty associated with the likelihood of translocated species becoming invasive. We reviewed the discussion and criticism associated with assisted colonization and sought to identify other conservation techniques that also display potential to promote the colonization and adaptation of species in response to climate change. We propose an integrated conservation strategy that includes management for habitat connectivity, conservation genetics, and when necessary, assisted colonization of species that are still unable to shift their ranges even given implementation of the above standard conservation approaches. We argue that this integrated approach will facilitate persistence for a larger proportion of species than is possible by solely using assisted colonization. Furthermore, a multi-faceted approach will likely reduce the uncertainty of conservation outcomes and will become increasingly necessary for conservation of biodiversity in a changing climate.     

Implications of climate change scenarios for soil erosion potential in the USA

Atmospheric general circulation models (GCMs) project that increasing atmospheric concentrations of CO2 and other greenhouse gases May, result in global changes in temperature and precipitation over the next 40-100 years. Equilibrium climate scenarios from four GCMs run under doubled CO2 conditions were examined for their effect on the climatic potential for sheet and rill erosion in the conterminous USA. Changes in the mean annual rainfall factor (R) in the Universal Soil Loss Equation (USLE) were calculated for each cropland, pastureland and rangeland sample point in the 1987 National Resources Inventory. Projected annual precipitation changes were assumed to be from differences in either storm frequency or storm intensity. With all other USLE factors held constant these changes in R translated to changes in the sheet and rill erosion national average of +2 to +16 per cent in croplands, -2 to +10 per cent in pasturelands and -5 to +22 per cent in rangelands under the eight scenarios. Land with erosion rates above the soil loss tolerance (T) level and land classified as highly erodible (eredibility index >8) also increased slightly. the results varied from model to model, region to region and depended on the assumption of frequency versus intensity changes. These results show the range of sensitivity of soil erosion potential by water under projected climate change scenarios. However, actual changes in soil erosion could be mitigated by alterations in cropping patterns and other management practices, or possibly by increased crop growth and residue production under higher atmospheric CO2 concentrations.