Material Flow and Spatial Data Analysis of the Petroleum Use to Carbon Dioxide (CO2) Emissions in Northeast China

This study investigated the petroleum consumption and petroleum‐related CO₂ emissions (PCOEs) in Northeast China at city level using material flow analysis (MFA) and spatial data analysis (SDA). The petroleum flows for the year 2014 were plotted, and then the spatial patterns, weighted mean centers (WMCs), and spatial autocorrelations of petroleum consumption and PCOEs were calculated, respectively. It was found that Northeast China is a petroleum exploitation‐processing‐export region in China; the total input of petroleum flows comprised two parts—exploitation (about 60%) and import (about 40%). About one third of the total product oil supply flowed into other provinces. In the consumption process, the product oil was dominated by two sectors: the industry sector (45.5%) and the transportation sector (31%). The rate of PCOEs was 36.69 million tonnes in the waste discharge process. Meanwhile, the WMCs of the petroleum consumption and the PCOEs were located in the south of Northeast China. The location of the petroleum pipelines was the factor shown to determine the spatial patterns of petroleum consumption and PCOEs and the hotspots were distributed along the petroleum pipeline, especially in the Circum‐Bohai Sea regions. Economic development in these regions shows a positive dependence on petroleum consumption and generates larger PCOEs. The findings obtained in this study could provide important decision‐making support to low‐carbon development in Northeast China.     

Production and Resource Use Efficiencies in N- and P-Limited Tropical Forests: A Comparison of Responses to Long-term Fertilization

At two sites at the extreme ends of a soil development chronosequence in Hawaii, we investigated whether forest responses to fertilization on young soils were similar to those on highly weathered soils and whether the initial responses were maintained after 6–11 years of fertilization. Aboveground net primary production (ANPP) was increased by nitrogen (N) application at the 300-year-old site and phosphorus (P) application at the 4.1-million-year-old site, thus confirming earlier results and their designations as N- and P-limited forests. Along with ANPP, application of the limiting element consistently increased leaf area index (LAI), radiation conversion efficiency (RCE), and foliar and litter nutrient concentrations. Fertilization did not consistently alter N or P retranslocation from senescent leaves at either site, but a comparison with other sites on the chronosequence and with a common-garden study suggests that there is a genetic basis for low foliar and litter nutrients and higher retranslocation at infertile sites vs more fertile sites. N limitation appears to be expressed as limitation to carbon gain, with long leaf lifespans and high leaf mass per area. P limitation results in high P-use efficiency and disproportionally large increases in P uptake after fertilization; a comparison with other studies indicates large investments in acquiring and storing P. Although the general responses of ANPP, LAI, and RCE were similar for the two sites, other aspects of nutrient use differ in relation to the physiological and biogeochemical roles of the two elements. Received 2 June 2000; Accepted 4 April 2001.     

The interaction between CO2 and plant nutrition: comments on a paper by Coleman,McConnaughay and Bazzaz

Effects of CO₂ on plants are often confounded with effects of nutrition. Coleman et al. (1993) showed that nitrogen concentrations in plants grown under different CO₂ levels did not differ if plants of equal sizes were compared but varied at equal times and equal sizes for different levels of nitrogen additions. I will suggest why this must occur under the conditions of the experiment. I will also suggest why nitrogen productivity should be used to interpret experimental results rather than the dubious nitrogen use efficiency.     

Changes in Stomatal Conductance,Transpiration and Water Use Efficiency of Ten Species Experienced in High CO2 Concentrations in Biosphere 2

The stomotal conductance, transpiration and water use efficiency (WUE) were measured using a LI-6400 portable photosynthesis system for 5 tropical rain forest species and 5 desert species in Biosphere 2, USA. All the species have experienced in very high CO2 ( > 2 200 μmol• mol- 1 ) for more than 4.5 years. The results showed that the stomatal conductance and transpiration of rain forest species decreased from ( 127.4 ± 65.6) and (2.04 ± 0.61 ) mmol• m- 2•s- 1 to (61.3 + 30.5) and ( 1.54 ± 0.65 ) mmol• m-2• s -1 respectively, while WUE increased from (2.90 ± 0.55) to (8.45 ± 2.71) μmol CO2 •mmo1-1 H2O, with CO2 increasing from 350 – 400 to 700 – 820 μmol• mol-l. For the desert species, stomatal conductance and transpiration decreased from respectively (142.8±94.6) and (2.09±0.71) mmol•m-2•s-1 to (57.7±35.8) and (1.36±0.52) mmolm-2•s-l, but WUE increased from (4.69 ± 1.39) to (9.68 ± 1.61) μmol CO2•mmo1-1 H2O, with the CO2 increase from 320 - 400 to 820 – 850 μtmol• mol- 1. The stomatal conductance, transpiration and WUE were less influenced by light intensity under high CO2 than low CO2 concentrations. Most rain forest species reached their light saturation points at light intensity of 500 μmol• m-2•s-1, while desert species at 1 000 μmol•m-2•s-1. Among different species, the desert C3 tree, Nicotiana glauca Grah., had the highest decrease in stomatal conductance and transpiration and the highest increase in WUE, by 78%, 69% and 310% respectively. The enhancement of increasing CO2 to the stomatal, transpiration and WUE of species with different photosynthesis pathway and life forms in Biosphere 2 could be concluded as: C3 species > C4 species, and desert C3 species > rain forest C3 species.     

CO2浓度升高和干旱对春小麦生长和水分利用的生态效应

利用开顶式气室对春小麦进行了一个生长季的CO2倍增盆栽实验,土壤水分控制为3个水平(分别为田间持水量(FWC)的80%、60%、40%).结果显示,CO2倍增显著提高小麦的光合速率.但在相同的CO2测定浓度下, 生长在加倍CO2浓度下的小麦的光合速率比当前CO2浓度下小麦低22%.高CO2浓度显著促进小麦生长,相对增加幅度在适宜水分下最大,为14.8%.80%FWC水分条件下高CO2使植株的干重/高度比增加15.7%.高CO2条件下,小麦的蒸腾速率降低、累积耗水量减少、水分利用效率(WUE)提高,WUE的提高幅度在适宜水分下最大,为30%.干旱(40%FWC)使小麦地上干重和WUE在当前CO2条件下分别降低72%和19%,加倍CO2条件下降低幅度较大,分别为76%和23%.根据以上结果得出结论: (1) 高CO2条件下, 小麦的光合速率、地上生物量和水分利用效率提高;(2) 植物长期生长于高CO2浓度导致光合能力降低;(3) 高CO2对植物侧向生长的促进作用大于垂直生长,即高CO2下植株将相对粗壮;(4) 高CO2对植物的生态效应依赖于土壤水分,在适宜水分下相对较大;(5) 在未来高CO2条件下,干旱引起的减产和水分利用效率减低幅度将会更大.     

Plasticity in Resource Allocation and Nitrogen-use Efficiency in Riparian Vegetation: Implications for Nitrogen Retention

In this work, we summarize our current understanding of the function of riparian zones and describe an investigation of changes in the production per unit nitrogen (N) taken up, or nitrogen-use efficiency (NUE) and resource allocation of a riparian shrub in response to changes in N availability. Empirical work included measuring leaf %N and root-to-shoot ratios (R:S) of individual riparian shrubs (Baccharis salicifolia, or seepwillow) growing at a range of N availabilities in the field and growing in fertilized and unfertilized plots in a field fertilization experiment. In both observational and experimental work, N availability was related positively to %N of plant tissues and negatively to R:S. We used a simulation model to investigate feedbacks between seepwillow responses to and effects on N availability. In the model, plasticity in resource allocation and NUE in response to changes in N led to lower productivity at low N supply and higher productivity and lower retention at high N supply than was observed in plants constrained to a constant %N and R:S. Furthermore, uptake became relatively more important as a retention mechanism when plants responded to high N supply. These feedbacks could have significant effects on N retention by riparian zones in watersheds receiving large fertilizer inputs of N or on ecosystems exposed to high rates of atmospheric N deposition.     

Indigenous Land Use in the Ecuadorian Amazon: A Cross-cultural and Multilevel Analysis

Among the remaining tropical forests of lowland Latin America, many are inhabited by indigenous peoples, and the sustainability of their land uses is a point of heated debate in the conservation community. Numerous small-scale studies have documented changes in indigenous land use in individual communities in the context of expanding frontier settlements and markets, but few studies have included larger populations or multiple ethnic groups. In this paper we use data from a regional-scale survey of five indigenous populations in the Northern Ecuadorian Amazon to describe their agricultural land use practices and investigate the factors that affect those practices. We find the areas cultivated by indigenous households to be small compared to those of nearby mestizo colonists, but a large proportion of indigenous cultivated area is in commercial land uses. We also construct multilevel statistical models to investigate the household and community-level factors that affect indigenous land use. The results reveal significant influences on cultivated area from contextual factors such as access to markets, oil company activities, and the land tenure regime, as well as from household characteristics such as demographic composition, participation in alternative livelihood activities, and human, social and physical capitals. Overall the results are most consistent with market integration as an underlying driver of land use change in indigenous territories of the study area.

Long-Term Habitat Use by Mountain Gorillas (Gorilla gorilla beringei). 2. Reuse of Foraging Areas in Relation to Resource Abundance, Quality, and Depletion

Resource depression caused by current feeding and the rate of resource renewal should influence foragers' decisions about when to revisit foraging areas. Adjustment of foraging paths and revisit rates should be particularly important when resources renew slowly. Foragers can also benefit by returning more often to highly profitable than to less profitable foraging areas. Many highly frugivorous primates seem to time revisits to fruit sources so as to harvest fruit efficiently and, also, use efficient search paths. Fewer data on non-frugivores exist. Mountain gorillas are folivores that eat mostly perennially available, continuously growing herbs and vines. Vegetation regenerates slowly from the effects of gorilla trampling, though trampling can also facilitate food species productivity, at least in the short term. Adjustment of intervals between visits to foraging areas to the extent of previous use and to resource renewal rates should increase gorilla foraging efficiency. Long-term data on habitat use by 6 mountain gorilla social units show that revisit intervals vary in association with variation in the extent of previous use and in plant productivity. However, they also revisit areas more often, the higher the biomass and nutritional quality of food there. These data are generally consistent with the hypothesis that the gorillas crop resources on a sustained-yield basis, though more precise data on areal revisits and complementary long-term data on vegetation composition would be needed to test the hypothesis.     

Ecosystem Nutrient Use Efficiency, Productivity, and Nutrient Accrual in Model Tropical Communities

Ecosystem nutrient use efficiency–the ratio of net primary productivity to soil nutrient supply–is an integrative measure of ecosystem functioning. High productivity and nutrient retention in natural systems are frequently attributed to high species diversity, even though some single-species systems can be highly productive and effective at resource capture. We investigated the effects of both individual species and life-form diversity on ecosystem nutrient use efficiency using model tropical ecosystems comprised of monocultures of three tree species and polycultures in which each of the tree species was coplanted with species of two additional life forms. Tree species significantly influenced nutrient use efficiency by whole ecosystems in monocultures; however, in polycultures, the additional life forms interacted with the influence exerted by the dominant tree. Furthermore, the presence of the additional life forms significantly increased nutrient uptake and uptake efficiency, but in only two of the three systems and 2 of the 4 years of the study period. These results indicate that the effect of life-form diversity on ecosystem functioning is not constant and that there may be temporal shifts in the influence exerted by different components of the community. Furthermore, although species (and life forms) exerted considerable influence on ecosystem nutrient use efficiency, this efficiency was most closely related to soil nutrient availability. These findings demonstrate that ecosystem nutrient use efficiency is an outcome not only of the characteristics of the species or life forms that comprise the system but also of factors that affect soil nutrient supply. The results argue against the simple upward scaling of nutrient use efficiency from leaves and plants to ecosystems. Received 29 March 2000; accepted 27 April 2001.     

Towards a Circular Economy in Australian Agri‐food Industry: An Application of Input‐Output Oriented Approaches for Analyzing Resource Efficiency and Competitiveness Potential

The food industry in Australia (agriculture and manufacturing) plays a fundamental role in contributing to socioeconomic sectors nationally. However, alongside the benefits, the industry also produces environmental burdens associated with the production of food. Sectorally, agriculture is the largest consumer of water. Additionally, land degradation, greenhouse gas emissions, energy consumption, and waste generation are considered the main environmental impacts caused by the industry. The research project aims to evaluate the eco‐efficiency performance of various subsectors in the Australian agri‐food systems through the use of input‐output–oriented approaches of data envelopment analysis and material flow analysis. This helps in establishing environmental and economic indicators for the industry. The results have shown inefficiencies during the life cycle of food production in Australia. Following the principles of industrial ecology, the study recommends the implementation of sustainable processes to increase efficiency, diminish undesirable outputs, and decrease the use of nonrenewable inputs within the production cycle. Broadly, the research outcomes are useful to inform decision makers about the advantages of moving from a traditional linear system to a circular production system, where a sustainable and efficient circular economy could be created in the Australian food industry.     

Response of wheat growth,grain yield and water use to elevated CO2 under a Free‐Air CO2 Enrichment (FACE) experiment and modelling in a semi‐arid environment

The response of wheat crops to elevated CO₂ (eCO₂) was measured and modelled with the Australian Grains Free‐Air CO₂ Enrichment experiment, located at Horsham, Australia. Treatments included CO₂ by water, N and temperature. The location represents a semi‐arid environment with a seasonal VPD of around 0.5 kPa. Over 3 years, the observed mean biomass at anthesis and grain yield ranged from 4200 to 10 200 kg ha^?1 and 1600 to 3900 kg ha^?1, respectively, over various sowing times and irrigation regimes. The mean observed response to daytime eCO₂ (from 365 to 550 μmol mol^?1 CO₂) was relatively consistent for biomass at stem elongation and at anthesis and LAI at anthesis and grain yield with 21%, 23%, 21% and 26%, respectively. Seasonal water use was decreased from 320 to 301 mm (P = 0.10) by eCO₂, increasing water use efficiency for biomass and yield, 36% and 31%, respectively. The performance of six models (APSIM‐Wheat, APSIM‐Nwheat, CAT‐Wheat, CROPSYST, OLEARY‐CONNOR and SALUS) in simulating crop responses to eCO₂ was similar and within or close to the experimental error for accumulated biomass, yield and water use response, despite some variations in early growth and LAI. The primary mechanism of biomass accumulation via radiation use efficiency (RUE) or transpiration efficiency (TE) was not critical to define the overall response to eCO₂. However, under irrigation, the effect of late sowing on response to eCO₂ to biomass accumulation at DC65 was substantial in the observed data (~40%), but the simulated response was smaller, ranging from 17% to 28%. Simulated response from all six models under no water or nitrogen stress showed similar response to eCO₂ under irrigation, but the differences compared to the dryland treatment were small. Further experimental work on the interactive effects of eCO₂, water and temperature is required to resolve these model discrepancies.     

The Photosynthetic Role of Ears in C3 Cereals: Metabolism,Water Use Efficiency and Contribution to Grain Yield

This review concerns ear photosynthesis and its contribution to grain filling in C₃ cereals. Ear photosynthesis is quantitatively important to grain filling, particularly in dry areas where source (i.e., assimilate) limitations can occur. Compared to the flag leaf, ear photosynthesis exhibits higher water stress tolerance. Several factors could be involved in the ear's “drought tolerance.” First, although degree of C₄ metabolism in ear parts has been reported, current evidence supports only typical C₃ metabolism. Second, recycling of respired CO₂ (i.e., refixation) could have considerable impact on final crop yield by preventing loss of CO₂. Because refixation of CO₂ is independent of atmospheric conditions, water use efficiency (measured as total ear photosynthesis divided by transpiration) could be higher in the ear than in the flag leaf. Moreover, ear parts (in particular awns) show higher relative water content and better osmotic adjustment under water stress compared to the flag leaf. This capacity, in addition to persistence of photosynthetic components under drought (delayed senescence), might help the ear to continue to fix CO₂ late in the grain filling period.     

水稻微核心种质氮素利用率相关性状的鉴定评价及其相关分析

以中国水稻微核心种质为试验材料,在低氮水平下进行了水稻氮素利用率相关性状的鏊定评价,分析了产量和氮素利用率相关性状的相关关系.结果表明,秸秆舍氮率和单株秸秆含氮量变幅分别为0.56%～1.85%和0.04～0.61 g,子粒舍氮率和单株子粒舍氮量变幅分别为1.28%～3.23%和0.02～1.04 g,植株舍氮量变幅为0.10～1.30 g,氮素子粒产量利用率和氮素生物产量利用率变幅分别为3.85～57.52 s/g和17.56～104.02 g/g,氮素收获指数变幅为7.05%～88.58%.氮素利用率相关性状在品种闻存在较大的差异.秸秆合氮率与舍氮量、子粒含氮率与含氮量和植株含氮量在粳稻和籼稻亚种间没有显著差异;氮素生物产量利用率籼稻略大于粳稻,但差异不显著;氮素子粒产量利用率与氮素收获指数在粳稻和籼稻亚种间存在较明显的差异.氮素子粒产量利用率、氮素收获指数与结实率、单株子粒重和单株有效穗数均呈板显著正相关;认为在低氮水平下,结实率、单株子粒重和单株有效穗数可以作为耐低氮与氮高效水稻种质的筛选指标.     

Responses to Doubled CO2 in Medicago sativa: Studies on Ecophysiology and Simulation Modelling

A world-wide spread forage grass, Medicago sativa, was grown in two open-top chambers maintained at either normal (350 μmol · mol-1) or doubled (700 μmol · mol-1) CO2 concentration, from seedling to maturity. During the whole growth season, ecophysiological measurements and observations were conducted over different phenological stages and the main results were as follows: (1) With similar environmental factors, in terms of RH (relative humidity), irradiance, and watering, a slight shift in temperature (about 0.77℃, averaged over the whole growth season) within the chamber maintained at doubled CO2 did not affect instantaneous physiological processes at leaf level, but had some impacts on the effect of doubled CO2 over a long period. (2) Over the whole growth season, physiological variables showed differences between two chambers. The net photosynthesis of plant grown under higher CO2 increased by 18.7 %, while stomatal conductance fell slightly as compared with that of the control. So was the water use efficiency which was also 30.1% higher than the control. Based on the above results from field studies, we concluded that photosynthetically active radiation (PAR) and RH were the main factors affecting photosynthesis and stomatal behavior. Then we combined a widely accepted model of C3 leaf photosynthesis with an empirical model of stomatal conductance and made some modifications according to our experiments. This model was parameterized using field data sets of net CO2 assimilation, stomatal conductance, intercellular CO2 concentration of plants grown at both doubled and control CO2 levels. Variances of main parameters between two treatments reflected some biochemical changes in leaf cell. The maximum efficiency of light energy conversion (α) increased by 22 % and light-saturated rate of electron transport (Jmax) rose by 15 %. The maximum stomatal conductance was slightly reduced by 8 %. The increases in parameters (α and Jmax) indicate accelerated biochemical processes in leaf cell, which means that the photosynthetic capacity of M. sativa may increase at elevated CO2. These results agree well with biochemical measurements at cell level.     

Socioeconomic Metabolism and Colonization of Natural Processes in SangSaeng Village: Material and Energy Flows, Land Use, and Cultural Change in Northeast Thailand

Conceptualizing environmental problems as sustainability problems contributing to local and global environmental change requires an understanding of how societies cope with their natural environment. Indicators for society–nature interactions are fairly well developed for national-level analyses. This study adapts some of these indicators to the local level and relates them to a qualitative assessment of economic and cultural change in a single community. Indicators are derived from material and energy flow accounting methods and address two major objectives: Firstly, to identify mutual influences between the global and the local level. Secondly, to assess future potentials of environmental pressures and impacts that can be expected to occur as such communities follow a path of further modernization. This study of a small rice-farming community in Northeast Thailand deals with physical as well as sociocultural aspects in order to produce a broad picture of society–nature relations. The indicators developed portray a society in the midst of transition and rapid modernization. This becomes apparent when comparing the results to those of similar studies in traditional and industrial societies. What we see is a community struggling to adapt to global influences, while at the same time maintaining subsistence with traditional coping mechanisms.     

Gas exchange and photosynthetic water use efficiency in response to light, CO2 concentration and temperature in Vicia faba

Light and temperature-response curves and their resulting coefficients, obtained within ecophysiological characterization of gas exchanges at the leaf level, may represent useful criteria for breeding and cultivar selection and required tools for simulation models aimed at the prediction of potential plant behaviour in response to environmental conditions.

Leaf-scale gas exchanges, by means of an IRGA open-flow system, were measured in response to light intensity (8 levels from 0 up to 2000 μmol m⁻² s⁻¹), CO₂ concentrations (ambient—350 μmol mol⁻¹ and short-term enriched—700 μmol mol⁻¹) and air temperature (from 7 up to 35 °C) on three Vicia faba L. genotypes, each representing one of the three cultivated groups: major, equina and minor. The net assimilation rate response to light intensity was well described by an exponential rise to max function. The short-term CO₂ enrichment markedly increased the values of light response curve parameters such as maximum photosynthetic rate (+80%), light saturation point (+40%) and quantum yield (+30%), while less homogenous behaviour was reported for dark respiration and light compensation point. For each light intensity level, the major and minor genotypes studied showed assimilation rates at least a 30% higher than equina.

The positive effects of short-term CO₂ enrichment on photosynthetic water use efficiency (WUE) indicate a relevant advantage in doubling CO₂ concentration. In the major and minor genotypes studied, similar assimilation rates, but different WUE were observed.

The optimum leaf temperature for assimilation process, calculated through a polynomial function, was 26–27 °C and no relevant limitations were observed in the range between 21 and 32 °C.

Analysis at the single leaf level provided both rapid information on the variations in gas exchange in response to environmental factors and selection criteria for the screening of genotypes.     

Photosynthetic Traits in Wheat Grown under Decreased and Increased CO2 Concentration, and after Transfer to Natural CO2 concentration

Wheat plants were grown from sowing to day 18 in 26-dm³ chambers at three different CO₂ concentrations: 150 (-CO₂), 350 (C, control), 800 (+CO₂) mol mol^-1. Afterwards, plants of the three variants were grown at the same natural CO₂ concentration. Plant characteristics were measured just before the transfer (0 days after CO₂ treatment, DAT), and at 5 – 8 DAT on the 1^st leaf, and at 12 – 22 DAT on the 4^th leaf. Decreased or increased CO₂ concentrations caused acclimations which persisted after transplantation to natural CO₂ concentration. At 5 – 8 DAT, stomatal density, stomatal conductance (g_s), CO₂ saturated net photosynthetic rate (P_Nsat0), radiation saturated net photosynthetic rate (P_Nsat1), and carboxylation efficiency () were higher in -CO₂ plants and lower in +CO₂ plants than in C plants. As compared with C plants, the photochemical efficiency () was lower in -CO₂ and higher in -CO₂ plants, however, chlorophyll (Chl) a, Chl b, Chl a–b and carotenoid contents were lower in both -CO₂ and +CO₂ plants. On the 4^th leaf, which emerged on plant after finishing CO₂ treatments, at 12 – 22 DAT, no differences in stomatal density and g, between treatments were observed. In -CO₂ plants, pigment content and P_Nsat0 were higher, was lower, and P_Nsat1 and were not different from C plants. In contrast, in +CO₂ plants, pigment content, P_Nsat1 and were lower, and P_Nsat0 and were unchanged. Leaf area, dry mass, and tiller development increased in +CO₂ plants and decreased in -CO₂ plants. In the interval between 8 and 22 DAT, lower net assimilation rate in +CO₂ than in -CO₂ plants was observed.     

Adaptation to high CO2 concentration in an optimal environment: radiation capture, canopy quantum yield and carbon use efficiency

The effect of elevated [CO₂] on wheat (Triticum aestivum L. Veery 10) productivity was examined by analysing radiation capture, canopy quantum yield, canopy carbon use efficiency, harvest index and daily C gain. Canopies were grown at either 330 or 1200 μ mol mol^–1[CO₂] in controlled environments, where root and shoot C fluxes were monitored continuously from emergence to harvest. A rapidly circulating hydroponic solution supplied nutrients, water and root zone oxygen. At harvest, dry mass predicted from gas exchange data was 102·8 ± 4·7% of the observed dry mass in six trials. Neither radiation capture efficiency nor carbon use efficiency were affected by elevated [CO₂], but yield increased by 13% due to a sustained increase in canopy quantum yield. CO₂ enrichment increased root mass, tiller number and seed mass. Harvest index and chlorophyll concentration were unchanged, but CO₂ enrichment increased average life cycle net photosynthesis (13%, P < 0·05) and root respiration (24%, P < 0·05). These data indicate that plant communities adapt to CO₂ enrichment through changes in C allocation. Elevated [CO₂] increases sink strength in optimal environments, resulting in sustained increases in photosynthetic capacity, canopy quantum yield and daily C gain throughout the life cycle.