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Productivity
Kinds of Productivity Terms modified by Productivity Selected AbstractsWORKFORCE COMPOSITION AND FIRM PRODUCTIVITY: EVIDENCE FROM TAIWANECONOMIC INQUIRY, Issue 4 2010JIN-TAN LIU We study the relationship between workforce composition and firm productivity based on a new employee-employer-matched data set, using an array of workforce characteristics and three alternative measures of firm productivity. While firm age is not essential for the performance of firms, those of smaller size and those in the steel and transportation industries outperform others. Moreover, labor quality, particularly the middle-aged with higher education, contributes significantly to firms' productivity. Furthermore, economic incentives and market competition both play important roles in the performance of firms. Finally, there is an employer-size premium with larger firms paying higher wages and nonwage benefits. (JEL C33, D20, J30) [source] PRODUCTIVITY AND THE PENETRATION OF INFORMATION TECHNOLOGYECONOMIC PAPERS: A JOURNAL OF APPLIED ECONOMICS AND POLICY, Issue 4 2001HUW McKAY First page of article [source] TOTAL FACTOR PRODUCTIVITY IN AUSTRALIAN EDUCATION SERVICESECONOMIC PAPERS: A JOURNAL OF APPLIED ECONOMICS AND POLICY, Issue 3 2000GEORGE VERIKIOS First page of article [source] AGGLOMERATION EXTERNALITIES, PRODUCTIVITY, AND TECHNICAL INEFFICIENCY,JOURNAL OF REGIONAL SCIENCE, Issue 4 2006Ragnar Tveteras ABSTRACT Agglomeration externalities can have positive effects on both the production possibility frontier and technical inefficiency of firms. Increased levels of localized knowledge spillovers and substitution of internal inputs with external inputs may lead to fewer errors in decision-making and execution of production tasks, thus causing firms to become technically more efficient relative to the production frontier. When we estimate a stochastic frontier production model on a large panel of salmon aquaculture farms, we find econometric support for positive agglomeration externalities on both the production frontier and technical inefficiency. [source] INVENTOR PRODUCTIVITY AND FIRM SIZE: EVIDENCE FROM PANEL DATA ON INVENTORSPACIFIC ECONOMIC REVIEW, Issue 4 2009Jinyoung Kim It has long been recognized that worker wages and productivity are higher in large firms. Moreover, economists have been interested in the efficiency of large firms in R&D enterprises. This paper uses inventor panel data to examine the relationship between inventor productivity and firm size in the pharmaceutical and semiconductor industries. In both industries, we find that inventors' productivity increases with firm size even after controlling for inventors' experience, education and other firm characteristics. We find evidence in the pharmaceutical industry that this is partly accounted for by differences in the way in which large and small firms organize R&D activities. [source] OMITTED VARIABLES, CONFIDENCE INTERVALS, AND THE PRODUCTIVITY OF EXCHANGE RATESPACIFIC ECONOMIC REVIEW, Issue 1 2007Jonathan E. Leightner This paper develops confidence intervals for BD-RTPLS and uses BD-RTPLS to estimate the relationship between the exchange rate (e) and gross domestic product (GDP) using annual data from 1984 to 2000 for 23 developing Asian and Pacific countries. BD-RTPLS produces estimates for the exchange rate multiplier (dGDP/de) for these countries and shows how omitted variables affected these multipliers across countries and over time. [source] EXPORTING AND PRODUCTIVITY: A FIRM-LEVEL ANALYSIS OF THE TAIWAN ELECTRONICS INDUSTRYTHE DEVELOPING ECONOMIES, Issue 3 2003Chih-Hai YANG Based on the panel data of Taiwanese electronics firms, this paper explores the relationship between exporting and productivity. Contemporaneous levels of exports and productivity are indeed positively correlated. The causality tests show causality from productivity to exporting and vice versa, implying that self-selection and learning-by-exporting effects coexist in the Taiwan electronics industry, while the learning-by-exporting effect is less supported. Exporting also has a positive impact on the productivity growth of firms, while the effect diminishes gradually after entering foreign markets. Decomposing the productivity growth shows that the reallocation effect accounts for only 20 per cent compared to the own-effect share of 80 per cent, which is mostly contributed by firms that continually export. [source] TYPES OF PUBLIC CAPITAL AND THEIR PRODUCTIVITY IN JAPANESE PREFECTURES*THE JAPANESE ECONOMIC REVIEW, Issue 2 2008IZUMI MIYARA Several researchers have studied the productivity of public capital in Japan but most have not paid attention to the types of public infrastructure or differences in production technology between prefectures. We estimate prefectural production functions with differently aggregated public capital. Through the model selection process, we examine the types of productive public capital. The empirical results show the production technologies used and how types of productive public capital differ between prefectures. [source] PRODUCTIVITY AND BUSINESS CYCLES IN JAPAN: EVIDENCE FROM JAPANESE INDUSTRY DATA,THE JAPANESE ECONOMIC REVIEW, Issue 2 2006T. MIYAGAWA Constructing a database of 37 industries, we examine whether the measured productivity in Japan is pro-cyclical and investigate the sources of this pro-cyclicality by using the production function approach employed by Hall (1990) and Basu and Fernald (1995). The aggregate Solow residual displays pro-cyclicality. A large number of industries show constant returns to scale. No significant evidence for the presence of thick-market externalities is found. Our results also hold when we consider labour hoarding, part-time employment, and the adjustment cost of investment. The results indicate that policies to revitalize the Japanese economy should concentrate on promoting productivity growth. [source] COMMENT: PRODUCTIVITY AND BUSINESS CYCLES IN JAPAN: EVIDENCE FROM JAPANESE INDUSTRY DATA,THE JAPANESE ECONOMIC REVIEW, Issue 2 2006TOMOYUKI NAKAJIMA First page of article [source] EFFECTS OF TECHNOLOGY ADOPTION ON PRODUCTIVITY AND INDUSTRY GROWTH: A STUDY OF STEEL REFINING FURNACES,THE JOURNAL OF INDUSTRIAL ECONOMICS, Issue 3 2008TSUYOSHI NAKAMURA This paper examines the impact of new technology on plant-level productivity in the Japanese steel industry during the 1950's and 1960's. We estimate the production function, considering the differences in technology between the refining furnaces owned by a plant. We find that a more productive plant was likely to adopt the new technology and that the adoption would be expected to occur immediately following the peak of the productivity level achieved with the old technology. The adoption of the new technology primarily accounted not only for the industry's productivity slowdown but also for the industry's remarkable growth. [source] PRODUCTIVITY AND LABOUR DEMAND EFFECTS OF INWARD AND OUTWARD FOREIGN DIRECT INVESTMENT ON UK INDUSTRY*THE MANCHESTER SCHOOL, Issue 2 2009NIGEL DRIFFIELD We relate the technological and factor price determinants of inward and outward foreign direct investment (FDI) to its potential productivity and labour market effects on both host and home economies. This allows us to distinguish clearly between technology-sourcing and technology-exploiting FDI, and to identify FDI that is linked to labour cost differentials. We then empirically examine the effects of different types of FDI into and out of the UK on domestic (i.e. UK) productivity and on the demand for skilled and unskilled labour at the industry level. [source] COLONIALISM AND INDUSTRIALISATION: FACTORY LABOUR PRODUCTIVITY OF COLONIAL KOREA, 1913,37AUSTRALIAN ECONOMIC HISTORY REVIEW, Issue 1 2008Duol Kim colonial Korea; colonialism; entrepreneurship; factory labour productivity; industrialisation Unlike other colonial economies, Korea industrialised rapidly during its colonial period, which past scholars attributed to the industrialisation policy directed by the Japanese colonial government between 1930 and 1945. Our analysis of factory labour productivity from 1913 to 1937 suggests significant revisions to this claim. Factory labour productivity as well as total production grew rapidly before the active intervention of the colonial government. In addition, Korean entrepreneurs invested heavily in their firms and successfully competed with Japanese entrepreneurs. We conjecture that the pre-war experience of Korean entrepreneurs provided a critical foundation for the post-colonial economic growth. [source] RESEARCH PRODUCTIVITY OF AUSTRALIAN ACADEMIC ECONOMISTS: HUMAN-CAPITAL AND FIXED EFFECTS,AUSTRALIAN ECONOMIC PAPERS, Issue 1 2007JOAN R. RODGERS This study investigates why some economics departments in Australian universities are more research productive than others. The hypothesis is simple: research productivity depends upon the human capital of department members and the department-specific conditions under which they work. A Tobit model is used to estimate the magnitude of the two effects. Both are found to be important. Our results help explain why a small number of departments consistently outperform the others in studies that rank Australian economics departments according to research output. [source] Service Businesses and Productivity,DECISION SCIENCES, Issue 3 2004Roger W. Schmenner ABSTRACT The records of superior performance of selected service firms over many years suggest that they may be more productive than others. This article uses the Theory of Swift, Even Flow to explain why that might be true. In the process, this article improves Schmenner's 1986 service process matrix. The redefinition of the axes of this matrix and of the resulting diagonal leads to enhanced understanding of productivity for service operations and helps to explain how some leading service companies have been able to sustain their competitive positions for decades. [source] Severity of anxiety and work-related outcomes of patients with anxiety disordersDEPRESSION AND ANXIETY, Issue 12 2009Steven R. Erickson PharmD. Abstract Background: This study examined associations between anxiety and work-related outcomes in an anxiety disorders clinic population, examining both pretreatment links and the impact of anxiety change over 12 weeks of treatment on work outcomes. Four validated instruments were used to also allow examination of their psychometric properties, with the goal of improving measurement of work-related quality of life in this population. Methods: Newly enrolled adult patients seeking treatment in a university-based anxiety clinic were administered four work performance measures: Work Limitations Questionnaire (WLQ), Work Productivity and Activity Impairment Questionnaire (WPAI), Endicott Work Productivity Scale (EWPS), and Functional Status Questionnaire Work Performance Scale (WPS). Anxiety severity was determined using the Beck Anxiety Inventory (BAI). The Clinical Global Impressions, Global Improvement Scale (CGI-I) was completed by patients to evaluate symptom change at a 12-week follow-up. Two severity groups (minimal/mild vs. moderate/severe, based on baseline BAI score) were compared to each other on work measures. Results: Eighty-one patients provided complete baseline data. Anxiety severity groups did not differ in job type, time on job, job satisfaction, or job choice. Patients with greater anxiety generally showed lower work performance on all instruments. Job advancement was impaired for the moderate/severe group. The multi-item performance scales demonstrated better validity and internal consistency. The WLQ and the WPAI detected change with symptom improvement. Conclusion: Level of work performance was generally associated with severity of anxiety. Of the instruments tested, the WLQ and the WPAI questionnaire demonstrated acceptable validity and internal reliability. Depression and Anxiety, 2009. Š 2009 Wiley-Liss, Inc. [source] Safety Nets and Opportunity Ladders: Addressing Vulnerability and Enhancing Productivity in South AsiaDEVELOPMENT POLICY REVIEW, Issue 5 2002Naila Kabeer As patterns of poverty and vulnerability in South Asia change, households have to balance immediate needs and long,term goals. For the poor, these choices, and the costs of precautionary measures, are particularly acute and call for suitable government policies. While policy,makers face a number of trade,offs between promotion, prevention and protection goals, careful design can maximise the potential to reconcile these objectives. A review of experience suggests a number of lessons regarding the relative benefits of targeted and universal programmes; the need to differentiate microfinance products for different groups amongst the poor; ways of basing the self,targeting of public works on rights rather than stigma; and the influence of political processes (such as decentralisation) for the overall effectiveness of social protection. [source] The importance of interspecific interactions for breeding-site selection: peregrine falcons seek proximity to raven nestsECOGRAPHY, Issue 6 2004Fabrizio Sergio The advent of GIS is initiating a rapid increase in the utilization of wildlife-habitat models as tools for species and habitat management. However, such models rarely include estimates of interspecific interactions among explanatory variables. We tested the importance of such variables by using the peregrine falcon Falco peregrinus, a medium-sized raptor frequently reported to be affected by heterospecifics, as a model species. In an Alpine population, compared to random locations, peregrines selected breeding sites farther from conspecifics, on taller cliffs, with higher availability of farmland and closer to raven Corvus corax nests. Within suitable habitat, peregrines selected sites near ravens and far from elevations associated with golden eagle Aquila chrysaetos nests. Productivity increased with cliff size, farmland availability (rich in the local main prey) and with proximity to ravens, suggesting that the observed choices were adaptive. Finally, at the regional level, peregrine density peaked at low elevation and was positively associated with raven density. The results suggested an active breeding association of peregrines with ravens, which may provide early-warning cues against predators and safe alternative nest-sites. They also confirmed the importance of including estimates of interspecific interactions among explanatory variables, which may: 1) make models more realistic; 2) increase their predictive power by lowering unexplained variance due to unmeasured factors; 3) provide unexpected results such as the cryptic, large-scale breeding association of our study; and 4) stimulate further hypothesis formulation and testing, ultimately leading to deeper ecological knowledge of the study system. [source] The Impact of Trade on Intra-Industry Reallocations and Aggregate Industry ProductivityECONOMETRICA, Issue 6 2003Marc J. Melitz This paper develops a dynamic industry model with heterogeneous firms to analyze the intra-industry effects of international trade. The model shows how the exposure to trade will induce only the more productive firms to enter the export market (while some less productive firms continue to produce only for the domestic market) and will simultaneously force the least productive firms to exit. It then shows how further increases in the industry's exposure to trade lead to additional inter-firm reallocations towards more productive firms. The paper also shows how the aggregate industry productivity growth generated by the reallocations contributes to a welfare gain, thus highlighting a benefit from trade that has not been examined theoretically before. The paper adapts Hopenhayn's (1992a) dynamic industry model to monopolistic competition in a general equilibrium setting. In so doing, the paper provides an extension of Krugman's (1980) trade model that incorporates firm level productivity differences. Firms with different productivity levels coexist in an industry because each firm faces initial uncertainty concerning its productivity before making an irreversible investment to enter the industry. Entry into the export market is also costly, but the firm's decision to export occurs after it gains knowledge of its productivity. [source] The Impact of the Demand for Clinical Productivity on Student Teaching in Academic Emergency DepartmentsACADEMIC EMERGENCY MEDICINE, Issue 12 2004Todd J. Berger MD Objective: Because many emergency medicine (EM) attending physicians believe the time demands of clinical productivity limit their ability to effectively teach medical students in the emergency department (ED), the purpose of this study was to determine if there is an inverse relationship between clinical productivity and teaching evaluations. Methods: The authors conducted a prospective, observational, double-blind study. They asked senior medical students enrolled in their EM clerkship to evaluate each EM attending physician who precepted them at three academic EDs. After each shift, students anonymously evaluated 10 characteristics of clinical teaching by their supervising attending physician. Each attending physician's clinical productivity was measured by calculating their total relative value units per hour (RVUs/hr) during the nine-month study interval. The authors compared the total RVUs/hr for each attending physician to the medians of their teaching evaluation scores at each ED using a Spearman rank correlation test. Results: Seventy of 92 students returned surveys, evaluating 580 shifts taught by 53 EM attending physicians. Each attending physician received an average of 11 evaluations (median score, 5 of 6) and generated a mean of 5.68 RVUs/hr during the study period. The correlation between evaluation median scores and RVUs/hr was ,0.08 (p = 0.44). Conclusions: The authors found no statistically significant relationship between clinical productivity and teaching evaluations. While many EM attending physicians perceive patient care responsibilities to be too time consuming to allow them to be good teachers, the authors found that a subset of our more productive attending physicians are also highly rated teachers. Determining what characteristics distinguish faculty who are both clinically productive and highly rated teachers should help drive objectives for faculty development programs. [source] Cyclical Productivity in Europe and the United States: Evaluating the Evidence on Returns to Scale and Input UtilizationECONOMICA, Issue 296 2007ROBERT INKLAAR This paper studies procyclical productivity growth at the industry level in the United States and three European countries (France, Germany and the Netherlands). Industry-specific demand-side instruments are used to examine the prevalence of non-constant returns to scale and unmeasured input utilization. For the aggregate US economy, unmeasured input utilization seems to explain procyclical productivity. However, this correction still leaves one in three US industries with procyclical productivity. This failure of the model can also be seen in Europe and is mostly concentrated in services industries. [source] Increasing Returns, Labour Utilization and Externalities: Procyclical Productivity in the United States and JapanECONOMICA, Issue 266 2000Michela Vecchi This paper investigates procyclical productivity and attempts to discriminate among several competing explanations. The study focuses on the United States and Japan, since the different industrial relations in these two economies serve to cast a sharper light on the procyclical productivity debate. Labour hoarding, evaluated through the introduction of a labour utilization proxy, proves to be an important influence. The interpretation of the role of external economies remains an open issue. [source] Restraining the Genuine Homo Economicus: Why the Economy Cannot Be Divorced from Its GovernanceECONOMICS & POLITICS, Issue 2 2003Stergios Skaperdas The Homo economicus of traditional economics is far from being completely self-interested, rational, or as individualistic as he is purported to be; he will haggle to death over price but will not take what he wants by force. Implicitly, he is assumed to behave ruthlessly within a well-defined bubble of sainthood. Based on a simple model, I first examine what occurs when this assumption is relaxed and genuine, amoral Homo economici interact. Productivity can be inversely related to compensation; a longer shadow of the future can intensify conflict; and more competition among providers of protection reduces welfare. The patently inefficient outcomes that follow call for restraining self-interest, for finding ways to govern markets. I then review some of the different ways of creating restraints, from the traditional social contract, to the hierarchical domination of kings and lords, to modern forms of governance. Checks and balances, wider representation, the bureaucratic form of organization, and other ingredients of modern governance can partly be thought of as providing restraints to the dark side of self-interest. Though highly imperfect, these restraints are better than the alternative, which typically involves autocratic, amateurish, and corrupt rule. Then, thinking of most problems in terms of a first-best economic model is practically and scientifically misguided. [source] Influence of contamination by organochlorine pesticides and polychlorinated biphenyls on the breeding of the Spanish Imperial Eagle (Aquila adalberti)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2008Mauro Hernández Abstract We evaluated temporal and regional trends of organochlorine (OC) pesticide (including polychlorinated biphenyl [PCB]) levels in eggs of the Spanish Imperial Eagle (Aquila adalberti) collected in Spain between 1972 and 2003. Levels of p,p,-dichlorodiphenyldichloroethylene (DDE) and PCBs varied significantly (p = 0.022) among regions (central, western, and Doņana), being higher in Doņana than in the central and western populations (DDE: 1.64 ą 5.56, 0.816 ą 1.70, and 1.1 ą 2.66 ,g/g, respectively; PCBs: 1.189 ą 5.0, 0.517 ą 1.55, and 0.578 ą 1.75 ,g/g, respectively). Levels of DDE decreased with time, but a significant interaction was observed between region and time. In Doņana, egg volume and breadth as well as Ratcliffe Index were significantly lower after DDT use (p = 0.0018) than during the pre-DDT period (p = 0.0018); eggs were significantly smaller overall than in the other two regions (p = 0.04) and were smaller when DDE levels increased, even when controlling for regional differences (p = 0.04). Productivity in Doņana was significantly lower than in the other regions (p < 0.001). Clutch size in Doņana varied according to DDE concentrations (p = 0.01), with the highest DDE concentrations found in clutches consisting of one egg. When considering eggs with DDE levels greater than 3.5 ,g/g, a significant effect of DDE on fertility was found (p = 0.03). Clutches with DDE levels greater than 4.0 ,g/g had a higher probability of hatching failure (p = 0.07) and produced fewer fledglings (p = 0.03). If we consider 3.5 ,g/g as the lowest-observable-adverse-effect level, the proportion of sampled clutches that exceeded that level in Doņana (29%) was significantly higher than in other regions (p < 0.001). These eggs showed a mean percentage of thinning of 16.72%. Contamination by OCs, mainly DDE, could explain, at least in part, the low productivity of the Spanish Imperial Eagles in Doņana. [source] Changes in productivity and contaminants in bald eagles nesting along the lower Columbia River, USAENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 7 2005Jeremy A. Buck Abstract Previous studies documented poor productivity of bald eagles (Haliaeetus leucocephalus) in the lower Columbia River (LCR), USA, and elevated p,p,-dichlorodiphenyldichloroethylene (DDE), polychlorinated biphenyls (PCBs), dioxins, and furans in eagle eggs. From 1994 to 1995, we collected partially incubated eggs at 19 of 43 occupied territories along the LCR and compared productivity and egg contaminants to values obtained in the mid-1980s. We found higher productivity at new nesting sites along the river, yet productivity at 23 older breeding territories remained low and was not different (p = 0.713) between studies. Eggshell thickness at older territories had not improved (p = 0.404), and eggshells averaged 11% thinner than shells measured before dichlorodiphenyltrichloroethane use. Decreases in DDE (p = 0.022) and total PCBs (p = 0.0004) in eggs from older breeding areas occurred between study periods. Productivity was not correlated to contaminants, but DDE, PCBs, and dioxin-like chemicals exceeded estimated no-effect values. Some dioxin-like contaminants in eggs were correlated to nest location, with highest concentrations occurring toward the river's mouth where productivity was lowest. Although total productivity increased due to the success of new nesting pairs in the region, egg contaminants remain high enough to impair reproduction at older territories and, over time, may alter productivity of new pairs nesting near the river's mouth. [source] Productivity of American robins exposed to polychlorinated biphenyls, Housatonic River, Massachusetts, USAENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2003Miranda H. Henning Abstract American robins (Turdus migratorius) breeding in the Housatonic River (MA, USA) watershed were studied in the field in 2001 to determine whether productivity was adversely affected by exposure to polychlorinated biphenyls (PCBs), as would be suggested by extrapolation from laboratory studies on other avian species. The study involved identifying nests within the Housatonic River floodplain (target area) and in reference areas beyond foraging distance of the floodplain, monitoring clutch size and number hatched and fledged, collecting eggs and nestlings for analysis for PCBs, and testing for differences in productivity between populations. One hundred and six active robin nests were monitored. Although concentrations of PCBs in target specimens were more than two orders of magnitude greater than in reference specimens, the only statistically significant differences in productivity were inconsistent with an exposure-related effect. First-generation productivity of exposed robins was within the range of natural background variation. Bioequivalence tests confirmed that first-generation productivity was statistically and biologically equivalent in target and reference robins. These findings contrast with extrapolations from laboratory studies of other avian species. [source] Life Cycle and Cohort Productivity in Economic Research: The Case of GermanyGERMAN ECONOMIC REVIEW, Issue 4 2008Michael Rauber Research productivity; life cycles; cohort effects Abstract. We examine the research productivity of German academic economists over their life cycles. It turns out that the career patterns of research productivity as measured by journal publications are characterized by marked cohort effects. Moreover, the life cycles of younger German economists are hump shaped and resemble the life cycles identified for US economists, whereas the life cycles of older German economists are much flatter. Finally, we find that not only productivity, but also research quality follows distinct life cycles. Our study employs econometric techniques that are likely to produce estimates that are more trustworthy than previous estimates. [source] Convergence in Structure and Productivity in European Manufacturing?GERMAN ECONOMIC REVIEW, Issue 1 2004Klaus Gugler Structural convergence; productivity convergence; growth of industries; European integration Abstract. We find fast convergence in productivity for 99 three-digit European industries over the 1985,98 period. Half of any productivity gap is closed on average in about 10,15 years. We explicitly formulate the steady-state assumptions for structural convergence to hold. Convergence in industrial structure is much slower than productivity catch-up with a half-life of around 50 years, a stylized fact which cannot easily be explained by the existing models of trade and growth. [source] Catching-up of East German Labour Productivity in the 1990sGERMAN ECONOMIC REVIEW, Issue 3 2000Ray Barrell We provide empirical evidence for exogenous and endogenous catching-up of East German labour productivity to West German levels. We argue that labour productivity in East Germany has caught up faster than has happened elsewhere. The sudden formation of the German Monetary Union was followed by large transfers to East Germany, migration of workers to West Germany, reorganization and privatization of East German firms. This has quickly led to a partial closing of the organizational, idea and object gaps that existed between East and West Germany. This paper analyses labour productivity in East and West Germany using both aggregate German data and unbalanced panel analysis of developments in East and West Germany. Factors affecting the organization of production, and especially privatization and ,foreign' firms, are found to be particularly important in this context. [source] Productivity of high-latitude lakes: climate effect inferred from altitude gradientGLOBAL CHANGE BIOLOGY, Issue 5 2005Jan Karlsson Abstract Climate change is predicted to be dramatic at high latitudes. Still, climate impact on high latitude lake ecosystems is poorly understood. We studied 15 subarctic lakes located in a climate gradient comprising an air temperature difference of about 6°C. We show that lake water productivity varied by one order of magnitude along the temperature gradient. This variation was mainly caused by variations in the length of the ice-free period and, more importantly, in the supply of organic carbon and inorganic nutrients, which followed differences in terrestrial vegetation cover along the gradient. The results imply that warming will have rapid effects on the productivity of high latitude lakes, by prolongation of ice-free periods. However, a more pronounced consequence will be a delayed stimulation of the productivity following upon changes of the lakes terrestrial surroundings and subsequent increasing input of elements that stimulate the production of lake biota. [source] | ||||||||||||||||||||||||||||||||||||||||||||||||||||