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Change Point Analysis to Detect the Effect of Pruning Severity on Tree Growth
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作者 Yutaka Iguchi 《Open Journal of Forestry》 2024年第1期67-73,共7页
The effect of pruning severity on tree growth was analyzed by change point detection using segmented regression. The present study applied this analysis to a well-known published data set including diameter growth res... The effect of pruning severity on tree growth was analyzed by change point detection using segmented regression. The present study applied this analysis to a well-known published data set including diameter growth response, tree age, pruning severity and pretreatment crown size. First, multiple regression analysis was performed to assess the effect of tree age, pruning severity and pretreatment crown size on diameter growth response. Next, segmented regression analysis was performed to assess the effect of pruning severity on diameter growth response. The results of the multiple regression showed that diameter growth response was significantly influenced by pruning severity and pretreatment crown size. The results of the segmented regression showed that in the whole data set, an abrupt change toward a decrease in diameter growth response was detected at 25% of the live crown removed. However, in the group of fully crowned and open-grown, diameter growth response continuously decreased with increasing pruning severity with no significant abrupt change, whereas in the group of 70% - 90% live crown, diameter growth response did not significantly decrease up to the break point (53% crown removed) and then abruptly decreased. This may be the first study to show the numerical evaluation of the effect of pruning severity on tree growth by change point analysis. 展开更多
关键词 Regression Analysis Crown Removal Limit Tree growth PRETREATMENT Abrupt change
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Cointegration analysis with structural changes between consumption and economic growth in China 被引量:3
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作者 郭建平 何建敏 《Journal of Southeast University(English Edition)》 EI CAS 2006年第2期238-241,共4页
In order to investigate the existence of a stable long-run equilibrium relationship between economic growth and consumption in China, the relationship between the gross domestic product (GDP) and consumption in Chin... In order to investigate the existence of a stable long-run equilibrium relationship between economic growth and consumption in China, the relationship between the gross domestic product (GDP) and consumption in China was investigated by the cointegration analysis method. Using the Engle-Granger (EG) test and considering the possibility of structural changes, the impact of external economic shocks on the long-run equilibrium relationship between economic growth and consumption in China was analyzed. Analysis results show that without considering structural changes, the EG test cannot detect cointegration in the series subjected to structural changes; in considering structural changes, cointegration is successfully detected by specifying the dummy variable. In addition, the error correction models were constructed in different periods. This study verifies the existence of a long-run equilibrium relationship between economic growth and consumption in China, and this relationship has significantly changed in 1989 and 1997, respectively. 展开更多
关键词 cointegration with structural changes economic growth dummy variable CONSUMPTION error correction model
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Population growth,economic growth,technology changes in relation to environmental changes──A theoretical modelling analysis of environmental changes 被引量:2
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作者 Hu Angang(Research Center for Eco-Environmental Sciences ,Chinese Acaderny of Sciences. Beijing 100085 , China) 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1994年第4期412-421,共10页
This paper mainly deals with the impact of three major factors , namely population growth,economic growth and technology changes, on the changes of environmental quality. It presents a curve ofenvironmental changes in... This paper mainly deals with the impact of three major factors , namely population growth,economic growth and technology changes, on the changes of environmental quality. It presents a curve ofenvironmental changes in relation to demographic transition and process of industrialization. It concludesthat a major way of improving environmental quality is to intensify pollution decreasing technical factorsand that control of population growth will also reduce the pressure on the environment. 展开更多
关键词 Population growth economic growth environmental changes ttchnolilgy change.
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Discrete Software Reliability Growth Modeling for Errors of Different Severity Incorporating Change-point Concept 被引量:4
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作者 D.N.Goswami Sunil K.Khatri Reecha Kapur 《International Journal of Automation and computing》 EI 2007年第4期396-405,共10页
Several software reliability growth models (SRGM) have been developed to monitor the reliability growth during the testing phase of software development. In most of the existing research available in the literatures... Several software reliability growth models (SRGM) have been developed to monitor the reliability growth during the testing phase of software development. In most of the existing research available in the literatures, it is considered that a similar testing effort is required on each debugging effort. However, in practice, different types of faults may require different amounts of testing efforts for their detection and removal. Consequently, faults are classified into three categories on the basis of severity: simple, hard and complex. This categorization may be extended to r type of faults on the basis of severity. Although some existing research in the literatures has incorporated this concept that fault removal rate (FRR) is different for different types of faults, they assume that the FRR remains constant during the overall testing period. On the contrary, it has been observed that as testing progresses, FRR changes due to changing testing strategy, skill, environment and personnel resources. In this paper, a general discrete SRGM is proposed for errors of different severity in software systems using the change-point concept. Then, the models are formulated for two particular environments. The models were validated on two real-life data sets. The results show better fit and wider applicability of the proposed models as to different types of failure datasets. 展开更多
关键词 Discrete software reliability growth model non-homogeneous Poisson process fault severity change point probability generating function.
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Distribution Prediction of Suitable Growth Area for Eucommia ulmoides in China under Climatic Change Background 被引量:3
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作者 Yang Liu 《Meteorological and Environmental Research》 CAS 2013年第8期21-24,共4页
[ Objective] The research aimed to study distribution prediction of suitable growth area for Eucommia ulmoides in China under climatic change background. [ Method] By using the maximum entropy model and many kinds of ... [ Objective] The research aimed to study distribution prediction of suitable growth area for Eucommia ulmoides in China under climatic change background. [ Method] By using the maximum entropy model and many kinds of climate change scenarios, we predicted current and future distribution pattems of suitable growth area for Eucommia ulmoides in China and its change process. [ Result ] At present, highly suitable growth area of E. ulmoides mainly distributed in Sichuan, Shaanxi and Chongqing, Under climate change background, total suitable growth areas in future three decades all drastically reduced when compared with that at present. It was noteworthy that moderately and highly suitable growth areas of wild E. ulmoides all disappeared, and junction between Shaanxi and Gansu and Taibai Mountain would be stable suitable growth area of wild E. ulmoides. [ Condusioa] The research could provide useful reference data for investigation, protection and sustainable development of the wild E. ulmoides resources. 展开更多
关键词 E. ulmoides Suitable growth area Climate change The maximum entropy model Distribution prediction China
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Divergent responses of Picea crassifolia Kom.in different forest patches to climate change in the northeastern Tibetan Plateau
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作者 Zhongtong Peng Qifeng Mo +5 位作者 Liangjun Zhu Qingao Lu Jiaqing Cai Mingming Guo Kun Xu Yuandong Zhang 《Forest Ecosystems》 SCIE CSCD 2023年第6期752-762,共11页
Global climate changes have significantly affected tree growth and forest structures and functions in some arid and semi-arid regions,which are becoming warmer and wetter.Due to natural factors such as climate and ter... Global climate changes have significantly affected tree growth and forest structures and functions in some arid and semi-arid regions,which are becoming warmer and wetter.Due to natural factors such as climate and terrain,some tree species may form different forest patches at the edges of their distribution areas.However,how forest patches of various sizes respond to climate change is unclear.In this study,we collected 203 tree cores from six different sizes of forest patches at the edge of the distribution area of Picea crassifolia Kom.in the northeast Tibetan Plateau.And we used the dendrochronology method to study the response of tree growth and resilience in different forest patches to climate change from 1961 to 2020.We simultaneously measured the contents of nonstructural carbohydrates(NSC),total nitrogen and total phosphorus of tree needles.Our results showed that the growth of trees in small-and medium-size forest patches(0.8–18.6 ha)has increased significantly.The early growing season(May–July)minimum temperature was the most important climate factor driving the growth of small-and medium-sized patch trees.The early growing season maximum temperature was the most important climate factor that inhibited the growth of trees in the largest patches(362.8 ha).The growth of individual trees in medium forest patches was better and the correlation with annual minimum temperature,maximum temperature,precipitation,actual evapotranspiration,and palmer drought severity index was stronger.The higher NSC content,stronger photosynthesis,and higher nitrogen utilization efficiency in leaves might be one of the reasons for the better growth of trees in moderate forest patches.In extreme drought years,as the forest patch area increased,the overall trend of tree growth resistance showed a unimodal pattern,with the highest at a forest patch area of 7.1 ha,while the overall trend of tree growth recovery was opposite.Therefore,we should strengthen the management of trees in large forest patches to cope with climate change. 展开更多
关键词 Climate change Picea crassifolia Kom Forest patches Tree growth RESILIENCE
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Climate change evidence in tree growth and stand productivity at the upper treeline ecotone in the Polar Ural Mountains 被引量:3
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作者 Nadezhda M.Devi Vladimir V.Kukarskih +2 位作者 Аrina A.Galimova Valeriy S.Mazepa Andrey A.Grigoriev 《Forest Ecosystems》 SCIE CSCD 2020年第1期76-91,共16页
Background:Recent warming is affecting species composition and species areal distribution of many regions.However,although most treeline studies have estimated the rates of forest expansion into tundra,still little is... Background:Recent warming is affecting species composition and species areal distribution of many regions.However,although most treeline studies have estimated the rates of forest expansion into tundra,still little is known about the long-term dynamic of stand productivity at the forest-tundra intersection.Here,we make use of tree-ring data from 350 larch(Larix sibirica Ledeb.)and spruce(Picea obovata Ledeb.)sampled along the singular altitudinal treeline ecotone at the Polar Urals to assess the dynamic of stand establishment and productivity,and link the results with meteorological observations to identify the main environmental drivers.Results:The analysis of stand instalment indicated that more than 90%of the living trees appeared after 1900.During this period,the stand became denser and moved 50m upward,while in recent decades the trees of both species grew faster.The maximum afforestation occurred in the last decades of the twentieth century,and the large number of encountered saplings indicates that the forest is still expanding.The upward shift coincided with a slight increase of May-August and nearly doubling of September-April precipitation while the increase in growth matched with an early growth season warming(June+0.27°C per decade since 1901).This increase in radial growth combined with the stand densification led to a 6-90 times increase of biomass since 1950.Conclusion:Tree-ring based twentieth century reconstruction at the treeline ecotone shows an ongoing forest densification and expansion accompanied by an increased growth.These changes are driven by climate change mechanism,whereby the leading factors are the significant increase in May-June temperatures and precipitation during the dormant period.Exploring of phytomass accumulation mechanisms within treeline ecotone is valuable for improving our understanding of carbon dynamics and the overall climate balance in current treeline ecosystems and for predicting how these will be altered by global change. 展开更多
关键词 POLAR URALS TREELINE PRODUCTIVITY Climate change Radial growth Recruitment LARCH Spruce
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Investigating the causes of Lake Urmia shrinkage:climate change or anthropogenic factors?
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作者 Mehri SHAMS GHAHFAROKHI Sogol MORADIAN 《Journal of Arid Land》 SCIE CSCD 2023年第4期424-438,共15页
In the current scenario,Lake Urmia,one of the vastest hyper saline lakes on the Earth,has been affected by serious environmental degradation.Using different satellite images and observational data,this study investiga... In the current scenario,Lake Urmia,one of the vastest hyper saline lakes on the Earth,has been affected by serious environmental degradation.Using different satellite images and observational data,this study investigated the changes in the lake for the period 1970–2020 based on the effects of climate change and several human-induced processes on Lake Urmia,such as population growth,excessive dam construction,low irrigation water use efficiency,poor water resources management,increased sediment flow into the lake,and lack of political and legal frameworks.The results indicated that between 1970 and 1997,the process of change in Lake Urmia was slow;however;the shrinkage was faster between 1998 and 2018,with about 30.00%of the lake area disappearing.As per the findings,anthropogenic factors had a much greater impact on Lake Urmia than climate change and prolonged drought;the mismanagement of water consumption in the agricultural sector and surface and underground water withdrawals in the basin have resulted in a sharp decrease in the lake's surface.These challenges have serious implications for water resources management in Lake Urmia Basin.Therefore,we provided a comprehensive overview of anthropogenic factors on the changes in Lake Urmia along with existing opportunities for better water resources management in Lake Urmia Basin.This study serves as a guideline framework for climate scientists and hydrologists in order to assess the effects of different factors on lake water resources and for decision-makers to formulate strategies and plans according to the management task. 展开更多
关键词 Lake Urmia lake shrinkage climate change population growth dam construction water resources management
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Study on the Future Climate Change and Its Influence on the Growth Stage and Yield of Wheat in Weifang City 被引量:1
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作者 Jing YUAN Jianping XU +2 位作者 Lijuan SUN Xiuzhen ZHANG Xiaoli WANG 《Asian Agricultural Research》 2015年第3期82-84 98,98,共4页
In order to study the trend of climate change in the future in Weifang,and analyze the impact of climate change on the local wheat production,the air temperature and precipitation in Weifang from 2021 to 2050 were sim... In order to study the trend of climate change in the future in Weifang,and analyze the impact of climate change on the local wheat production,the air temperature and precipitation in Weifang from 2021 to 2050 were simulated by using the regional climate model PRECIS.And then put the meteorological data into the crop model to simulate the growth of wheat under climate change conditions in the future.The results showed that there would be a trend of rising temperature and increasing precipitation in Weifang in the future.Climate warming would result in growth period of wheat to be ahead of schedule and yield reduction.If taking into account the effect of CO2,the yield of wheat would increase. 展开更多
关键词 CLIMATE change WHEAT growth STAGE YIELD Impact
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Study on the Influence of Climatic Change on Pasture Growth in Inner Mongolia Grassland 被引量:1
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作者 Li Xinghua Liu Xiurong +1 位作者 Cao Yanfang Sun Xiaolong 《Meteorological and Environmental Research》 CAS 2014年第5期43-47,52,共6页
Through analyzing statistically metrological observation data from 1971 to 2010 and pasture data from 1983 to 2012 at 6 animal husbandry meteorological testing stations of Inner Mongolia grassland, the conclusions wer... Through analyzing statistically metrological observation data from 1971 to 2010 and pasture data from 1983 to 2012 at 6 animal husbandry meteorological testing stations of Inner Mongolia grassland, the conclusions were drawn. Those were that annual average temperature rose in a straight line in Inner Mongolia grassland, and the increase rates of annual average temperature in meadow steppe and typical steppe were 0.40 and 0.34 ℃/10 a respectively. Annual rainfall had 10-year cyclical characteristics, and precipitation in the 1990s was the most but reduced significantly after 2000. Climate experienced the cold wet -cold dry -warm wet -warm dry periods. Warm and dry climate made the average heights of pasture in meadow steppe and typical steppe of Inner Mongolia cut down 2.4 and 9.3 cm in nearly 12 years than that in the 1990s; the average coverage of herbage decreased by 11% and 13%; the average hay yields reduced by 1 019.8 and 671.4 kg/hm^2. 展开更多
关键词 Climatic change Pasture growth period Pasture height Grass coverage Hay yield China
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Polyneuropathy organomegaly endocrinopathy M-protein and skin changes syndrome with ascites as an early-stage manifestation:A case report
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作者 Xiao-Lei Zhou Ying-Hao Chang +5 位作者 Lan Li Juan Ren Xiao-Ling Wu Xue Zhang Peng Wu Shan-Hong Tang 《World Journal of Clinical Cases》 SCIE 2023年第1期135-142,共8页
BACKGROUND Polyneuropathy organomegaly endocrinopathy M-protein and skin changes(POEMS)syndrome is a rare paraneoplastic syndrome caused by a potential plasma cell tumor.The clinical manifestations of POEMS syndrome a... BACKGROUND Polyneuropathy organomegaly endocrinopathy M-protein and skin changes(POEMS)syndrome is a rare paraneoplastic syndrome caused by a potential plasma cell tumor.The clinical manifestations of POEMS syndrome are diverse.Due to the insidious onset and lack of specific early-stage manifestations,POEMS syndrome is easily misdiagnosed or never diagnosed,leading to delayed treatment.Neurological symptoms are usually the first clinical manifestation,while ascites is a rare symptom in patients with POEMS syndrome.CASE SUMMARY A female patient presented with unexplained ascites as an initial symptom,which is a rare early-stage manifestation of the condition.After 1 year,the patient gradually developed progressive renal impairment,anemia,polyserosal effusion,edema,swollen lymph nodes on the neck,armpits,and groin,and decreased muscle strength of the lower extremities.The patient was eventually diagnosed with POEMS syndrome after multidisciplinary team discussion.Treatment comprised bortezomib+dexamethasone,continuous renal replacement therapy,chest and abdominal closed drainage,transfusions of erythrocytes and platelets,and other symptomatic and supportive treatments.The patient’s condition initially improved after treatment.However,then her symptoms worsened,and she succumbed to the illness and died.CONCLUSION Ascites is a potential early manifestation of POEMS syndrome,and this diagnosis should be considered for patients with unexplained ascites.Furthermore,multidisciplinary team discussion is helpful in diagnosing POEMS syndrome. 展开更多
关键词 Polyneuropathy organomegaly endocrinopathy M-protein and skin changes syndrome ASCITES Early-stage manifestation Neurogenic damage Vascular endothelial growth factor Case report
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Climate Change and Its Adverse Impacts on Plant Growth in South Asia:Current Status and Upcoming Challenges 被引量:1
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作者 Mohammad Saidur Rhaman Tahjib-Ul-Arif +1 位作者 Mohammad Golam Kibria Anamul Hoque 《Phyton-International Journal of Experimental Botany》 SCIE 2022年第4期695-711,共17页
Socioeconomic development,adaptive capacity of the population,and demographic conditions across the states of South Asia make it more vulnerable to climate change.South Asia is daily going to be more vulnerable to cli... Socioeconomic development,adaptive capacity of the population,and demographic conditions across the states of South Asia make it more vulnerable to climate change.South Asia is daily going to be more vulnerable to climate change and climatic variability.This region is facing multiple challenges in terms of climate change,dilapidation of ecosystems,and food insecurity.Climate is the primary determining factor for agricultural output,which unswervingly influences food production across the globe.South Asia is mainly an agricultural foundation based region and thus the economy of these regions directly depends on agriculture and agricultural production.Due to the extensive dependence on natural assets for thriving,it makes the people of this region more vulnerable to climate change.This region is now under serious risk from sea-level rising and growing incidences of extreme events such as flash floods,enhanced temperature,drought,salinity,cyclones,storms,landslides,and irregularity of precipitation.These abiotic stresses continuously disturb plant growth and productivity.It is now the time to take urgent action on these issues towards a sustainable,inclusive and resource efficient way to overcome this.In this review,we summarize the overall situation of climate change in the South Asian countries and their adverse consequences on plants,and upcoming challenges towards a sustainable production. 展开更多
关键词 Climate change South Asia plant growth abiotic stress food security
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Changes in Environmental Parameters and Their Impact on Forest Growth in Northern Eurasia 被引量:1
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作者 Olga Khabarova Igor Savin 《Atmospheric and Climate Sciences》 2015年第2期91-105,共15页
We performed an empirical investigation of forest growth for two types of forests in northern Eurasia (larches and spruces) in order to show that the sensitivity of trees to the variable climate and geomagnetic field ... We performed an empirical investigation of forest growth for two types of forests in northern Eurasia (larches and spruces) in order to show that the sensitivity of trees to the variable climate and geomagnetic field can be seen even under the large-scale average. The main purpose of this research was to model a forest growth rate V for each forest type on the basis of several environmental parameters influencing the tree growth in a high degree and to find the differences and similarities of the larches and spruces’ response to changing environment. We showed that V, which is related to the annual tree-ring width, could be derived from the Normalized Difference Vegetation Index (NDVI) data. Averaged yearly by species for 1982-2006, it displayed a long-term decrease (most likely related to the global climate change) as well as short-term variations with periods of 2.2, 4 and 8 years. A composite function method was used for modeling. We selected several tree growth drivers (the temperature, precipitation, insolation and the geomagnetic field intensity) that were highly correlated with V, and a function was modeled that described the behavior of V. The correlation coefficients between the derived function and experimental time series were 0.8 for larches and 0.9 for spruces. Compared with spruces, larches demonstrated higher thermo-sensitivity. A loss of tree sensitivity to temperature changes is puzzling for dendroclimatology, as a similar process might have occurred during previous periods of sharp global climate changes (as observed currently). Sensitivity of trees to geomagnetic field changes is confirmed both at long- and short-timescales. Spruces are found to be more magnetosensitive than larches. 展开更多
关键词 CLIMATE change FOREST growth BIOMAGNETISM
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Direct-Seeded Rice: Genetic Improvement of Game-Changing Traits for Better Adaption
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作者 Priyanka NEGI Jagadish RANE +10 位作者 Rajendra Sadashiv WAGH Tukaram Jayaram BHOR Dipti Digambar GODSE Priyanka JADHAV C.ANILKUMAR Dasari SREEKANTH K.SAMMI REDDY Sharad Ramrao GADAKH K.M.BORAIH C.B.HARISHA P.S.BASAVARAJ 《Rice science》 SCIE CSCD 2024年第4期417-433,共17页
The sustainability of rice production continues to be a subject of uncertainty and inquiry attributed to shifts in climatic conditions. In light of the impending climate change crisis and the high labor and water cost... The sustainability of rice production continues to be a subject of uncertainty and inquiry attributed to shifts in climatic conditions. In light of the impending climate change crisis and the high labor and water costs accompanying it, direct-seeded rice(DSR) is unquestionably one of the most practical solutions. Despite its resource and climate-friendly advantages, early maturing rice faces weed competitiveness and seedling establishment challenges. Resolving these issues is crucial for promoting its wider adoption among farmers, presenting it as a more effective sustainable rice cultivation method globally. Diverse traditional and contemporary breeding methods are employed to mitigate the limitations of the DSR approach, leveraging advanced techniques such as speed breeding and genome editing. Focusing on key traits like mesocotyl length elongation, early seedling vigor, root system architecture, and weed competitiveness holds promise for transformative improvements in DSR adaptation at a broader scale within farming communities. This review aims to summarize how these features contribute to increased crop production in DSR conditions and explore the research efforts focusing on enhancing DSR adaptation through these traits. Emphasizing the pivotal role of these game-changing traits in DSR adaptation, our analysis sheds light on their potential transformative impact and offers valuable insights for advancing DSR practices. 展开更多
关键词 climate change direct-seeded rice aerobic rice early vigor trait
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Annual growth of Fagus orientalis is limited by spring drought conditions in Iran’s Golestan Province
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作者 Khalil Ghorbani Jahangir Mohammadi Laleh Rezaei Ghaleh 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第1期128-142,共15页
Due to the lack of a uniform and accurate defi-nition of‘drought’,several indicators have been introduced based on different variables and methods,and the efficiency of each of these is determined according to their... Due to the lack of a uniform and accurate defi-nition of‘drought’,several indicators have been introduced based on different variables and methods,and the efficiency of each of these is determined according to their relationship with drought.The relationship between two drought indices,SPI(standardized precipitation index)and SPEI(standard-ized precipitation-evapotranspiration index)in different sea-sons was investigated using annual rings of 15 tree samples to determine the effect of drought on the growth of oriental beech(Fagus orientalis Lipsky)in the Hyrcanian forests of northern Iran.The different evapotranspiration calcula-tion methods were evaluated on SPEI efficiency based on Hargreaves-Samani,Thornthwaite,and Penman-Monteith methods using the step-by-step M5 decision tree regression method.The results show that SPEI based on the Penman-Monteith in a three-month time scale(spring)had similar temporal changes and a better relationship with annual tree rings(R^(2)=0.81)at a 0.05 significant level.Abrupt change and a decreasing trend in the time series of annual tree rings are similar to the variation in the SPEI based on the Penman-Monteith method.Factors affecting evapotranspiration,temperature,wind speed,and sunshine hours(used in the Penman-Monteith method),increased but precipitation decreased.Using non-linear modeling methods,SPEI based on Penman-Monteith best illustrated climate changes affecting tree growth. 展开更多
关键词 Climate change Drought index Hyrcanian forests SPEI'Annual growth rings Fagus orientalis
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On the agricultural growth and structural changes in Suzhou Wuxi Changzhou region
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作者 XIE Jie ZENG Zungu Department of Urban and Resources Studies, Nanjing University, Nanjing 210093, CHINA XIONG Ning Department of Geography, Jiangsu Normal College, Nanjing 210013, CHINA 《Journal of Geographical Sciences》 SCIE CSCD 1998年第4期76-83,共8页
s—Suzhou Wuxi Changzhou Region (Su Xi Chang) is a famous prosperous agricultural region in China. Since the early 1980s agriculture in Su Xi Chang has got constant developed, but its growth rate is lower than t... s—Suzhou Wuxi Changzhou Region (Su Xi Chang) is a famous prosperous agricultural region in China. Since the early 1980s agriculture in Su Xi Chang has got constant developed, but its growth rate is lower than the provincial average level of Jiangsu, and its structure has not changed much. Therefore it lost many in the position of agricultural areal division of labour within Jiangsu Province. The authors of this paper suggest that Su Xi Chang agriculture should perform multiple social, economic and ecological functions with the suburban and export oriented farming as the main development direction. It is also necessary to improve management and organization structure for enhancing Su Xi Chang agricultural vitality. 展开更多
关键词 agricultural growth structure change growth pattern Suzhou Wuxi changzhou.
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Changes in embryonic development,juvenile growth and physiological adaptation of the cuttlefish Sepia pharaonis in response to photoperiod manipulation
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作者 Maowang JIANG Huan CHEN +3 位作者 Shuangnan ZHOU Qingxi HAN Ruibing PENG Xiamin JIANG 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2022年第5期2012-2027,共16页
Photoperiod is a key environmental indicator for re gulating embryonic development,individual growth and physiological processes in aquatic animals.In this study,differences in embryonic development and performance of... Photoperiod is a key environmental indicator for re gulating embryonic development,individual growth and physiological processes in aquatic animals.In this study,differences in embryonic development and performance of newly hatched cuttlefish juvenile exposed to five different cycles of light:dark(L:D):constant light,18 L:6D,12 L:12D,6 L:18D cycles,and constant darkness were evaluated.Prolonged exposure to light induced an accelerated rate of embryonic development,particularly after the red-bead stage.Principal component analysis(PCA)revealed that red-bead stage,heartbeat,endoskeleton formation,pigment appear,and six increments of cuttlebone were the main factors contributing to the embryonic development.Meaning that the duration time of these five stages were significantly different when exposed to photoperiod regimes,which may determine the duration of the incubation period of the embryos.Long term light has also affected the incubation parameters with an increased rate in hatching and shortened the incubation and hatching periods in the 12-24-h day length range.However,constant light and darkness environment appeared to have a greater effect on the stress of embryonic development,mainly reflected in the yolk shed ratio and the inking rate in the egg capsule.Moreover,the increase in the day length has contributed to improve the growth and survival of juveniles in the 12-18-h day length range;however,juveniles exposed to constant light and darkness experienced worse re sults in terms of growth,tissue glycogen content,dige stive enzymes of the digestive glands,and metabolic enzymes of the muscles.These finding suggest that prolonged light exposure accelerates the process of embryonic development,maximum feeding time is not necessarily a condition of optimal growth,and inappropriate light cycles can disturb the body’s endogenous controls.Therefore,the optimal photoperiod for the embryos development and juvenile growth of Sepia pharaonis were 12 h and 12-18 h of day length,respectively.These results are useful for increasing the production of this species during embryo incubation and juveniles rearing in aquaculture practice. 展开更多
关键词 PHOTOPERIOD embryonic development growth physiological changes CUTTLEFISH
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Analysis on Change Tendency of the Precipitation Resource during Growth Period of the Conventional Crops in Plain Area before Taihang Mountains
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作者 Suqing Han Shijing Jia 《Meteorological and Environmental Research》 CAS 2013年第2期49-52,共4页
[Objective] The aim was to study change tendency of the precipitation resource during growth period of the conventional crops in plain area before Taihang Mountains. [ Method] Based on daily precipitation data at Shij... [Objective] The aim was to study change tendency of the precipitation resource during growth period of the conventional crops in plain area before Taihang Mountains. [ Method] Based on daily precipitation data at Shijiazhuang meteorological station in recent 51 years, average rainfall dudng growth periods of the 9 kinds of conventional crops was obtained. Precipitation tendency dudng growth periods of the 9 kinds of conventional crops in plain area before Taihang Mountains was analyzed by Mann-Kendall nonparametric test. [ Result] Seen from rainfall during growth pedods of the different crops, rainfall was the least during the growth period of winter wheat, followed by summer corn. Rainfall during growth peri- ods of the cotton, oil plant, vegetable, fruit tree, potato, rice and legumes was more. Under different guaranteed rates, precipitation change also had difference. Rainfall change during growth periods of the wheat and corn was bigger, and rainfall change during growth period of the rice was smaller. Change degree of the precipitation during growth periods of the cotton, oil plant, vegetable, fruit tree and legumes was equivalent, while precipitation change during growth period of the potato was the biggest. Seen from change tendency of the precipitation during growth periods of the different crops, precipitation in the growth period of winter wheat was increasing at a speed of 0.62 mm/a. However, precipitation in growth periods of the other crops had a decreasing tendency. Precipitation in the growth periods of summer corn and legumes decreased at the same speed which was 2.11 mm/a, while precipitation in growth periods of the cotton, oil plant, vegetable, fruit tree, potato and rice decreased insignificantly. [ Con dusion] The study laid foundation for determination of the agricultural irrigation water and provided theoretical reference for regional agricultural water-saving. 展开更多
关键词 Precipitation resource Conventional crops growth period change trend Plain area before Taihang Mountains China
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A Nonlinear Control Model of Growth, Risk and Structural Change
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作者 P. E. Petrakis S. Kotsios 《Intelligent Information Management》 2010年第2期80-89,共10页
Uncertainty is perceived as the means of removing the obstacles to growth through the activation of Knig- htian entrepreneurship. A dynamic stochastic model of continuous-time growth is proposed and empirically tested... Uncertainty is perceived as the means of removing the obstacles to growth through the activation of Knig- htian entrepreneurship. A dynamic stochastic model of continuous-time growth is proposed and empirically tested, including equilibrating and creative entrepreneurial activity. We find that uncertainty affects economic growth and the rate of return, and causes structural changes in portfolio shares for the two types of entrepreneurial events. Structural change depends mainly on the intertemporal rate of substitution, productiv-ity ratios, and finally intersectoral difference in return and risk. 展开更多
关键词 growth RISK ENTREPRENEURSHIP STRUCTURAL change
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Seasonal Changes Impact on Growth of Rubber (<i>Hevea brasiliensis</i>) Seedlings under Different Cultivation
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作者 Dongling Qi Guishui Xie Zhixiang Wu 《Open Journal of Forestry》 2019年第4期397-406,共10页
The vegetative growth of rubber tree is an important basis for rubber tree cultivation and economic management. Stem diameter and height growth patterns of rubber seedlings and the seasonal variability are still poorl... The vegetative growth of rubber tree is an important basis for rubber tree cultivation and economic management. Stem diameter and height growth patterns of rubber seedlings and the seasonal variability are still poorly understood. Studying the annual growth patterns and seasonal variation of rubber seedling will help understanding biological characteristics of rubber tree and provide a reference for field cultivation and management. Height growth and stem diameter of field-sown rubber seedlings cultivation and polybag-raised cultivation all displayed a distinct annual pattern of “slow-fast-slow”. Height growth and stem diameter growth response fitted the logistic equation preferably, supporting the observed pattern. Fast-growth of plant height for polybag-raised rubber seedlings cultivation and field-sown rubber seedlings cultivation occurred from June to November and May to November, respectively. This period saw the greatest accumulations of plant height growth for polybag-raised rubber seedlings cultivation and field-sown rubber seedlings cultivation accounting for 83.99% and 86.65% of total growth, respectively. Fast-growth of stem diameter for polybag-raised rubber seedlings cultivation and field-sown rubber seedlings cultivation occurred from June to November and May to November, respectively. This period saw the greatest accumulations of stem growth for polybag-raised rubber seedlings cultivation and field-sown rubber seedlings cultivation accounting for 86.71% and 84.60% of total growth, respectively. Polybag-raised rubber seedlings cultivation and field-sown rubber seedlings cultivation for the whole year had nine extension units and each month had one extension unit from May to November. Extension unit of for the whole year did not stop period and plant height growth rate has the seasonal difference. However, leaf phenophase of field-sown rubber seedlings cultivation was earlier than that of polybag-raised rubber seedlings cultivation and each extension unit of field-sown rubber seedlings cultivation was greater than that of poly-bag-raised rubber seedlings cultivation. The precipitation had the greatest impact on seedlings growth under different cultivation. There was no period annually in which height growth and stem diameter growth did not occur and the fastest growth occurred during the rainy season. Plant height and stem diameter of rubber seedlings under different cultivation showed isogony phenomenon. Extension unit and leaf phenophase of polybag-raised rubber seedlings and field-sown rubber seedlings showed consistency and synchronization characteristic. Different cultivation of rubber seedling should take corresponding measures tending management and operation. 展开更多
关键词 RUBBER (Hevea brasiliensis) Logistic Equation growth Patterns Seasonal change
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