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| 1 | Fluxes of CO_2, N_2O and CH_4 from a typical temperate grassland in Inner Mongolia and its daily variation显示文摘Using a dark enclosed chamber technique, the fluxes of CO2, N2O and CH4 from nature and disturbed grassland were measured on the spot in Inner Mongolian Temperate Grassland along the annual rainfall gradient section ranging from 450 to 200 mm. The results showed that the measured mean fluxes of CO2, N2O and CH4were (1 180.4 ±308.7), (0.010 ± 0.004) and (-0.039 ± 0.016) mg · m-2/h, respectively. The decrease of the fluxes of CO2, N2O and CH4 follows with that of annual rainfall gradient in the measurement area. Human activities, such as grazing and reclamation are also critical factors to affect the fluxes of these gases from grassland. Daily continuous measurement of CO2, N2O and CH4 fluxes showed a strong diurnal variation with higher emission in the daytime. A good relationship between the fluxes of CO2, N2O, CH4 and temperature was exposed in this study. | DONG Yunshe, ZHANG Shen, Ql Yuchun, CHEN Zuozhong & GENG Yuanbo1. Institute of Geography, Chinese Academy of Sciences, Beijing 100101, China:2, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China Correspondence should be addressed to Dong Yunshe | 2000 | Chinese Science Bulletin2000，45，17： | 66 |
| 2 | Ecosystem carbon stocks and their changes in China's grasslands显示文摘The knowledge of carbon(C) stock and its dynamics is crucial for understanding the role of grassland ecosystems in China's terrestrial C cycle.To date,a comprehensive assessment on C balance in China's grasslands is still lacking.By reviewing published literature,this study aims to evaluate ecosystem C stocks(both vegetation biomass and soil organic C) and their changes in China's grasslands.Our results are summarized as follows:(1) biomass C density(C stock per area) of China's grasslands differed greatly among previous studies,ranging from 215.8 to 348.1 g C m-2 with an average of 300.2 g C m-2.Likewise,soil C density also varied greatly between 8.5 and 15.1 kg C m-2.In total,ecosystem C stock in China's grasslands was estimated at 29.1 Pg C.(2) Both the magnitude and direction of ecosystem C changes in China's grasslands differed greatly among previous studies.According to recent reports,neither biomass nor soil C stock in China's grasslands showed a significant change during the past 20 years,indicating that grassland ecosystems are C neutral.(3) Spatial patterns and temporal dynamics of grassland biomass were closely correlated with precipitation,while changes in soil C stocks exhibited close associations with soil moisture and soil texture.Human activities,such as livestock grazing and fencing could also affect ecosystem C dynamics in China's grasslands. | Anwar MOHAMMAT | 2010 | Science China(Life Sciences)2010，53，7： | 52 |
| 3 | Biomass carbon stocks and their changes in northern China's grasslands during 1982-2006显示文摘Grassland covers approximately one-third of the area of China and plays an important role in the global terrestrial carbon(C) cycle.However,little is known about biomass C stocks and dynamics in these grasslands.During 2001-2005,we conducted five consecutive field sampling campaigns to investigate above-and below-ground biomass for northern China's grasslands.Using measurements obtained from 341 sampling sites,together with a NDVI(normalized difference vegetation index) time series dataset over 1982-2006,we examined changes in biomass C stock during the past 25 years.Our results showed that biomass C stock in northern China's grasslands was estimated at 557.5 Tg C(1 Tg=1012 g),with a mean density of 39.5 g C m-2 for above-ground biomass and 244.6 g C m-2 for below-ground biomass.An increasing rate of 0.2 Tg C yr-1 has been observed over the past 25 years,but grassland biomass has not experienced a significant change since the late 1980s.Seasonal rainfall(January-July) was the dominant factor driving temporal dynamics in biomass C stock;however,the responses of grassland biomass to climate variables differed among various grassland types.Biomass in arid grasslands(i.e.,desert steppe and typical steppe) was significantly associated with precipitation,while biomass in humid grasslands(i.e.,alpine meadow) was positively correlated with mean January-July temperatures.These results suggest that different grassland ecosystems in China may show diverse responses to future climate changes. | Anwar MOHAMMAT | 2010 | Science China(Life Sciences)2010，53，7： | 60 |
| 4 | Patterns of above-and belowground biomass allocation in China's grasslands:Evidence from individual-level observations显示文摘Above-and belowground biomass allocation not only influences growth of individual plants,but also influences vegetation structures and functions,and consequently impacts soil carbon input as well as terrestrial ecosystem carbon cycling.However,due to sampling difficulties,a considerable amount of uncertainty remains about the root:shoot ratio(R/S),a key parameter for models of terrestrial ecosystem carbon cycling.We investigated biomass allocation patterns across a broad spatial scale.We collected data on individual plant biomass and systematically sampled along a transect across the temperate grasslands in Inner Mongolia as well as in the alpine grasslands on the Tibetan Plateau.Our results indicated that the median of R/S for herbaceous species was 0.78 in China's grasslands as a whole.R/S was significantly higher in temperate grasslands than in alpine grasslands(0.84 vs.0.65).The slope of the allometric relationship between above-and belowground biomass was steeper for temperate grasslands than for alpine.Our results did not support the hypothesis that aboveground biomass scales isometrically with belowground biomass.The R/S in China's grasslands was not significantly correlated with mean annual temperature(MAT) or mean annual precipitation(MAP).Moreover,comparisons of our results with previous findings indicated a large difference between R/S data from individual plants and communities.This might be mainly caused by the underestimation of R/S at the individual level as a result of an inevitable loss of fine roots and the overestimation of R/S in community-level surveys due to grazing and difficulties in identifying dead roots.Our findings suggest that root biomass in grasslands tended to have been overestimated in previous reports of R/S. | WANG Liang*,NIU KeChang,YANG YuanHe & ZHOU Peng Department of Ecology,Key Laboratory for Earth Surface Processes of the Ministry of Education,Peking University,Beijing 100871,China. | 2010 | Science China(Life Sciences)2010，53，7： | 54 |
| 5 | Above-and belowground biomass in relation to envi- ronmental factors in temperate grasslands, Inner Mongolia显示文摘Above- and belowground biomasses of grasslands are important parameters for characterizing re- gional and global carbon cycles in grassland ecosystems. Compared with the relatively detailed in- formation for aboveground biomass (AGB), belowground biomass (BGB) is poorly reported at the re- gional scales. The present study, based on a total of 113 sampling sites in temperate grassland of the Inner Mongolia, investigated regional distribution patterns of AGB, BGB, vertical distribution of roots, and their relationships with environmental factors. AGB and BGB increased from the southwest to the northeast of the study region. The largest biomass occurred in meadow steppe, with mean AGB and BGB of 196.7 and 1385.2 g/m2, respectively; while the lowest biomass occurred in desert steppe, with an AGB of 56.6 g/m2 and a BGB of 301.0 g/m2. In addition, about 47% of root biomass was distributed in the top 10 cm soil. Further statistical analysis indicated that precipitation was the primary determinant factor in shaping these distribution patterns. Vertical distribution of roots was significantly affected by precipitation, while the effects of soil texture and grassland types were weak. | MA WenHong1,2, YANG YuanHe1, HE JinSheng1, ZENG Hui1,2 & FANG JingYun1 1 Department of Ecology, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China 2 School of Environment & Urban Study, Peking University Shenzhen Graduate School, Shenzhen 518055, China | 2008 | Science China(Life Sciences)2008，51，3： | 34 |
| 6 | Carbon budgets of three temperate forest ecosystems in Dongling Mt.,Beijing,China显示文摘There is a general agreement that forest ecosystems in the Northern Hemisphere function as signifi-cant sinks for atmospheric CO2; however, their magnitude and distribution remain large uncertainties. In this paper, we report the carbon (C) stock and its change of vegetation, forest floor detritus, and mineral soil, annual net biomass increment and litterfall production, and respiration of vegetation and soils between 1992 to 1994, for three temperate forest ecosystems, birch (Betula platyphylla) forest, oak (Quercus liaotungensis) forest and pine (Pinus tabulaeformis) plantation in Mt. Dongling, Beijing, China. We then evaluate the C budgets of these forest ecosystems. Our results indicated that total C density (organic C per hectare) of these forests ranged from 250 to 300 t C ha-1, of which 35―54 t C ha-1 from vegetation biomass C and 209―244 t C ha-1 from soil organic C (1 m depth, including forest floor detritus). Biomass C of all three forests showed a net increase, with 1.33―3.55 t C ha-1 a-1 during the study period. Litterfall production, vegetation autotrophic respiration, and soil heterotrophic respira-tion were estimated at 1.63―2.34, 2.19―6.93, and 1.81―3.49 t C ha-1 a-1, respectively. Ecosystem gross primary production fluctuated between 5.39 and 12.82 t C ha-1 a-1, about half of which (46%―59%, 3.20―5.89 t C ha-1 a-1) was converted to net primary production. Our results suggested that pine forest fixed C of 4.08 t ha-1 a-1, whereas secondary forests (birch and oak forest) were nearly in balance in CO2 exchange between the atmosphere and ecosystems. | FANG JingYun LIU GuoHua ZHU Biao WANG XiaoKe LIU ShaoHui | 2007 | Science China Earth Sciences2007，50，1： | 17 |
| 7 | Spatial-temporal variation in soil respiration and its controlling factors in three steppes of Stipa L. in Inner Mongolia, China显示文摘Grassland is the largest terrestrial ecosystem in China. It is of great significance to measure accurately the soil respiration of different grassland types for the contribution evaluation of the Chinese terrestrial ecosystem’s carbon emission to the atmospheric CO2 concentration. A three-year (2005-2007) field experiment was carried out on three steppes of Stipa L. in the Xilin River Basin, Inner Mongolia, China, using a static opaque chamber technique. The seasonal and interannual variations of soil respiration rates were analyzed, and the annual total soil respiration of the three steppes was estimated. The numerical models between soil respiration and water-heat factors were established respectively. Similar seasonal dynamic and high annual and interannual variations of soil respiration were found in all of the three steppes. In the growing season, the fluctuation of soil respiration was particularly evident. The coefficients of variation (CVs) for soil respiration in different growing seasons ranged from 54% to 93%, and the annual CVs were all above 115%. The interannual CV of soil respiration progressively decreased in the order of Stipa grandis (S. grandis) steppe > Stipa baicalensis (S. baicalensis) steppe > Stipa krylovii (S. krylovii) steppe. The annual total soil respiration for the S. baicalensis steppe was 223.62?299.24 gC m-2 a-1, 150.62-226.99 gC m-2 a-1 for the S. grandis steppe, and 111.31–131.55 gC m-2 a-1 for the S. krylovii steppe, which were consistent with the precipitation gradient. The variation in the best fitting temperature factor explained the 63.5%, 73.0%, and 73.2% change in soil respiration in the three steppes at an annual time scale, and the corresponding Q10 values were 2.16, 2.98, and 2.40, respectively. Moreover, the Q10 values that were calculated by soil temperature at different depths all expressed a 10 cm > 5 cm > surface in the three sampling sites. In the growing season, the soil respiration rates were related mostly to the surface soil moisture, and the 95.2%, 97.4%, and 93.2% variations in soil respiration in the three steppes were explained by the change in soil moisture at a depth of 0-10 cm, respectively. | QI YuChun DONG YunShe LIU LiXin LIU XingRen PENG Qin XIAO ShengSheng HE YaTing | 2010 | Science China Earth Sciences2010，53，5： | 12 |
| 8 | Experiencing winter for spring flowering: A molecular epigenetic perspective on vernalization显示文摘Many over-wintering plants, through vernalization, overcome a block to flowering and thus acquire competence to flower in the following spring after experiencing prolonged cold exposure or winter cold. The vernalization pathways in different angiosperm lineages appear to have convergently evolved to adapt to temperate climates. Molecular and epigenetic mechanisms for vernalization regulation have been well studied in the crucifer model plant Arabidopsis thaliana.Here, we review recent progresses on the vernalization pathway in Arabidopsis. In addition, we summarize current molecular and genetic understandings of vernalization regulation in temperate grasses including wheat and Brachypodium, two monocots from Pooideae, followed by a brief discussion on divergence of the vernalization pathways between Brassicaceae and Pooideae. | Xiao Luo Yuehui He | 2020 | Journal of Integrative Plant Biology2020，62，1： | 11 |
| 9 | Nitrogen deposition and reduction of terrestrial biodiversity:Evidence from temperate grasslands显示文摘Biodiversity is thought to be essential for ecosystem stability, function and long-term sustainability. Since nitrogen is the limiting nutrient for plant growth in many terrestrial ecosystems, reactive nitrogen has the potential to reduce the diversity of terrestrial vegetation and associated biota through favouring species adapted to quickly exploiting available nutrients. Although the potential has long been recognised, only recently has enough evidence come together to show beyond reasonable doubt that these changes are already occurring. Linked together, experimental, regional/e.rnpirical, and time-series research provide a powerful argument that enhanced deposition of reactive nitrogen across Great Britain, and potentially the rest of Europe, has resulted in a significant and ongoing decline in grassland species richness and diversity. | Nancy B.Dise Carly J.Stevens | 2005 | Science China(Life Sciences)2005，48，z2： | 8 |
| 10 | Abiotic and biotic drivers of species diversity in understory layers of cold temperate coniferous forests in North China显示文摘Understory plants are important components of forest ecosystems and play a crucial role in regulating community structures,function realization,and community succession.However,little is known about how abiotic and biotic drivers affect the diversity of understory species in cold temperate coniferous forests in the semiarid climate region of North China.We hypothesized that(1)topographic factors are important environmental factors affecting the distribution and variation of understory strata,and(2)different understory strata respond differently to environmental factors;shrubs may be significantly affected by the overstory stratum,and herbs may be more affected by surface soil conditions.To test these hypotheses,we used the boosted regression tree method to analyze abiotic and biotic environmental factors that influence understory species diversity,using data from 280 subplots across 56 sites in cold temperate coniferous forests of North China.Elevation and slope aspect were the dominant and indirect abiotic drivers affecting understory species diversity,and individual tree size inequality(DBH variation)was the dominant biotic driver of understory species diversity;soil water content was the main edaphic factors affecting herb layers.Elevation,slope aspect,and DBH variation accounted for 36.4,14.5,and 12.1%,respectively,of shrub stratum diversity.Shrub diversity decreased with elevation within the range of altitude of this study,but increased with DBH variation;shrub diversity was highest on north-oriented slopes.The strongest factor affecting herb stratum species diversity was slope aspect,accounting for 25.9%of the diversity,followed by elevation(15.7%),slope(12.2%),and soil water content(10.3%).The highest herb diversity was found on southeast-oriented slopes and the lowest on northeast-oriented slopes;herb diversity decreased with elevation and soil water content,but increased with slope.The results of the study provide a reference for scientific management and biodiversity protection in cold temperate coniferous forests of North China. | Hui Wang Mengtao Zhang Hongwei Nan | 2019 | Journal of Forestry Research2019，30，6： | 5 |
| 11 | Carbon,nitrogen and phosphorus stoichiometry in Pinus tabulaeformis forest ecosystems in warm temperate Shanxi Province,north China显示文摘Although carbon(C), nitrogen(N), and phosphorous(P) stoichiometric ratios are considered good indicators of nutrient excess/limitation and thus of ecosystem health, few reports have discussed the trends and the reciprocal effects of C:N:P stoichiometry in plant–litter–soil systems. The present study analyzed C:N:P ratios in four age groups of Chinese pine, Pinus tabulaeformis Carr., forests in Shanxi Province, China: plantation young forests(AY,<20 year-old); plantation middle-aged forests(AM, 21–30 year-old); natural young forests(NY,<30 year-old); and natural middle-aged forests(NM,31–50 year-old). The average C:N:P ratios calculated for tree, shrub, and herbaceous leaves, litter, and soil(0–100 cm) were generally higher in NY followed by NM,AM, and AY. C:N and C:P ratios were higher in litter than in leaves and soils, and reached higher values in the litter and leaves of young forests than in middle-aged forests;however, C:N and C:P ratios were higher in soils of middle-aged forests than in young forests. N:P ratios were higher in leaves than in litter and soils regardless of stand age; the consistent N:P<14 values found in all forests indicated N limitations. With plant leaves, C:P ratios were highest in trees, followed by herbs and shrubs, indicating a higher efficiency in tree leaf formation. C:N ratios decreased with increasing soil depth, whereas there was no trend for C:P and N:P ratios. C:N:P stoichiometry of forest foliage did not exhibit a consistent variation according to stand age. Research on the relationships between N:P, and P, N nutrient limits and the characteristics of vegetation nutrient adaptation need to be continued. | Ning Wang Fengzhen Fu Baitian Wang Ruijun Wang | 2018 | Journal of Forestry Research2018，29，6： | 4 |
| 12 | Land cover changes and fragmentation in mountain neotropical ecosystems of Oaxaca, Mexico under community forest management显示文摘Changes in land cover have a direct impact on forest ecosystem goods and services. In this study, changes in land cover in Sierra de Juarez–Oaxaca ecosystems were estimated using a consistent processing of Landsat images and OBIA methodology. Additionally, landscape analyses using FRAGSTAT were conducted. In 2014, Sierra de Juarez–Oaxaca was covered by approximately 84% of forests, mainly pine-oak and cloud forests. After extensive deforestation until 2001, this trend was reversed and the forest cover surface area in 2014 was slightly higher than in 1979. The comparison of the landscape structure of the forested and agricultural lands suggests an increase in habitat heterogeneity. However, interspersion and juxtaposition indices, showing the patch shape by patch area and perimeter, were similar throughout the study period(1979–2014). Social and economic drivers can explain this situation: namely, community organization, forest enterprises, payment for ecosystem services programs, and changes of agricultural activity. Communities in the Sierra of Oaxaca have reforested degraded lands, created community forest enterprises, and preserved the forest under conservation schemes like those proposed by the Mexican payment for ecosystem services programs. However, their sustainable management faces internal challenges and has become highly dependent on political and institutional decisions beyond their control. | Rafael M~a Navarro Cerrillo Dennis J.Esteves Vieira Susana Ochoa-Gaona Bernardus H.J.de Jong M~a del Mar Delgado Serrano | 2019 | Journal of Forestry Research2019，30，1： | 4 |
| 13 | Effects of six years of simulated N deposition on gross soil N transformation rates in an old-growth temperate forest显示文摘Elevated atmospheric nitrogen(N) deposition has been detected in many regions of China, but its effects on soil N transformation in temperate forest ecosystems are not well known. We therefore simulated N deposition with four levels of N addition rate(N0, N30, N60, and N120) for6 years in an old-growth temperate forest in Xiaoxing'an Mountains in Northeastern China. We measured gross N transformation rates in the laboratory using ^(15)N tracing technology to explore the effects of N deposition on soil gross N transformations taking advantage of N deposition soils. No significant differences in gross soil N transformation rates were observed after 6 years of N deposition with various levels of N addition rate. For all N deposition soils, the gross NH_4^+ immobilization rates were consistently lower than the gross N mineralization rates,leading to net N mineralization. Nitrate(NO_3^-) was primarily produced via oxidation of NH_4^+(i.e., autotrophic nitrification), whereas oxidation of organic N(i.e., heterotrophic nitrification) was negligible. Differences between the quantity of ammonia-oxidizing bacteria and ammonia-oxidizing archaea were not significant for any treatment, which likely explains the lack of a significant effect on gross nitrification rates. Gross nitrification rates were much higher than the total NO_3^- consumption rates,resulting in a build-up of NO_3^-, which highlights the high risk of N losses via NO_3^- leaching or gaseous N emissions from soils. This response is opposite that of typical N-limited temperate forests suffering from N deposition,suggesting that the investigated old-growth temperate forest ecosystem is likely to approach N saturation. | Peng Tian Jinbo Zhang Christoph Müller Zucong Cai Guangze Jin | 2018 | Journal of Forestry Research2018，29，3： | 3 |
| 14 | Study of Yield Combining Ability and Genetic Relationship Among Exotic Tropical,Subtropical Maize(Zea mays L.) Inbreds and Temperate Maize Inbreds in China显示文摘Information on the genetic relationship between tropical maize (Zea mays L), germplasm and temperate maize germplasm is of great value to maize breeding. The objective of this study was to determine the combining ability and genetic relationship of 25 inbreds extracted from five tropical maize populations and a land race, with four temperate maize inbreds (Huangzaosi, Mo17, B73 and Dan 340). The 25 tropical inbreds were crossed with the four temperate inbreds and evaluated. Lines from Suwan1 and POP28 had high general combining ability (GCA) for grain yield. The lines from POP32 (ETO) had the highest special combining ability (SCA) with B73; the average SCA value of the 5 lines was 879 kg/ha. The lines from Suwan1had the second-highest SCA (584 kg/ha) with Huangzaosi. The lines from Suwan1 had the greatest relative heterosis (20%) with B73, followed by the lines from POP32 (ETO) with B73 (19%). Five heterotic patterns have been identified from this study: Suwan1 × Reid, ETO × Reid, POP28 × Reid, POP28 × Ludahonggu, and Suwan1 × Lancaster. | FAN Xing-ming, TAN Jing, YANG Jun-yun, LIU Feng, HUANG Bi-hua and HUANG Yun-xiao( Yunnan Academy of Agricultural Sciences , Kunming 650205 , P. R . China Baoshan Institute of Agricultural Sciences , Baoshan 678000 , P.R. China Dehong Institute of Agricultural Sciences , Luxi 678400 , P.R. China) | 2002 | Agricultural Sciences in China2002，1，7： | 2 |
| 15 | STUDIES ON THE ENVIRONMENT STRUCTURE OF NATURAL NIDI AND EPIDEMIC AREAS OF HEMORRHAGIC FEVER WITH RENAL SYNDROME IN CHINA显示文摘The environment structure of natural nidi and epidemic areas of hemorrhagic fever with renal syndrome (HFRS) possesses characteristics of topography, hydrology, climate, soil, vegetation, and animals. The natural nidi and epidemic areas of HFRS are distributed mainly in plain and hilly regions under 500 meters above the sea level; in plentiful-water zones and transitional zones; in temperate zone and subtropical zone of the eastern monsoon region; in the abundant-ainminum soil region and the sial soil region; in the eastern China damp forest region (agricultural districts and northeast forest districts); in the eastern Asia dampness-prefering animal geographic region. Apodemus agrarius and Rattus norvegicus are the thriving animal population, predominant species or common species as well as the main reservoir hosts and sources of infection in the natural nidi and epidemic areas of HFRS. | 陈化新 丘福禧 | 1994 | Chinese Medical Journal1994，，2： | 2 |
| 16 | Protein phosphorylation associated with drought priming-enhanced heat tolerance in a temperate grass species显示文摘Protein phosphorylation is known to play crucial roles in plant tolerance to individual stresses,but how protein phosphorylation is associated with cross-stress tolerance,particularly drought priming-enhanced heat tolerance is largely unknown.The objectives of the present study were to identify phosphorylated proteins and phosphorylation sites that were responsive to drought priming and to determine whether drought priming-enhanced heat tolerance in temperate grass species involves changes in protein phosphorylation.Comparative analysis of phosphoproteomic profiles was performed on leaves of tall fescue(Festuca arundinacea)exposed to heat stress(38/33°C,day/night)with or without drought priming.A total of 569 differentially regulated phosphoproteins(DRPs)with 1098 phosphorylation sites were identified in response to drought priming or heat stress individually or sequentially.Most DRPs were nuclear-localized and cytosolic proteins.Motif analysis detected[GS],[DSD],and[S..E]as major phosphorylation sites in casein kinase-II and mitogen-activated protein kinases regulated by drought priming and heat stress.Functional annotation and gene ontology analysis demonstrated that DRPs in response to drought priming and in droughtprimed plants subsequently exposed to heat stress were mostly enriched in four major biological processes,including RNA splicing,transcription control,stress protection/defense,and stress perception/signaling.These results suggest the involvement of post-translational regulation of the aforementioned biological processes and signaling pathways in drought priming memory and cross-tolerance with heat stress in a temperate grass species. | Xiaxiang Zhang Lili Zhuang Yu Liu Zhimin Yang Bingru Huang | 2020 | Horticulture Research2020，7，1： | 2 |
| 17 | Functional integrity of freshwater forested wetlands,hydrologic alteration,and climate change显示文摘Climate change will challenge managers to balance the freshwater needs of humans and wet-lands.The Intergovernmental Panel on Climate Change predicts that most regions of the world will be exposed to higher temperatures,CO2,and more erratic precipitation,with some regions likely to have alternating episodes of intense flooding and mega-drought.Coastal areas will be exposed to more fre-quent saltwater inundation as sea levels rise.Local land managers desperately need intra-regional climate information for site-specific planning,management,and restoration activities.Managers will be chal-lenged to deliver freshwater to floodplains during climate change-induced drought,particularly within hydrologically altered and developed landscapes.Assessment of forest health,both by field and remote sensing techniques,will be essential to signal the need for hydrologic remediation.Studies of the util-ity of the release of freshwater to remediate stressed forested floodplains along the Murray and Mis-sissippi Rivers suggest that brief episodes of freshwater remediation for trees can have positive health benefits for these forests.The challenges of climate change in forests of the developing world will be considered using the Tonle Sap of Cambodia as an example.With little ecological knowledge of the im-pacts,managing climate change will add to environmental problems already faced in the developing world with new river engineering projects.These emerging approaches to remediate stressed trees will be of utmost importance for managing worldwide floodplain forests with predicted climate changes. | Beth A.Middleton Nicholas J.Souter | 2016 | Ecosystem Health and Sustainability2016，2，1： | 2 |
| 18 | Reconstruction of debris-flow activity in a temperate mountain forest catchment of central Mexico显示文摘The use of dendrochronology to study and date geomorphic processes in volcanic environments is still incipient, even more so on the volcanic slopes covered by temperate forests in central Mexico. Mass movements, such as debris flows, often impact forest stands where they cause damage to individual trees, thereby generating growth disturbances(GD) in the tree-ring records. The identification and dating of GD enables reconstruction of the age of trees colonizing bare surfaces after major events, but also allows the assessment of the frequency or spatial distribution of past geomorphic process activity. Here we used increment cores from 65 Pinus leiophylla, Abies religiosa, and Alnus jorullensis trees growing in the Axal gorge, on the southern slopes of La Malinche volcano, to unravel past debris-flow activity both temporally and spatially. Based on the combination of GD records, a weighted tree response index(Wit), field evidence and hydrometeorological records, we reconstructed 23 debris flows since 1933.Interestingly, almost two-thirds of the reconstructed years with debris-flow activity in Axal gorge match with events recorded in Axaltzintle gorge located on the NE slopes of La Malinche. These findings suggest a regional triggering mechanism, most likely related to the occurrence of hurricanes. This research could be useful for disaster risk management of the La Malinche National Park. | Osvaldo FRANCO-RAMOS Markus STOFFEL Juan Antonio BALLESTEROS-CANOVAS | 2019 | Journal of Mountain Science2019，16，9： | 2 |
| 19 | A molecular framework for seasonal growth-dormancy regulation in perennial plants显示文摘The timing of the onset and release of dormancy impacts the survival,productivity and spatial distribution of temperate horticultural and forestry perennials and is mediated by at least three main regulatory programs involving signal perception and processing by phytochromes(PHYs)and PHY-interacting transcription factors(PIFs).PIF4 functions as a key regulator of plant growth in response to both external and internal signals.In poplar,the expression of PIF4 and PIF3-LIKE1 is upregulated in response to short days,while PHYA and PHYB are not regulated at the transcriptional level.Integration of light and environmental signals is achieved by gating the expression and transcriptional activity of PIF4.During this annual cycle,auxin promotes the degradation of Aux/IAA transcriptional repressors through the SKP–Cullin-F–boxTIR1 complex,relieving the repression of auxin-responsive genes by allowing auxin response factors(ARFs)to activate the transcription of auxin-responsive genes involved in growth responses.Analyses of transcriptome changes during dormancy transitions have identified MADS-box transcription factors associated with endodormancy induction.Previous studies show that poplar dormancy-associated MADS-box(DAM)genes PtMADS7 and PtMADS21 are differentially regulated during the growth-dormancy cycle.Endodormancy may be regulated by internal factors,which are specifically localized in buds.PtMADS7/PtMADS21 may function as an internal regulator in poplar.The control of flowering time shares certain regulatory hierarchies with control of the dormancy/growth cycle.However,the particularities of different stages of the dormancy/growth cycle warrant comprehensive approaches to identify the causative genes for the entire cycle.A growing body of knowledge also indicates epigenetic regulation plays a role in these processes in perennial horticultural and forestry plants.The increased knowledge contributes to better understanding of the dormancy process and consequently to precise manipulation of dormancy-related horticultural traits,such as flowering time. | Donghwan Shim Jae-Heung Ko Won-Chan Kim Qijun Wang Daniel E Keathley Kyung-Hwan Han | 2014 | Horticulture Research2014，1，1： | 2 |
| 20 | Distribution features of stable oxygen isotopes in the typical monsoon temperate-glacier region, Mountain Yulong in China显示文摘During the summers of 1999 and 2000, sampling was carried out in Mt. Yulong, for the investigation of the spatial distribution of oxygen stable isotope in the atmospheric glacial hydro system and similar results obtained in the two years have confirmed our conclusion. There is an evident negative correlation between stable isotopic composition and air temperature precipitation amount, suggesting that there exits a strong 'precipitation amount effect' in this typical monsoon temperate glacier region. There are marked differences between the δ 18 O values in winter accumulated snow, glacial meltwater, summer precipitation and glacier feeding stream. Under the control of varied climatic conditions, spatial and temporal variations of above glacial hydro mediums are apparent. Isotopic depletion or fractionation and ionic changes had occurred during the phase change and transformation processes of snow ice, ice meltwater, flowing of runoff and contact with bedrock. The variation of stable isotope in a runoff can reflect not only its own flowing process but also its different feeding sources. | 何元庆 姚檀栋 康建成 杨梅学 沈永平 孙维贞 | 2001 | Chinese Journal of Polar Science2001，12，1： | 1 |
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