高效利用土壤磷素的植物营养学研究

论述磷在农业及生态系统中的重要地位,磷资源的危机以及磷土壤中的理化特性,探讨土壤的供磷潜力,不同植物品种以及相同品种不同基因型对土壤潜在磷资源的吸收利用差异,营养机制,遗传特性及其利用不同作物的基因型来活化,吸收利用土壤难溶态磷的可行性对策,从而为充分发挥植物自身潜力,提高土壤难溶态磷的生物有效性,高效利用土壤潜在磷资源,加快土壤磷素有效循环,节省资源,保护环境,真正达到生态系统的稳定与现代化农业     

福建泉州湾西部晚全新世孢粉组合特征及其古环境意义

通过对泉州湾西部QZDSZK02孔的沉积孢粉及AMS14 C进行分析,对泉州地区晚全新世古植被和古环境演化历史进行了恢复。其中,共鉴定出60种孢粉类型,主要以木本植物花粉和蕨类孢子为主,含草本植物花粉。根据孢粉特征及测年结果,划分出了4个孢粉组合带,恢复了本区植被演化和气候波动的4个阶段。探讨了孢粉来源,通过研究松属与温度的关系,得出泉州地区松属树种的兴衰与温度关系比较密切的结论。泉州湾晚全新世的海侵,可能是沉积物供给的减少或沿海地区构造的下降,不一定是海面上升的结果。     

科尔沁沙地麦里地区晚全新世植被演化

根据一个泥炭剖面高分辨率花粉资料序列,初步重建了科尔沁沙地麦里地区晚全新世的植被演化过程。在3100 a BP以前,该地以固定沙丘上生长的蒙古栎(Quercus mongolica Fisch.)等阔叶疏林为主;以后随着半固定沙丘和流动沙丘增多,蒿属(Artemisia L.)和藜科等草本植物逐渐增加,而固定沙丘上的阔叶树则趋于减少。在1000～660 a BP期间,麦里地区几乎所有沙丘植物都经历了繁盛生长,蒙古栎种群的扩大尤其显著。3100 a BP以来植被和沙丘的演化可能同人类活动影响有直接关系,而1000～660 a BP期间的植物繁盛则由生长季雨量增加引起。花粉统计分析还表明,在森林草原等生态过渡带,花粉浓度和花粉沉积率比花粉百分比更好地指示了植被演化过程。     

青藏高原东部地区晚新生代孢粉组合特征及其古地理意义

青藏高原东部晚新生代孢子花粉组合大致可分为三个组合两个亚组合。中新世组合主要以壳斗科,桦科以及榆科为主,并有大量的松科花粉。上新世以后组合则以壳斗科和松科花粉据优势,并有很多草本植物花粉。晚新生代孢粉植物群在本地区已经分出南北两个区系,反映了不同的气候特征或者不同的高度。青藏高原东部的孢粉资料显示本地区至少有两个成煤时期：中新世和上新世到早更新世。孢粉资料说明在中新世时青藏高原可能已经达到两千米高度。这个高度已经可以构成影响本地区气候特征的因素之一。青藏高原在晚新生代的抬升是我国季风气候和现代气候分区形成的一个很重要的因素。     

唐古拉山地区渐新世孢粉植物群及其古植被、古气候

唐古拉山地区广泛出露早新生代陆相地层,较好地记录了青藏高原北部新生代地质构造演化与古环境变迁的过程.通过在该区1:25万地质调查对雅西措组上段进行孢粉分析表明,孢粉组合以裸子植物花粉为主要成分,地质时代为早-中渐新世.在此基础上划分了3个孢粉植物群-气候期,当时植被是以松科植物为主组成的针叶林植被,从早期到中期喜湿热的蕨类植物和落叶阔叶树种增多;气候从凉爽湿润的南温带→半湿润偏干的北亚热带→偏干的南温带的转变.     

四川宣汉晚三叠世孢粉组合及其古植被与古气候意义

对四川盆地东北缘宣汉七里峡剖面须家河组进行了详细的孢粉学研究,发现丰富的孢粉化石,共计59属113种,其中包括蕨类植物孢子35属62种,裸子植物花粉22属47种,苔藓类植物孢子1属3种,以及藻类化石1属1种。据此建立一个孢粉组合,命名为Dictyophyllidites-Lunzisporites-Chasmatosporites组合(简称DLC组合),并进一步分为上、下两个亚组合。根据孢粉组合内一些重要分子的地质时代延限及与国内外有关孢粉组合的对比,提出其地质时代属于晚三叠世诺利期—瑞替期(Norian—Rhaetian)。该孢粉植物群反映了一个以蕨类植物的真蕨类、石松类和裸子植物的松柏类和苏铁类群等占主导且较为繁盛的植被面貌,揭示出温暖潮湿的亚热带—热带气候环境。     

宁晋泊晚更新世孢粉组合及其古环境演变

宁晋泊是河北平原南部三大古湖群之一,通过LN42．5m厚沉积剖面的孢粉分析,获得古植物群演替达近20次,反映古气候变化具明显冷暖气候旋回5次以上,其中有2次寒冷期,3次湿暖期。结合6．4m以上~(14)C年龄数据推断计算晚更新世与全新世界线在7．5m,这一界线与孢粉植物群、古气侯与古环境等分异界线非常吻合。因此作者推断宁晋泊的形成、发展与消亡时代相应在晚更新世早期的温暖期,全新世高温期再次复兴,后被河流沉积物所掩埋而消亡形成洼地。     

孢粉记录的晚全新世以来大兴安岭北部多年冻土泥炭地演化及其影响因素

当前泥炭所揭示的区域古植被、古气候与环境变化相关工作已广泛开展,然而对于泥炭地本身演化的研究却很少涉及,尤其是对于大兴安岭北部多年冻土泥炭地演化及其影响因素仍不清晰,阻碍了人们对这一特殊类型泥炭地历史动态和未来发展趋势的认知。为此基于大兴安岭北部多年冻土泥炭岩芯孢粉证据,利用AMS¹⁴C测年技术,重建了区域3500 cal a BP以来植被与气候历史,并与其他古气候指标进行对比,从而揭示区域泥炭地演化及其影响因素。结果表明:3500-2900 cal a BP植被以松属、喜暖乔木及水龙骨科为主,气候温暖湿润成为泥炭孕育期;2900-2250 cal a BP植被以松属、喜暖乔木及蒿属为主,气候温暖潮湿成为泥炭发育启动期;2250-1650 cal a BP植被以松属、桦属及水龙骨科为主,气候寒冷湿润成为泥炭发育旺盛期;1650-1150 cal a BP植被以松属和蒿属为主,气候寒冷干燥成为泥炭发育减缓和停滞期;1150-750 cal a BP 阔叶林和湿地植被扩张,气候温暖湿润成为泥炭发育再次启动期,完成由富营养沼泽到中营养沼泽类型的转变;750 cal a BP至今植被以松属、桤木属及莎草科为主,气候寒冷湿润成为泥炭发育再次旺盛期,中营养沼泽开始向贫营养沼泽类型过渡。造成多年冻土泥炭地演化的主导因素并不是地质地貌变动和人类活动,而是来自气候变化及其驱动下多年冻土环境的改变,因此气候变化才是影响多年冻土泥炭地演化的主动力,未来多年冻土泥炭地变化取决于全球气候的发展。     

西格陵兰中晚全新世硅藻组合及其古环境演变

对西格陵兰海域GA306-GC3孔中的89个样品进行鉴定,共发现46个属的107个硅藻种及其变种,运用聚类分析方法后发现该孔可分为3个硅藻带和2个亚带。硅藻丰度变化与格陵兰冰芯重建的6 700年以来的温度变化具有明显一致性,同时也与其它古气候记录有较好的对应关系,共同追溯了西格陵兰海域6 700年来的气候变化,记录了全新世大暖期、黑暗时代冷期、中世纪暖期和小冰期等古气候事件。     

印度库茂恩喜马拉雅纳尼塔尔温带地区晚全新世古植被和古气候

根据从印度库茂恩（Kumaun)喜马拉雅纳尼塔尔（Naini Tal)温带地区获得的85cm钻井的孢粉资料,恢复了1720＋／－130年以来晚全新世古植被演变史,并推测了当地的古气候,当前孢粉资料说明了该地区当时发育有栎树混交林和波动的温暖润气候,孢粉组合序列的初始阶段,森林距沉积盆地较远,但是,由于气候变得更加温暖潮湿,森林也很快茂密起来,约1200年前,因气候恶化,森林变得稀疏,而在约124年前,气候再次转好,麦类及其他作物花粉资料证明农耕活动大约开始于1460年前左右。     

Late holocene environments in Las Tablas de Daimiel (south central Iberian peninsula,Spain)

The use of a high resolution pollen record in combination with geochemical data from sediments composed mainly of layers of charophytes alternating with layers of vegetal remains plus some detrital beds permits the reconstruction of the environmental evolution of the last 3000 years in an inland wetland of the Mediterranean domain, thus introducing a new climatic dataset for the Late Holocene. Hydrological fluctuations, reflected in the relationship between emerged and aquatic vegetation and inorganic and organic C and N changes, can be related to aridity or humid phases, while relations among arboreal taxa (Quercus and Pinus) and Artemisia are used as temperature indicators. Five climatic periods have been identified: a Subatlantic Cold Period (<150 b.c.), cold and arid; the Roman Warm Period (150 b.c.–a.d. 270), warmer and wetter; the Dark Ages (a.d. 270–a.d. 950), colder and drier; the Medieval Warm Period (a.d. 950–a.d. 1400), warmer and wetter; and the Little Ice Age (>a.d. 1400) indicated by a cooling and drying trend. Despite the lack of any direct evidence of human action, there are some episodes related to deforestation during the Reconquista (Middle Ages) that mask the real climatic signal.     

长白山高山冻原生态系统的碳储量

对长白山高山冻原生态系统碳在植被-凋落物-土壤中的分布进行了研究。结果表明,在长白山高山冻原植被亚系统中,碳储量分布规律是典型高山冻原(TT)>石质高山冻原(ST)>草甸高山冻原(MT)>沼泽高山冻原(WT)>石海高山冻原(RT),长白山高山冻原的植被碳储量为3.3457×104t。而生物量分布规律是WT>TT>MT>ST>RT。在长白山高山冻原凋落物亚系统中,平均凋落物量是0.991 kg.hm-2.年-1;凋落物碳储量为1.5043×104t,碳储量分布规律是TT>ST>MT>RT>WT。长白山高山冻原土壤(0~20 cm)亚系统中,有机碳储量为3.162×105t;每年约有1.4105×104t碳通过土壤呼吸释放到大气圈,长白山高山冻原植被-土壤系统现已成为3.6471×105t碳储库。     

Elevational gradients during the Late-Glacial/Holocene vegetational transition in southern Bulgaria

The Late Glacial and early-Holocene vegetational history of a newly dated pollen and macrofossil diagram from Besbog, a cirque lake at 2250 m just above the forest limit in the Pirin Mountains of southwestern Bulgaria, is compared with a newly dated pollen diagram for the mire Shiroka Polyana at 1400 m in the conifer forest of the nearby Rhodope Mountains in order to investigate the chronology of major changes in the vegetation at different elevations. In the Lake Besbog record the non-arboreal pollen assemblage of the Late Glacial changed abruptly to that of Betula, Quercus and other deciduous types. The date for this change is about 11.6 ka cal b.p. The Quercus assemblage may be composed of pollen blown from intermediate elevations, to which deciduous forest had expanded because of higher summer temperatures related to high summer insolation. At Shiroka Polyana (1400 m) in the modern conifer belt, a similar change did not occur until about 8.8 ka cal b.p. The persistence of the dry steppe or steppe forest in the early Holocene at this lower site can also be attributed to high summer insolation. Thus as atmospheric temperature increased at the end of the Late Glacial, deciduous forests expanded first at intermediate elevations in the Pirin Mountains and only later in the Rhodope Mountains at lower elevations as summer insolation decreased.     

长白山高山冻原植被生物量的分布规律

从物种生物量、优势种器官生物量和植被生物量角度,探讨了长白山高山冻原生态系统生物量的空间变化规律．结果表明,在调查的43种长白山高山冻原植物中,单物种生物量排序前5种植物分别是牛皮杜鹃(Rhododendron chrysanthum)(159．01kg·hm^-2)、笃斯越桔(Vaccinium jiliginosum var．alpinum)(137．52kg·hm^-2)、高山笃斯(Vaccinium uliginosum)(134．7kg·hm^-2)、宽叶仙女木(Dryas octopetala var．asiatica)(131．5kg·hm^-2)圆叶柳(Salix rotundifolia)(128．4kg·hm^-2)．它们是长白山高山冻原生态系统的优势种．地下与地上生物量和地下与总生物量之比随海拔升高逐渐增加．植被生物量随海拔升高。总体呈逐渐减小的趋势。植被生物量与海拔高度呈显著负相关．长白山高山冻原生态系统平均生物量为2．21t·hm^-2,对调节长白山小气候、涵养水源、水土保持等生态服务功能的发挥有着重要的作用。同时对固定大气CO2起着汇的作用。     

Lake–peat bog transformation recorded in the sediments of the Stare Biele mire (Northeastern Poland)

The history of Stare Biele paleolake (northeast Poland) has been reconstructed using subfossil Cladocera remains and pollen and spores of aquatic and mire plants from a sediment core. Sediment accumulation began approximately 12,000 years ago during the Older Dryas chronozone. Throughout the entire Late Glacial period, the basin was a small, low-trophic state lake with a developed open-water zone. A well-recorded increase in the trophic state started at the beginning of Holocene. The lake reached its highest trophic level during the early and middle Atlantic chronozone. The first human activity in the lake catchment area occurred at this time, as recorded by fern spores and numerous charcoal grains. Repeated rises in lake water level are documented at the beginning and throughout the early part of the Younger Dryas. Two clear events of decreasing lake water levels are recorded, first during the middle part of the Younger Dryas and second in the Preboreal. Terrestrialization processes first intensified at the end of Atlantic period, which appears to correspond to a decrease in pH. Guest editors: K. Buczkó, J. Korponai, J. Padisák & S. W. Starratt Palaeolimnological Proxies as Tools of Environmental Reconstruction in Fresh Water     

Vegetation changes and human occupation in the Patagonian steppe, Argentina, during the late Holocene

Vegetation changes during the late Holocene are interpreted from four fossil pollen sequences from two caves at the Los Toldos archaeological locality, Santa Cruz province, Argentina. Taphonomic processes are particularly taken into account in order to analyze the effects on the fossil pollen records of biotic factors such as human occupation and animals, and abiotic ones such as volcanic ash fall. Fossil pollen assemblages are interpreted using local modern pollen data. The main vegetation change occurred at ca. 3750 uncal b.p., when a shrub steppe of Asteraceae subf. Asteroideae with Schinus, Ephedra frustillata and a high proportion of grasses was replaced by a shrub steppe of Colliguaja integerrima and Asteraceae subf. Asteroideae. This change is synchronous with an archaeological record change and could be related either to moderate climatic variations or the effects of ash fall on the environment. Plant communities similar to the present-day ones were established in the Los Toldos area from ca. 3750 uncal b.p.     

Late Pleistocene and Holocene pollen stratigraphy at Lago di Vico, central Italy

A new pollen record from Lago di Vico (core V1) provides fundamental new information towards reconstruction of flora and vegetation history in central Italy during the last 90 000 years. The chronological framework is secured by seventeen AMS¹⁴C dates, one⁴⁰Ar/³⁹Ar date and tephra analyses. At the base of the pollen record, i.e. shortly after the⁴⁰Ar/³⁹Ar date 87 000±7000 B.P., three phases with significant expansion of trees are recorded in close succession. These forest phases, which stratigraphically correspond to St Germain II (and Ognon?) and precede pleniglacial steppe vegetation, are designated by the local names Etruria I, Etruria II and Etruria III. During the pleniglacial, a number of fluctuations of angiosperm mesophilous trees suggest the presence of tree refugia in the area. The lowest pollen concentration values are recorded at ca. 22 000 B.P. which corresponds with other pollen records from the region. The late-glacial is characterized by an expansion in the arboreal pollen curves that is less pronounced, however, than in other pollen profiles from Italy. The Holocene part of the profile is consistently dominated by deciduous oak pollen. No major changes in arboreal pollen composition are recorded but several marked and sudden declines of the tree pollen concentration suggest that the forest cover underwent dramatic changes. Clear evidence for human impact is recorded only when cultivated crops became important which dates to ca. 2630±95 B.P.