Dendroclimatic response of Picea jezoensis along an altitudinal gradient in Changbai Mountains

We investigated the effects of climate on Yeddo spruce (Picea jezoensis) radial growth along altitudinal gradients in the subalpine forests of Changbai Mountains using dendroclimatic analyses. Yeddo spruce at its lower and upper distribution limits was more sensitive to the climate. Despite precipitation being generally considered sufficient, we found that precipitation significantly affected Yeddo spruce radial growth. Yeddo spruce at its lower distribution limit was much more affected by precipitation while Yeddo spruce at its upper distribution limit was much more affected by minimum temperature. Yeddo spruce at its medial altitude was affected by sunshine ratio. These results demonstrated that climate affected Yeddo spruce growth differently depending on its altitudinal distributions in the Changbai Mountains. Both temperature and precipitation in the annu-alization period significantly correlated with Yeddo spruce radial growth. However, warmer signals were not reflected in radial growth trend during the past 20 years because annual total precipitation declined during the same period. It appeared that the climate affected tree rings growth by altering soil moisture availability.     

GIS-based analysis of forest degradations in Baihe Forestry Bureau, northeast China

Forests in the Changbai Mountains are important timber sources for economic development of the society and provide ecological services in northeast China. In order to strengthen forest resource management, this paper analyzed management-induced changes in forest structure, tree species composition and forest landscape pattern from 1987 to 2000 for Baihe Forestry Bureau in Jilin Province based on digitized forest parcel maps and forest survey data. The results suggested that the area of Mature, High-Stocking, and Close-Canopy Forests decreased by 31.4%, 55.9% and 10.7% respectively; volume of Mixed Forest, the native forest vegetation type, decreased by 17.8%; the number of patches increased tremendously but the mean patch density decreased sharply for Mature, High-Stocking, Close-Canopy, and Mixed Forests. All the changes in forest structure, species composition, and landscape pattern indicated severe degradations going on with the forests in Baihe Forestry Bureau. Because of the effect of degradation to forest services, restoring forest resources and protecting biodiversity has become urgently important. The strategies of sustainable forest management need to be worked out and implemented.     

冰雪产业推动“两山”理论发展的“吉林样本”

“冰天雪地也是金山银山”的“两山”理论,是习近平生态文明思想的重要组成部分,以探讨冰雪产业如何推动“两山”理论发展为切入点,运用文献资料、逻辑辩证、田野调查等方法,明晰了“冰天雪地也是金山银山”的“两山”理论内涵,总结、凝练并还原了吉林省在冰雪产业方面推动“两山”理论建设的具体路径,为寒地区域充分利用冰雪资源优势发展冰雪经济提供了“案例样本”与“根本遵循”。     

西秦岭温泉岩体岩石地球化学与含矿性分析

温泉钼矿是至今为止在西秦岭造山带上所发现的最大的一个斑岩型钼矿床,钼矿床产于温泉复式花岗岩体内部,钼矿化主要与陈家大湾细粒二长花岗斑岩和岩体裂隙有关。通过对温泉岩体不同期次侵入体中的钼元素含量统计,发现钼元素含量矿区范围内的岩体中高于外围,细粒二长花岗斑岩中的钼元素含量高于早阶段两次侵入的岩体,认为温泉钼矿床的钼元素主要来自于细粒二长花岗斑岩。通过对三次侵入的岩体地球化学特征与国内典型的斑岩型矿床地球化学特征的对比研究,认为温泉钼矿为斑岩型钼矿床,具斑岩钼成矿专属性。     

太行山典型小流域潜流动态变化研究

为了科学地对太行山区地下水环境进行综合评价，本试验采用了“翻斗式”自计量水技术，对该区普遍存在的裂隙潜流的动态变化过程进行新监测.根据监测的数据分析了该区潜流的日动态变化过程和水文年动态变化过程，分析结果说明造成这种动态变化的根本原因是太阳净辐射的变化，直接原因是植物的蒸散作用；同时，降雨对潜流的年内变化也有着直接的影响.     

宁夏贺兰山地区石炭纪沉积环境演化规律探讨

通过对石炭纪地层单元的岩石特征、沉积特征和层序结构分析,认为宁夏贺兰山地区石炭纪地层发育良好,层序连续,其岩石地层序列自下而上可划分为土坡组和太原组;岩石组合以陆源碎屑岩、泥质岩和碳酸盐岩沉积为主;贺兰山地区石炭系沉积相演化序列总体呈后退型浅水三角洲沉积层序;在晚石炭世到早二叠世,三角洲体系的沉积构成样式发生了明显变化,反映出早期受波浪作用较强、中期潮汐作用明显、晚期河流作用迅速增强的沉积演化规律.     

Climate change impacts on native cutthroat trout habitat in Colorado streams

Headwater streams support vital aquatic habitat yet are vulnerable to changing climate due to their high elevation and small size. Coldwater fish are especially sensitive to the altered streamflow and water temperature regimes during summer low flow periods. Though previous studies have provided insights on how changes in climate and alterations in stream discharge may affect habitat availability for various native cutthroat trout species, suitable physical habitats have not been evaluated under future climate projections for the threatened Greenback Cutthroat Trout (GBCT) native to headwater regions of Colorado, USA. Thus, this study used field data collected from selected headwater streams across the current distribution of GBCT to construct one-dimensional hydraulic models to evaluate streamflow and physical habitat under four future climate projections. Results illustrate reductions in both predicted streamflow and physical habitat for all future climate projections across study sites. The projected mean summer streamflow shows greater decline (−52% on average) compared to the projected decline in mean August flow (−21% on average). Moreover, sites located at a relative higher elevation with larger substrate and steeper slope were projected to experience more reductions in physical habitat due to streamflow reductions. Specifically, streams with step-pool morphologies may experience grater changes in available habitat compared to pool-riffle streams. Future climate change studies related to coldwater fish that examine spatial variation in flow alteration could provide novel data to complement the existing literature on the thermal characteristics. Tailoring reintroduction and management efforts for GBCT to the individual headwater stream with adequate on-site monitoring could provide a more holistic conservation approach.     

Estimating aboveground forest biomass from canopy reflectance model inversion in mountainous terrain

The amount and spatial distribution of aboveground forest biomass (AGB) are required inputs to forest carbon budgets and ecosystem productivity models. Satellite remote sensing offers distinct advantages for large area and multi-temporal applications, however, conventional empirical methods for estimating forest canopy structure and AGB can be difficult in areas of high relief and variable terrain. This paper introduces a new method for obtaining AGB from forest structure estimates using a physically-based canopy reflectance (CR) model inversion approach. A geometric-optical CR model was run in multiple forward mode (MFM) using SPOT-5 imagery to derive forest structure and biomass at Kananaskis, Alberta in the Canadian Rocky Mountains. The approach first estimates tree crown dimensions and stem density for satellite image pixels which are then related to tree biomass and AGB using a crown spheroid surface area approach. MFM estimates of AGB were evaluated for 36 deciduous (trembling aspen) and conifer (lodgepole pine) field validation sites and compared against spectral mixture analysis (SMA) and normalised difference vegetation index (NDVI) biomass predictions from atmospherically and topographically corrected (SCS+C) imagery. MFM provided the lowest error for all validation plots of 31.7 tonnes/hectare (t/ha) versus SMA (32.6 t/ha error) and NDVI (34.7 t/ha) as well as for conifer plots (MFM: 23.0 t/ha; SMA 27.9 t/ha; NDVI 29.7 t/ha) but had higher error than SMA and NDVI for deciduous plots (by 4.5 t/ha and 2.1 t/ha, respectively). The MFM approach was considerably more stable over the full range of biomass values (67 to 243 t/ha) measured in the field. Field plots with biomass > 1 standard deviation from the field mean (over 30% of plots) had biomass estimation errors of 37.9 t/ha using MFM compared with 65.5 t/ha and 67.5 t/ha error from SMA and NDVI, respectively. In addition to providing more accurate overall results and greater stability over the range of biomass values, the MFM approach also provides a suite of other biophysical structural outputs such as density, crown dimensions, LAI, height and sub-pixel scale fractions. Its explicit physical-basis and minimal ground data requirements are also more appropriate for larger area, multi-scene, multi-date applications with variable scene geometry and in high relief terrain. MFM thus warrants consideration for applications in mountainous and other, less complex terrain for purposes such as forest inventory updates, ecological modeling and terrestrial biomass and carbon monitoring studies.     

从城市环境特征中寻求城市绿地系统布局结构特点——安溪县城绿地系统规划

安溪县城绿地系统规划在自然环境特征与城市发展建设中以绿地进行糅和协调。在县域绿地系统规划中,以保护自然山水资源为主导,结合水源水质的保护布置绿地,不仅构筑了县域绿地系统结构特点,还对县域旅游事业的发展具有促进作用。在县城城市绿地系统规划布局中,结合城市排涝泄洪需要,将排涝泄洪设施以明沟渠的形式,两侧布置一定宽度的绿地带,不仅满足了城市居民休闲活动功能,还起到了景观视廊和显山露水的作用,形成了安溪县城独特的绿地系统构架,在城市特色形成中发挥了绿地的积极作用。     

阿尔泰山山前活动断裂带内现今地应力状态及稳定性分析

新疆阿尔泰地区分布着亚洲大陆内部一个规模宏大的活动构造带,同时,历史地震资料也显示阿尔泰山是一个比较活跃的地震带,分析断裂带内现今地应力状态对评价其地震活动的危险性具有重要意义。通过对布置在阿尔泰山山前活动断裂带内2个近700 m的深孔进行原位水压致裂法地应力测试,揭示了活动带内现今应力状态分布规律。结果表明:测试范围内空间主应力状态在埋深320 m左右由逆断型向走滑型转换,进而说明该复合断层近场存在应力分区现象;两孔实测最大水平主应力方位主要呈NW向,与震源机制解综合印证了区内NWW向断裂右旋走滑的活动特征。最后,基于实测地应力资料,结合库伦摩擦滑动准则及Byerlee定律对研究区内活动断裂的稳定性进行了力学分析,分析得出截至目前该活动断裂尚未具备诱发失稳的力学条件,处于相对稳定状态。这为其现今活动性研究补充了新的基础地质力学资料,为近场有关工程项目的选址提供科学参考。