Ying Yong Sheng Tai Xue Bao
August 2024
This study was conducted in Liupanshan Forest Ecological Positioning Station of the National Forestry and Grassland Administration. We monitored sap flow of plantation in the Xiangshui River sub-basin throughout the 2019 growing season (from May 17 to October 12), as well as the meteorological conditions and soil environment (soil temperature and soil water content), to analyze the comprehensive environmental responses of sap flow in under different weather conditions. The results showed that sap flow rate increased and then decreased on the daily scale, with the highest rate on sunny days, followed by overcast days and then rainy days.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
February 2023
To solve the problems of understory plant shortage and biodiversity reduction caused by high tree density of plantations on the Loess Plateau in northwest China, we analyzed the data collected by field survey and from literatures. We used the upper boundary line method to examine the impacts of canopy density on understory plant diversity. Based on field survey at the Guanshan Forest Farm of Jingchuan County of Gansu Pro-vince, the species number of understory plants in plantations was higher than that in natural grassland (91 vs.
View Article and Find Full Text PDFJ Environ Manage
March 2023
Payments for ecosystem services (PES) are becoming a global ecological protection strategy used to promote sustainable social and economic development. However, the current PES research and applications are often local and one-sided. The lack of a unified framework for PES results in a high policy cost and low ecological and social benefits.
View Article and Find Full Text PDFGlob Chang Biol
April 2022
Drylands cover more than 40% of Earth's land surface and occur at the margin of forest distributions due to the limited availability of water for tree growth. Recent elevated temperature and low precipitation have driven greater forest declines and pulses of tree mortality on dryland sites compared to humid sites, particularly in temperate Eurasia and North America. Afforestation of dryland areas has been widely implemented and is expected to increase in many drylands globally to enhance carbon sequestration and benefits to the human environment, but the interplay of sometimes conflicting afforestation outcomes has not been formally evaluated yet.
View Article and Find Full Text PDFHuman bodily kinesthetic sensing is generally complicated and ever-changing due to the diversity of body deformation as well as the complexity of mechanical stimulus, which is different from the unidirectional mechanical motion. So, there exists a huge challenge for current flexible sensors to accurately differentiate and identify what kind of external mechanical stimulus is exerted via analyzing digital signals. Here, we report a flexible dual-interdigital-electrode sensor (FDES) that consists of two interdigital electrodes and a highly pressure-sensitive porous conductive sponge.
View Article and Find Full Text PDFACS Appl Mater Interfaces
May 2021
Flexible pressure sensors have emerged as an indispensable part of wearable devices due to their application in physiological activity monitoring. To realize long-term on-body service, they are increasingly required for properties of conformability, air permeability, and durability. However, the enhancement of sensitivity remains a challenge for ultrathin capacitive sensors, particularly in the low-pressure region.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
October 2020
Large scale afforestation mainly for erosion control or timber production and a very strict logging ban policy in recent decades led to many over-dense stands and remarkable water yield reduction in the dryland region of the Loess Plateau in northwest China. To guide the integrated forest-water management at stand level, a study on the response of water yield from larch (Larix principis-rupprechtii) plantations to key stand structure and site factors was carried out in the Liupan Mountains. Models of leaf area index (LAI) of forest canopy and stand evapotranspiration (ET) in the growing season were developed and fitted.
View Article and Find Full Text PDFA high-sensitivity temperature sensor based on gold-coated D-shaped photonic crystal fiber is proposed in this paper. To enhance the sensing performances, gold as the surface plasmon resonance material is coated on the polishing surface. The thermosensitive liquid consists of ethanol and chloroform, and it is placed on the outer layer of the photonic crystal fiber.
View Article and Find Full Text PDFTree transpiration (T) is a major water budget component and varies widely due to the integrated effects of many environmental and vegetation factors. This study aimed to separate, quantify, and then integrate the effects of the main individual factors, to improve water use estimation and manage the hydrological impacts of forests. A field study was conducted at 3 plots of larch (Larix principis-rupprechtii) plantation in the semi-humid area of the Liupan Mountains, northwest China.
View Article and Find Full Text PDFThe effect of climate variables (temperature and precipitation) on forest spatial distribution is more prominent in dryland high mountains, where forest distribution is inherently very sensitive to and strongly limited by the substantial spatial heterogeneity of site conditions. Thus, a more reliable prediction of forest distribution under changing environment depends upon an understanding of the joint influence of climatic and topographic factors and their thresholds. This study was conducted on Qinghai spruce forests as dominant tree species in the Qilian Mountains of northwest China.
View Article and Find Full Text PDFForest restoration in dryland mountainous areas is extremely difficult due to dry climate, complex topography and accelerating climate change. Thus, exact identification of suitable sites is required. This study at a small watershed of Qilian Mountains, Northwest China, aimed to determine the important factors and their thresholds limiting the spatial distribution of forests of Qinghai spruce (Picea crassifolia), a locally dominant tree species.
View Article and Find Full Text PDFThe "Grain for Green Project" is a country-wide ecological program to converse marginal cropland to forest, which has been implemented in China since 2002. To quantify influence of this significant vegetation change, Guansihe Hydrological (GSH) Model, a validated physically-based distributed hydrological model, was applied to simulate runoff responses to land use change in the Guansihe watershed that is located in the upper reaches of the Yangtze River basin in Southwestern China with an area of only 21.1 km2.
View Article and Find Full Text PDFActa Neurochir (Wien)
June 2015
Background: In order to reduce the consequences of narcotic-related side effects and provide effective analgesia after craniotomy, we conducted a randomized trial to compare the analgesic efficacy of preemptive scalp infiltrations with 1% lidocaine and 0.5% ropivacaine on the postoperative pain.
Methods: Sixty adult patients scheduled for craniotomy were enrolled.
Small differences in the sensitivity of stomatal conductance to light intensity on leaf surfaces may lead to large differences in total canopy transpiration (EC) with increasing canopy leaf area (L). Typically, the increase of L would more than compensate for the decrease of transpiration per unit of leaf area (EL), resulting in concurrent increase of EC. However, highly shade-intolerant species, such as Larix principis-rupprechtii Mayr.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
August 2013
In order to understand the effects of the structure of forest ecosystem on the hydrological processes, a comparative study by using thermal dissipation technique and hydrological methodology was made on the evapotranspiration (ET) and its components of Larix principis-rupprechtii plantation and Pinus armandi natural forest in two adjacent stands in a small catchment Xiangshuihe of Liupan Mountains during the growth season (May-October) in 2009. Throughout the growth season, the total ET from the plantation was 518.2 mm, which accounted for 104.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
October 2012
From March 2009 to November 2011, an investigation was conducted on the spatiotemporal variation of soil moisture and its effects on the needle-fall in Masson pine (Pinus massoniana) forests in acid rain region of Chongqing, Southeast China, with the corresponding soil moisture thresholds determined. No matter the annual precipitation was abundant, normal or less than average, the seasonal variation of soil moisture in the forests could be obviously divided into four periods, i.e.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
October 2010
Based on field observation and modeling analysis, this paper studied the canopy interception, interception capacity, and some parameters for interception modeling of main forest types in Liupan Mountains of China. For the test main forest types, the ratio of their canopy interception to precipitation ranged from 8.59% to 17.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
March 2009
By the method of sample trees stem analysis, this paper studied the growth process and diameter structure of 21-year-old Larix principis-rupprechtii plantations with the densities of 1200, 1500, and 2000 stems x hm(-2) in the head-water area on the southern slope of Liupan Mountain in Ningxia Hui Autonomous Region. The results showed that there were no significant differences in the growth status of L. principis-rupprechtii stands among the three densities when the stand age was less than 10 years.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
December 2007
The radius and density of soil macropores under eight typical vegetations in Liupan Mountains of Northwest China were studied by using water breakthrough curves and Poiseuille equation. The results indicated that the radii of soil macropores ranged from 0.4 mm to 2.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
September 2005
Canopy interception is an important hydrological process in forest ecosystem, and its modelling is of significance to understand and estimate the rainfall interception by the canopy. In this paper, a canopy rainfall interception model was established by dividing a rain incident into a set of short period, calculating the rainfall distribution intercepted by the canopy, and educing the process of the rain incident. This model considered the effects of the dryness of canopy and trunk on the evaporation from wet canopy and trunk during one rain incident, and introduced two factors, leaf area index (LAI) and surface area of trunk per unit area of ground (SAI), when computing the evaporation.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
September 2005
With heat dissipation probe technique and combined with microlysimeter and hydrological methods, this paper studied the evapotranspiration of secondary Quercus liaotungensis and Tilia paucicostata stands, and its relationship to forest structure from August to September 2004. The results indicated that the stem sap flux density (SFD) of Quercus liaotungensis and Tilia paucicostata changed regularly from day to night in later growth season. In relatively still period (nighttime), the SFD kept low values continuously, usually below 0.
View Article and Find Full Text PDFYing Yong Sheng Tai Xue Bao
May 2002
On the basis of field investigations, the timberline range of Beitai, the Xiaowutai Mountains was carved up, and the changes in the makeup and diversity of plants with the altitude were discussed. The results showed that the timberline with gradual changes in the northern slope of Beitai ranged from 2620-2800 m. In timberline, herbaceous plants were rich, and the diversity was higher than that in coniferous forest and sub-alpine meadow zones.
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