Gormsenolsen4676

We monitored seed rain in three forest types for two years (2018-2019) in the central part of Greater Xing'an Mountains, and analyzed the seasonal seed rain dynamics, deciduous dynamics, seed rain thousand-grain weight, inter-annual variation of seed rain, and spatial pattern of seed rain of the main tree species in different forest types. The results showed that seed rain of Larix gmelinii and Betula platyphylla in each forest type showed unimodal distribution. The leaf litter amount of coniferous and broad-leaved species (L. gmelinii, Pinus sylvestris var. mongolica, Picea koraiensis, B. platyphylla and Populus davidiana) also showed obvious seasonal dynamics, with a peak in the middle and early September. In coniferous and broadleaved mixed forests and coniferous forests, the 1000-grain weight of L. gmelinii at the peak period was significantly greater than that at the initial and final stages. The 1000-grain weight of B. platyphylla in the three forest types did not show obvious seasonal variation. Seed rain of L. gmelinii and B. check details platyphylla showed obvious inter-annual change. The year 2018 was a large seed set year, whereas 2019 was a year with small seed set. The spatial pattern of all seed rain was mainly dominated by aggregated distribution in both years, which was consistent with that of seedlings and saplings.This study aimed at understanding the differences in traits of functional twigs and leaves of a typical alpine shrub species, Rhododendron przewalskii, at Kaka Mountain in the headwater region of Minjiang River. Leaf and twig traits were compared for shrubs at different growth stages (flower bud stage and flowering stage) and altitude (3600 m and 3800 m). The effects of spatial heterogeneity on their correlations and trade-offs were evaluated at leaf and twig levels, respectively. Our results showed that twig length was significantly longer at low altitude than high altitude for the shubs at the same growth stage. The number and mass of flowers at flowering stage were significantly higher at high altitude than those at low altitude. At the same altitude, twig mass, number of leaves, total leaf mass, total leaf area and total petiole mass were all significantly greater at the flower bud stage than those at the flowering stage, while the individual leaf mass and individual petiole mass at flower bud stage were significantly smaller than those at flowering stage. Compared with the flower bud stage, the proportion of leaf mass decreased by 13% at the flowering stage, while biomass proportion of twig significantly increased. At the flower bud stage, twig mass had a higher contribution to total twig mass. In contrast, the contribution of total leaf mass to total twig mass was higher at flowering stage. More biomass of leaf was allocated to individual leaf mass at flower bud stage. More biomass of leaf was allocated to individual petiole mass and individual leaf mass at flowering stage at low altitude and high altitude, respectively. At low altitude, allometric growth patterns presented between twig mass and total leaf area, total leaf mass. Similarly, individual petiole mass and individual leaf area had allometric growth. Our results indicated that the functional traits of twigs and leaves varied across both altitude and plant growth stage.A water-controlled experiment with four treatments (no rain, half raining, natural raining and double raining) was carried out in a Platycladus orientalis forest. The factors including soil water content (SWC), precipitation, sap flow density (Js), leaf area index (LAI), vapor pressure deficit (VPD) were monitored during August 2016 to August 2017. We further analyzed the response of canopy stomatal conductance (gs) to changes of SWC. The results showed that the SWC of plots (half, natural and double raining) showed a positive correlation with precipitation, and the range of SWC was 4.9%-16.0%, 7.2%-22.9%, 7.4%-29.6%, respectively. The SWC in the plot with no rain decreased by 50% from August to October. The daily gs reached a peak of 166.64 mmol·m-2·s-1 at 1400 in July, which was significantly higher than other months. A bimodal phenomenon occurred. The daily gs reached a peak of 54.1 mmol·m-2·s-1 at 1200 in January. Under the three rain plots, diurnal variation of gs and SWC showed a negative quadratic correlation. The SWC corresponding to the peak of gs was 8.5%, 12.5% and 18.5%, respectively, close to the annual average SWC. Sensitivity (δ) of gs to VPD /reference canopy stomatal conductance (gsref) was more than or equal to 0.6 in different water-controlled plots, indicating that soil water condition was more suitable for water demand of P. orientalis. When SWC was between 3.7% and 7.5%, the δ and gsref increased rapidly, indicating that stomata had better regulation ability, and that plant stomata was more sensitive to VPD. When SWC increased to 11%, SWC alteration did not affect the response sensitivity of gsrefand gs to VPD. There might be a SWC threshold value for the adaptation of P. orientalis. By closing or reducing stomatal aperture, leaf water potential decreased, P. orientalis could adapt to excessive VPD and avoid excessive transpiration, which was more effective in regulating transpiration.The complexity and uncertainty of forest regeneration is crucial for predicting forest ecosystem dynamics. A natural regeneration model of pine-oak forests in Qinling Mountains was constructed with competition, climate and topography factors using Bayesian statistics and global sensitivity analysis (GSA). The alternative models were based on Poisson, negative binomial (NB), zero-inflated Poisson (ZIP), and zero-inflated negative binomial (ZINB) models. According to the uncertainty of model parameter transfer, the analysis results were quantified, and the dominant factors of small probability events affecting forest regeneration were explained. The results showed that the ZINB model was the best one in the simulation of Pinus tabuliformis and Quercus aliena var. acuteserrata. Stand basal area, light interception, slope location and minimum temperature during growing season were the most critical factors affecting natural regeneration of P. tabuliformis, while stand basal area, cosine of aspect interacted with ature of the driest quarter. The ZINB model based on Bayesian methods could effectively quantify the major factors driving forest regeneration and interpret the uncertainty propagated from parameters, which was useful for predicting forest regeneration.Plots were set on the top, middle and bottom of the stony desert alluvial fan in the middle of southern foothills of the Tianshan Mountains. With plant height and crown size as indicators, the spatial heterogeneity of Ephedra przewalskii populations in the stony desert were studied using geostatistical methods. Understanding the spatial heterogeneity characteristics of E. przewalskii populations could provide scientific basis for vegetation protection and ecological restoration in stony deserts. The results showed that E. przewalskii had a patchy distribution at the top of the alluvial fan. At the middle and bottom of the alluvial fan, it showed a banded distribution. The band width in the middle was larger than that at the bottom. From the top to the bottom of the alluvial fan, the overall plant height and crown size of E. przewalskii populations decreased first and then increased. The average plant height on the top, middle and bottom of the alluvial fan was 40.34, 21.07, 36.96 cm, and the crown size were 1.09, 0.80, 1.43 m2, respectively. The best fitting models for plant height of E. przewalskii were the exponential model, the exponential model, and the linear model at the top, middle and the bottom of the alluvial fan, respectively, while the best fitting models for crown size were exponential model, spherical model, and linear model. From the top to the bottom of the alluvial fan, the fractal dimension value of plant height and crown size of E. przewalskii ranged from 1.909 to 1.889, indicating that the spatial pattern of E. przewalskii populations was simple and the spatial homogeneity was high. From the top to the bottom of the alluvial fan, the spatial distance of the anisotropy of plant height and crown size of E. przewalskii gradually shortened. At the top, middle and bottom of the alluvial fan, the spatial distances where the plant height and crown showed anisotropy were >60 m, 42-46 m and 23-27 m, respectively.A 140 m×120 m plot was set in a secondary forest with more than 30 years natural reco-very after abandonment in Ziyun Miao and Buyi Autonomous County, a typical karst area in Guizhou Province. We investigated the spatial distribution and interspecific associations of regenerating sapling population using spatial point pattern analytical method. There were 1291 saplings with 39 tree species. Betula luminifera, Platycarya strobilacea, Liquidambar formosana, Pinus massoniana and Populus davidiana were the dominant populations of regenerating saplings, accounting for 83.7% of the saplings and 77.8% of the total importance value. The spatial distributions of B. luminifera, P. strobilacea and L. formosana were strongly aggregated at a spatial scale of 0-60 m, while the spatial distributions of P. massoniana and P. davidiana were aggregated at small scale and randomly distributed at large scale. The spatial associations among those dominant populations were mostly positively correlated, with positive correlations of P. massoniana with L. formosana and P. davidiana at small scale but no associations at large scale. In conclusion, the spatial distributions and interspecific associations differed among the dominant sapling populations, due to the different biological characteristics of different tree species, habitats and uses of spatial resources. Most of the stands investigated were dominated by pioneering species, with poor stand quality and unstable community structure. A mixed forest dominated by P. massoniana and B. luminifera would be the next stage of succession. We recommended that measures of forest management should be adopted to accelerate vegetation restoration.We analyzed the variation trend of growing season length (GSL) of different periods in provinces (regions) of China and the corresponding movement velocity of GSL isolines at 150, 200, 250, 300 and 350 days, based on daily mean temperature data of 822 meteorological stations from 1951 to 2017. In this study, the definition of GSL given by the world meteorological organization was adopted, together with Slope, Hurst and Mann-Kendall indices. The results showed that the GSL in northern China changed significantly during 1951-2017. The extension of GSL was faster in the north than the south, and faster in high-altitude areas than low-altitude ones. The trend of future GSL change in most regions of China converged with the current extension trend. The extension of GSL in northern provinces (regions) was generally 0.1-0.2 d·a-1, of which the fastest was Tibet with a speed of 0.44 d·a-1. The period 1981-2000 was the most changeable time of GSL in Chinese provinces (regions). The growing season start (GSS) of all prrch.There are increasing numbers of parents who identify as lesbian, gay, bisexual and transgender (LGBT), but there is little research on the experiences of LGBT parents when accessing healthcare for their children. The aims of this literature review were to identify existing articles on the topic, explore LGBT parents' experiences and draw implications for practice. The review included ten studies published from 1995 onwards and conducted in Australia, Sweden, the US and Finland. Many LGBT parents had positive experiences while others had encountered overt homophobia. However, there remained an underlying sense of heteronormativity, with many healthcare professionals making heterosexist assumptions and healthcare forms being heterocentric. The documentation used in healthcare settings should be adapted and healthcare professionals should improve their awareness on this issue and have training on how to recognise and include LGBT families. The review did not identify any studies on this subject from the UK, which suggests that research on the healthcare experiences of families with LGBT parents in the UK is required.