Using ^(137)Cs technique to quantify soil conservation capacities of different ecosystems in Wolong Natural Reserve, southwestern China

Reliable information about soil conservation capacities of different natural ecosystems is an important reference for the design of targeted erosion and sediment control strategies. The objective of this paper is to quantify the soil conservation capacities of different natural ecosystems that can represent dif-ferent climatic zones. The 137Cs technique has been used to estimate soil redistribution rates in differ-ent natural ecosystems over the past 40 years in Wolong Nature Reserve. The reserve, transiting from the Chengdu plain to the Qinghai-Tibet plateau, maintains rich ecosystems from subtropical to frigid. The net soil erosion rates of 5 selected ecosystems that represent a warm coniferous-broadleaf-mixed forest, a cold-resistant deciduous taiga forest, a cold-resistant shrub, an evergreen cold-resistant taiga forest, and an alpine meadow are 0.17, 0.16, 0.13, 0.11 and 0.06 kg·m-2·a-1, respectively. Their soil con-servation capacities are reversed in order. The reference inventories for ^(137)Cs in different ecosystems range from 1658 to 3707 Bq·m-2 with the altitude. Results of this study indicate that any attempt to de-velop effective erosion and sediment strategies in areas with similar climates should consider natural ecosystem types.

Ramet Population Structure of Fargesia nitida （Mitford） Keng f. et Yi in Different Successional Stands of the Subalpine Coniferous Forest in Wolong Nature Reserve

Forest structure and succession in Wolong Nature Reserve is influenced by the understory dwarf bamboo population. However, less is known about how the forest succession affects the dwarf bamboo population. To examine the bamboo ramet population growth of Fargesla nitida （Mltford） Keng f. et Yi and to determine how ramet population structure varies along the succession of coniferous forest, we sampled ramet populations of F. nitida from the following three successional stages： （i） a deciduous broad-leaved （BL） stand; （ii） a mixed broad-leaved coniferous （MI） stand; and （ill） a coniferous （CF） stand. We investigated the population structure, biomass allocation, and morphological characteristics of the bamboo ramet among the three stand types. Clonal ramets, constituting the bamboo population, tended to become short and small with succession. The ramet changed towards having a greater mass investment in leaves, branches and underground roots and rhizomes rather than in the culm. With respect to leaf traits, individual leaf mass and area in the BL stand were markedly bigger than those In both the MI and CF stands, except for no significant difference in specific leaf area. The age distribution showed that the bamboo population approached an older age with succession. The results demonstrate that the ramet population structure of F. nitida is unstable and its growth performance is inhibited by succession.

Medicinal Plants Harvesting in Wolong National Nature Reserve

A combination of sample surveys and questionnaires were used to investigate the harvesting of wild medicinal plants （WMP） in Wolong National Nature Reserve （WNNR） from August 2014 to July 2015. These surveys showed that up to 20 families and 45 species of WMP were harvested in WNNR. Gastrodia elata, Paris polyphylla, Fritillaria thun-bergli, Rheum officinale, Rhodiola rosea, Saussurea medusa, Notopterygium root, Radix Ginseng, Buddha＇s palm were harvested intensely. The harvesting, which occurred mainly in autumn and winter （from June to October） in the test area, buffer area and core area, was located mostly in the residential and crop production areas of Wolong Town and Gengda Town, and in the timberline, alpine meadows and scree areas of Dengshenggou Ravine and Balangshan Mountain （specifically in Dengshenggou, Tangfang, Tizigou Ravine, Wei- jiagou Ravine and Reshuihe River areas）. Among all the harvesters, 58% came from inside the WNNR, and 42% came from outside the WNNR; 87% were male, and 13% were female; 6% were under the age of 18, 69% were 19-45 years old, 19% were 46-65 years old, 6% were over 66 years old. The main purpose of harvesting was commercial sale to increase household income. Based on the analysis and discussion of the results, comprehensive management measures were introduced to strengthen the awareness and efficacy of laws and regulations, integrate the enforcement of these laws, establish and strengthen inspections. Skills training and the domestication of the wild medicinal materials were used to encourage the surplus labor force to avoid excessive harvesting and move into other agricultural endeavors.

An integrated approach to understanding the linkages between ecosystem services and human well-being

In order to use science to manage human-nature interactions,we need much more nuanced,and when possible,quantitative,analyses of the interplay among ecosystem services(ES),human well-being(HWB),and drivers of both ecosystem structure and function,as well as HWB.Despite a growing interest and extensive efforts in ES research in the past decade,systematic and quantitative work on the linkages between ES and HWB is rare in existing literature,largely due to the lack of use of quantitative indicators and integrated models.Here,we integrated indicators of human dependence on ES,of HWB,and of direct and indirect drivers of both using data from household surveys carried out atWolong Nature Reserve,China.We examined how human dependence on ES and HWB might be affected by direct drivers,such as a natural disaster,and how human dependence on ES and direct and indirect drivers might affect HWB.Our results show that the direct driver(i.e.,Wenchuan Earthquake)significantly affected both households’dependence on ES and their well-being.Such impacts differed across various dimensions of ES and well-being as indicated by subindices.Those disadvantaged households with lower access to multiple forms of capital,more property damages,or larger revenue reductions also experienced greater losses in HWB.Diversifying human dependence on ES helps to mitigate disaster impacts on HWB.Our findings offer strong empirical evidence that the construction of quantitative indicators for ES and HWB,especially integrated models using them,is a viable approach for advancing the understanding of linkages between ES and HWB.

Response of clonal plasticity of Fargesia nitida to different canopy conditions of subalpine coniferous forest

The aim of this study is to explore the effects of canopy conditions on clump and culm numbers,and the morphological plasticity and biomass distribution patterns of the dwarf bamboo species Fargesia nitida.Specifically,we investigated the effects of canopy conditions on the growth and morphological characteristics of F.nitida,and the adaptive responses of F.nitida to different canopy conditions and its ecological senses.The results indicate that forest canopy had a significant effect on the genet density and culm number per clump,while it did not affect the ramet density.Clumps tended to be few and large in gaps and forest edge plots,and small under forest understory plots.The ramets showed an even distribution under the closed canopy,and cluster distribution under gaps and forest edge plots.The forest canopy had a significant effect on both the ramets’biomass and biomass allocation.Favourable light conditions promoted ramet growth and biomass accumulation.Greater amounts of biomass in gaps and forest edge plots were shown by the higher number of culms per clump and the diameter of these culms.Under closed canopy,the bamboos increased their branching angle,leaf biomass allocation,specific leaf area and leaf area ratio to exploit more favourable light conditions in these locations.The spacer length,specific spacer length and spacer branching angles all showed significant differences between gaps and closed canopy conditions.The larger specific spacer length and spacer branching angle were beneficial for bamboo growth,scattering the ramets and exploiting more favourable light conditions.In summary,this study shows that to varying degrees,F.nitida exhibits both a wide ecological amplitude and high degree of morphological plasticity in response to differing forest canopy conditions.Moreover,the changes in plasticity enable the plants to optimize their light usage efficiency to promote growth and increase access to resources available in heterogeneous light environments.