《云根》赏析

2002年深秋的一天，作者是在太行山中的岩坡上觅得一黄荆枯根。由于长年风雨剥蚀，虫咬蚁噬，其形怪异奇特。作者惊喜地发现，这是制作根艺的上好材料。经过除污、去腐、砂磨、上漆等工序，作品《云根》很快就完成了。

云到凌霄自有根——读孔祥庚《云根诗词》

不久前，有一位文友送给我一本厚厚的《云根诗词》，作者乃是我的本家孔祥庚，请我给轩轾几句。一页一页翻阅了孔祥庚的《云根诗词》后，我答应了。并非仅是因本家的缘故——这确是一部“斯文在兹”的高水平的诗词著作，不能以一般的“官员诗作”视之。

Dye tracer infiltration technique to investigate macropore flow paths in Maka Mountain, Yunnan Province, China

In order to investigate the differences of macropores vertical distribution under different surface plants, and to assess the influences of root systems, organic matter and texture on macropore flow paths, two dye tracer infiltration experiments were performed in slopes under two different plants(Campylotropis polyantha(Franch.) Schindl vs. Cynodon dactylon(Linn.) Pers). Dye tracer infiltration experiments with field observations and measurements of soil properties were combined. Results show that the discrepancy in macropores distribution between two slopes under different plants is significant. Root systems have significant effects on macropore flow paths distribution and the effect become more pronounced as the diameter of roots become larger. Organic matter and stone are important factors to affect macropores distribution. Root-soil interface, inter-aggregate macropore and stone-soil interface are important macropore flow paths in well vegetated slopes.

Effect of arbuscular mycorrhizal fungi on growth of Gmelina arborea in arsenic-contaminated soil

Arsenic （As） in the soils of South-Eastern Bangladesh is not rely a threat for the health of millions of people but also a problem for plant growth due to its higher concentration in soil. Gmelina arborea Linn. is a promising fast growing tree species in Bangladesh which has dso a potential to be planted in arsenic contaminated areas. This study tssessed the role of arbuscular mycorrhizal （AM） fungi on the growth of 7. arborea in arsenic amended soils at nursery stage. Before sowing ;eeds, soils were treated with four different concentrations （10 mg.kg^-1, 25 mg.kg^-1, 50 mg.kg^-1, and 100 mg.kg^-1） of Arsenic. Growth parameters length of shoot and root, collar diameter, fresh and dry weight of shoot and root） of the plant, and mycorrhizal root colonization and spore population in the rhizosphere soil of G. arborea were recorded. Mycorrhizal seedlings showed better growth than non-mycorrhizal eedlings. Myeorrhizal seedlings planted in soil with 10-mg.kg^-1 arsenic howed best performance in terms of growth, biomass and mycorrhizal ：olonization, compared to other treatments with higher concentration of Lrsenie. With increasing arsenic concentration, growth of seedlings, nycorrhizal infection rate and spore population, all decreased ignificantly （p〈0.05）. The mycorrhizal seedlings had as much as 40% higher increment in total growth and 2.4 times higher increment in biomass compared to non-mycorrhizal seedlings. The study clearly indicated that mycorrhizal inoculation could reduce the harmful effects of arsenic on the initial growth of G. arborea Linn. in degraded soil at nursery stage.

Effects of warming and fertilization interacting with intraspecific competition on fine root traits of Picea asperata

Aims Competition,temperature and nutrient are the most important determinants of tree growth in the cold climate on the eastern Tibetan Plateau.Although many studies have reported their individual effects on tree growth,little is known about how the interactions of competition with fertilization and temperature affect root growth.We aim to test whether climate warming and fertilization promote competition and to explore the functional strategies of Picea asperata in response to the interactions of these factors.Methods We conducted a paired experiment including competition and non-competition treatments under elevated temperature(ET)and fertilization.We measured root traits,including the root tip number over the root surface(RTRS),the root branching events over the root surface(RBRS),the specific root length(SRL),the specific root area(SRA),the total fine root length and area(RL and RA),the root tips(RTs)and root branching(RB)events.These root traits are considered to be indicators of plant resource uptake capacity and root growth.The root biomass and the nutrient concentrations in the roots were also determined.Important Findings The results indicated that ET,fertilization and competition individually enhanced the nitrogen(N)and potassium(K)concentrations in fine roots,but they did not affect fine root biomass or root traits,including RL,RT,RA and RB.However,both temperature and fertilizationz as well as their interaction,interacting with competition increased RL,RA,RT,RB and nutrient uptake.In addition,the SRL,SRA,RTRS and RBRS decreased un der fertilization,the interaction between temperature and competition decreased SRL and SRA,while the other parameters were not affected by temperature or competition.These results indicate that P.asperata maintains a conservative nutrient strategy in response to competition,climate warming,fertilization and their interactions.Our results improve our understanding of the physiological and ecological adaptability of trees to global change.