Résumé
To clarify the difference of soil moisture characteristics between mixed broad leaf-conifer forest soil and artificial cultivation of Notopterygium incisum, the HYPROP system and the dew point potential meter were used to determine soil water retention curves(SWRC) for samples of two horizons(i.e. 2-7 cm, 10-15 cm). The basic physical and chemical properties of soil and its water characteristic parameters were also determined. The result showed as fllows:①The bulk density of mixed coniferous-broad leaf forest soil was between 0.33 and 0.52 g·cm~(-3), significantly lower than the corresponding value of field soil(1.01-1.18 g·cm~(-3))(P<0.05), While the organic matter content was significantly higher than the corresponding value of field soil(P<0.05). ②The saturated water content(θ_s), field water holding capacity(θ_(FC)) and Water that can be effectively utilized by plants(θ_(PAC)) of mixed coniferous-broadleaved forest soil were significantly higher than the corresponding value of field soil(P<0.05), while the retained water content(θ_r) value that cannot be effectively utilized by plants was significantly lower than that of field soil(P<0.05). ③The values of structural porosity(0.13-0.24 cm~3·cm~(-3)) and Matrix porosity(0.34-0.44 cm~3·cm~(-3)) of mixed coniferous-broadleaved forest soil were higher than the corresponding values of field soil. Therefore, with low bulk density and high content of organic matter, mixed coniferous-broadleaved forest soil can store more water in soil in the form of effective water to meet the needs of plants for water, thus possibly forming high quality medicinal materials of Notopterygii Rhizoma et Radix. In conclusion, the results of this study can provide theoretical basis guidance for soil structure improvement and water management to form high quality medicinal materials in the artificial cultivation of N. incisum.
Sujets)
Apiaceae , Chine , Forêts , Sol , Tracheobionta , EauRésumé
Los descortezadores Dendroctonus frontalis (Coleoptera: Scolytidae) son un grupo de coleópteros estrechamente ligado a las masas forestales y son una de las plagas más dañinas en México, ocasionando que la cobertura forestal se reduzca considerablemente. Adicionalmente factores como el cambio climático, favorecen el aumento en las poblaciones de escarabajos descortezadores del género Dendroctonus. Por lo anterior es conveniente conocer la variación poblacional de descortezadores, particularmente de Dendroctonus frontalis, cuyas poblaciones dependen de la variabilidad climática que influye en su abundancia. Teniendo como hipótesis que la altitud y las variables ambientales afectan el comportamiento en la abundancia de D. frontalis, se planteó como objetivo estimar la variación espacio-temporal de poblaciones de D. frontalis en bosques de pino a diferentes altitudes. El estudio se realizó en la comunidad de Durango, Zimapán, Hidalgo, México. Se utilizó un diseño experimental de parcelas apareadas con dos tratamientos, de feromona y testigo. Se colocaron siete trampas con ambos tratamientos en un rango de 1 568 a 2 117 m.s.n.m. para determinar la abundancia altitudinal de D. frontalis. El muestreo se llevó a cabo de enero a diciembre 2015. Se obtuvo una relación positiva entre la abundancia de D. frontalis y el gradiente altitudinal y respecto a la abundancia de D. frontalis y la temperatura se observó una relación moderada, pero no significativa; de la misma forma para la precipitación media anual. La relación con la temperatura media máxima y el balance de precipitación de primavera/verano fueron estadísticamente significativos. Se presentó una tendencia positiva en la abundancia de D. frontalis de acuerdo al índice anual de aridez, por lo cual se espera que con el aumento de las temperaturas el estrés en la vegetación de los bosques sea mayor, favoreciendo el incremento de las poblaciones de escarabajos descortezadores.
The bark beetles Dendroctonus frontalis (Coleoptera: Scolytidae) are a group of coleoptera closely linked to forest masses, and one of the most harmful pests in Mexico, causing the forest cover to be considerably reduced. Additionally factors such as climate change, favor the increase in populations of bark beetles of the genus Dendroctonus. Taking as a hypothesis that altitude and environmental variables affect the behavior in the abundance of D. frontalis, the objective was to estimate the temporary-spatial variation of D. frontalis populations in pine forests at different altitudes. The study was conducted in the community of Durango, Zimapán, Hidalgo, Mexico. An experimental design of paired plots with two treatments was used, pheromone and control. Seven traps were placed with both treatments in a range of 1 568 to 2 117 m.a.s.l. to determine the altitudinal abundance of D. frontalis. The sampling was realized from January to December 2015. A positive relationship was observed between the abundance of D. frontalis and the altitudinal gradient. About the abundance of D. frontalis and the temperature, a moderate but not significant relationship was observed in the same way for the average annual precipitation. The relation with the maximum average temperature and the spring summer precipitation balance were statistically significant. There was a positive trend on the abundance of D. frontalis according to the annual aridity index, which is why it is expected that the increase of temperatures the stress in the vegetation of the forests will be greater, favoring the increase of bark beetles populations.