Báo cáo lâm nghiệp: " Predator/prey ratios: a measure of bark-beetle population status influenced by stand composition in different French stands after the 1999 storms" pps

... site. The comparison of predator/prey ratios between sites and years was carried out using a two-way analysis of variance of the angular trans- form of the predator/prey ratio, with the site, year, ... clearly higher in HA and ST (the two sites with pines) than in GU and 2L, and all ratios tend to increase with years (two-way ANOVA using arc- sine-transformed ratios...

Ngày tải lên: 08/08/2014, 00:22

... 1998. Allozyme and RAPD analysis of the genetic diversity and geographic variation in wild populations of the American chestnut Castanea dentata (Fagaceae). American Journal of Botany, 85: 1013–1021. JIMÉNEZ ... is a wide-spread broad- leaved tree species in the Mediterranean basin. In Spain, it occupies 2,039,563 ha and the main stands are found in the south...

Ngày tải lên: 07/08/2014, 10:22

... height of highest stem, mean height of the stems; mean and minimum distance from the ground to the top of the crown; total basal area (adding together the basal area of all stems); and equivalent ... Iberian Peninsula. In the areas included in the study, mean annual precipitation ranged from 595 to 853 mm, mean annual water deficit (annual potential evapotranspi- rati...

Ngày tải lên: 07/08/2014, 16:21

... particular since these species acclimate to limited water availability by increasing their resistance to cavitation [13], one of the major causes of decline in the botanical species in the absence of ... of the sigmoïd curve was characterized by three critical points, , and which indicated the water potential values that induced the start of the embolism, 50%...

Ngày tải lên: 08/08/2014, 01:22

... simple. In the peripheral layer, where the MS occur, the axial strain increment ( ) can be split into elastic axial strain increment ( ) and axial MS ( ). Generalisation at any point M of is given by: , where ... structure was taken as a reference in order to carry out a numer- ical evaluation of the ITMM biomechanical model. The advantage of this approach was to con...

Ngày tải lên: 08/08/2014, 01:22

... grown in the shade. A higher number of leaves, larger total leaf area and higher dry matter of leaves per 1 plant were de- termined in seedlings grown in the sun. The average area of one leaf was ... the shade after transfer to a gap was still lower after 30 days than in the leaves of plants left in the shade and in control seedlings growing in the...

Ngày tải lên: 07/08/2014, 10:21

... Ager- atina adenophora: Ageraden; Agrostis castellana: Agrocast; Aira caryophyllea: Airacary; Anagallis arvensis: Anagarve; Aphanes micro- carpa: Aphamicr; Arrhenatherum elatium: Arrhelat; Asplenium ... with increasing stand age, and mid to late successional stages (8 to 25 YAH) are discriminated from one another along Axis 1 on the basis of increasing basal area and aerial biomass and...

Ngày tải lên: 07/08/2014, 16:20

... study was to calculate the accumu- lation and the export of nutrients over time in Pinus pinaster (maritime pine) and Pinus radiata (radiata pine) stands under a range of silvicultural alternatives, ... state of the standard stands over time allowed to estimate the stand table before and after thinning, and also the temporal dynamics of nutrient content in tree...

Ngày tải lên: 07/08/2014, 16:21

... to aid survival by reducing the risk of intracellu- lar freezing, owing to the lowering of the cytoplasm freezing point, and by maintaining cell turgor [11]. These strategies contribute to increasing ... 14 h. The resulting frost damage on the surface of the leaves could be visu- ally observed the following day. Leaf damage (LD) was assessed by rating the leaves in...

Ngày tải lên: 07/08/2014, 16:21

... soil quality in sloping oak stands we determined several soil physical, chemical and microbial properties and the abundance of Lumbricidae in mixed oak-hazel stands and adjacent oak monocultures. ... chosen at random and sampled in May 2003. The number of individuals per m² was calculated by sum- ming up the number of earthworms of each single replicate per site. 2.6...

Ngày tải lên: 08/08/2014, 00:21