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Gastrolina depressa (Coleoptera: Chrysomelidae) has been found to damage many walnut plants in China. It prefers to feed on the annual leaves of an important economic plant, Pterocarya stenoptera (Fagales: Juglandaceae), and causes extensive cosmetic destruction, even plant death. Nevertheless, its biological characteristics are mostly unknown. In this study, we investigate the harmful and biological characteristics of G. depressa with different developmental stages. The results showed that G. depressa had four developmental stages: egg, larva (1st -3rd instar), pupa, and adult, the life history lasted nine days, with obvious overlapping generations. The food intake of the larvae increased with the increase of the instar, and the maximum food intake of the 3rd instar larvae was 448.19 mm2. The abdomen of the females was enlarged before oviposition, and the average number of eggs laid was 47.63 ± 13.53. Bioassay showed that there was no difference in the search time for the young (2.03, 1.25, 1.15, and 0.91 min) and old leaves (1.68, 1.15, 0.90, and 1.93 min) of P. stenoptera between 1st -3rd instar larvae and adults; the feeding preference of 1st -3rd instar larvae and adults for young leaves was higher than that to old leaves (23.33%, 26.67%, 33.33%, and 21.67%, respectively). The successful selection rates of 1st -3rd instar larvae and adults to young leaves (81.67%, 80%, 85.00%, and 70.00%, respectively) was higher than to old leaves (8.35%, 11.67%, 3.34%, and 11.67%, respectively). [ABSTRACT FROM AUTHOR]

The effects of temperatures and salinities on germination of two halophytes, Kalidium capsicum and Suaeda physophora in northwestern China, were tested, and their seed size and seed production were compared. It was found that seed of Suaeda physophora germinate under 10°C, even about 0°C, and at a wide temperature range of 10–30°C. It showed about 50% germination in the concentration up to 0.7 mol/L NaCl; optimum germination temperature of Kalidium capsicum was between 20°C and 30°C. The concentration of less than 0.3 mol/L NaCl inhibited absolutely its germination. Germination recovery was observed when salinities were reduced and total germination percentage exceeded 90%. Seeds of Kalidium capsicum showed no loss of viability while Suaeda physophora an annual loss of viability of 75% at room temperature. Mean weight of seeds of Suaeda physophora was about 8.5 times of Kalidium capsicum, whereas the number of seeds of the latter was more than 20 times of the former. Suaeda physophora was observed to be dependent on periodic precipitation in germination and seedling growth. It suggests the evident trace of the species with zonation pattern. On the other hand, the germination of Kalidium capsicum was affected by unpredictable rain and inundation. This species might be a type without zonation patterns in halophytes. It was concluded that both species are halophytes, but they are established successfully by different adaptation strategies in the early stage of life history. [ABSTRACT FROM AUTHOR]

Through measuring the above/below-ground growth data of Haloxylon ammodendron seedlings at different stages in hinterland of the desert the results show that the H. ammodendron seedling growth has demonstrated different adaptation characteristics in the continued arid environment with time and space. In May, July, September and October, the growth speed of vertical root is 0.607 cm/d, 0.809 cm/d, 0.155 cm/d and 0.394 cm/d, respectively; the growth speed of height is 0.093 cm/d, 0.076 cm/d, 0.408 cm/d and 136 cm/d, respectively. It is explained that seedlings root system has the growth superiority in space. The maximum growth speed of below-ground (vertical root and horizontal root) of seedling is earlier than that of above-ground (height and horizontal of shoot). In the different periods, the vertical growth speed and the horizontal growth speed of below-ground is 2–10 times and 3–5 times than the height increase speed and the shoot growth speed, respectively. In the whole season, the growth speed of above/below-ground of seedlings shows the alternation growth tendency. At the different periods, the root/shoot ratio of H. ammodendron seedlings is 0.41, 0.3, 0.39 and 0.88. All these characteristics are the comprehensive performance of seedlings’ strategy selection to adapt to the continued arid environment. [ABSTRACT FROM AUTHOR]

River oases at the southern fringe of the Taklamakan desert in NW China are surrounded by belts of spontaneous vegetation that protect the oases from sand drift. As an important source of forage, fuel and construction wood, this foreland vegetation is also a component part of the agricultural system of the oases but has been, and still is, destroyed through overuse. Within a broader study that aimed to provide a basis for a sustainable management of this foreland vegetation, biomass and production were studied in four vegetation types dominated either by Alhagi sparsifolia, Calligonum caput-medusae, Populus euphratica, or Tamarix ramosissima that were thought to occur under different regimes of natural flooding in the foreland of Qira (Cele) oasis, Xinjiang, NW China. Shoot biomass components were closely correlated to basal area ( Calligonum, Populus, Tamarix) or shrub volume and projection area ( Alhagi), enabling non-destructive estimation of stand biomass from shoot diameters or shrub dimensions with sufficient precision using allometric regression equations. Relationships between shoot basal area and biomass of the woody species ( Calligonum, Populus and Tamarix) agreed with predictions by a theoretical model of plant vascular systems, suggesting that they are determined by hydraulic and mechanical requirements for shoot architecture. Average aboveground biomass densities of typical stands in late summer were 2.97 Mg/ha in Alhagi, 3.6 Mg/ha in a row plantation and 10.9 Mg/ha in homogenous stands of Calligonum, 22–29 Mg/ha in 22 year-old Populus forests and 1.9–3.1 Mg/ha in Tamarix-dominated vegetation. Annual aboveground production including wood and assimilation organs ranged from 2.11 to 11.3 Mg/ha in plantations of Calligonum, 3.17 to 6.12 Mg/ha in Populus, and 1.55 to 1.74 Mg/ha (based on total ground area) or 3.10 to 7.15 Mg/ha (in homogenous stands) in Tamarix. Production of Alhagi is equal to peak biomass. A thinning treatment simulating use by the local population enhanced productivity of Calligonum, Populus and Tamarix. A complete harvest of Alhagi in late August decreased production in the following year. An artificial flood irrigation treatment did not sufficiently increase soil water content except in the uppermost layer and had no clear beneficial effect on growth of the four species and even a negative effect on Alhagi, which was due to increased competition from annual species. As biomass and production with or without artificial irrigation were much higher than values expected for rain-fed desert vegetation at a mean annual precipitation of 35 mm, it is concluded that the existence of all vegetation types studied is probably based on permanent access to groundwater and that natural floods or precipitation do not contribute to their water supply. The effects of agricultural groundwater use in the oasis on groundwater in the foreland of the oasis need further study. Sustainable use of this productive vegetation is possible but requires proper management. [ABSTRACT FROM AUTHOR]

The spatial distribution pattern of needle bright disease was mathematically studied. The results showed that it is tally with negative binomial distribution. The infected area and damaged amount can be forecasted with this spatial distribution pattern. Through the study on probability distribution of spatial points for single tree, the method and equations for calculation of the disease index of whole forest belt were determined. [ABSTRACT FROM AUTHOR]

Fixed quadrates were established in different stands. In continued six years, the occurring period, occurring amounts and the relation between epidemic disease and environmental factors were investigated according to spraying laws of spores and accounting measures of disease ranking. The occuring peak period of the disease was from the last ten days of May to the second ten days of June. The epidemic period was from the last ten days of June to the second ten days of July and the initial decease period was from the last ten days of July to the beginning of September. The change of the disease depended on air temperature, relative humidity and precipitation. A multiple linear regression model was established using computer, which can predict the disease index(Y) of 10 days later, with more than 95% reliability [ABSTRACT FROM AUTHOR]

The indoor toxicity determination for several chemicals were carried out on Septoria pini-putmlae and Dothistroma pini. The results showed that Carbendazol, Zineb and Thiophanate-methyl had better effect of killing the fungi. The field experiment indicated that Zineb wettable powder with concentrations of 1∶200, 1∶300 and 1∶500 had 79.2%, 67.2% and 59.7% control results respectively. The control results of 1∶200 Carbendazol wettable powder and 1∶200 Thiophanate-methyl wettable powder were 67.7% and 67% respectively. [ABSTRACT FROM AUTHOR]