Above-ground Biomass Recovery in Managed Tropical Forest in the Jari Valley, Eastern Amazon

Tropical forests play an important role in maintaining the regional rainfall regime and global climate, besides representing a significant stock of carbon. This study aimed at evaluate above-ground biomass (AGB) recovery, after reduced-impact logging (RIL) in a managed forest on the Jari River valley. The data were collected in 15 plots (100 m × 100 m) in the management area of the Jari Florestal Company. To estimate AGB we used a local equation adjusted for forests in the eastern Amazon. AGB before logging ranged from 157.9 Mg ha-1 to 619.9 Mg ha-1, with an average of 362.5 Mg ha-1. AGB after logging ranged from 151.2 Mg ha-1 to 632.8 Mg ha-1, with an average of 322.4 Mg ha-1. The time of monitoring of the plots and logging intensity were the main factors that influenced the recovery of the AGB. In 12 years after the RIL, the forest was able to recover its initial stocks of AGB, in places of low exploitation intensity.

An Analysis and Testing of Functional Availability Military Vehicles, in the Aspect of Reliability

The paper pertains to matters related to the quantification of functional availability of military vehicles, with reference to exploitation intensity and reliability aspects. The conducted exploitation research paved the way for elaborating methods of determining functional availability for military vehicles, in particular focusing on exploitation intensity and reliability. The essential research was conducted using the developed mathematical model based on the probabilistic, stochastic Markov process, which allowed modelling the process of changes in the exploitation states of military vehicles. In the course of the research, which enabled the authors to estimate the functional availability value, four-layered probes of the military vehicles were used (different types and makes), from the second exploitation phase, with varied mileage from the beginning of the exploitation and average mileage per year.

Effect of Cutting Pattern and Fertilization Level on Species Diversity and Evaluation of Grassland Quality

The effects of fertilization level and cutting pattern on the species diversity and quality of a meadow stand were assessed in 2004–2012 in the small plot trial established in 2003 in Vatín, Vysočina Region, Czech Republic. Four levels of fertilization (none; N0 + P30 + K60 kg∙ha−1; N90 + P30 + K60 kg∙ha−1; N180 + P30 + K60 kg∙ha−1) were combined with four treatments of exploitation intensity (4 cuts per year, first cut on 15th May, every next after 45 days; 3 cuts per year, first cut on 30th May, every next after 60 days; 2 cuts per year, first cut on 15th June, next after 90 days; 2 cuts per year, first cut on 30th June, next after 90 days). Numbers of species, Simpson’s diversity index and evaluation of grassland quality according to Novák (2004) were evaluated. Numbers of species and Simpson’s diversity index were significantly affected by both fertilization level and cutting pattern. Species richness decreased along with increasing fertilization rates from 29.4 (no fertilization) to 27.8 (N180PK). When comparing cutting pattern treatments the highest species richness was found in four-cut swards (29.6 in average of fertilization levels) and it declines towards late double-cut regime (27.2). The Simpson’s index generally increased from two-cut swards to four-cut and from fertilized treatments to control. Grassland quality was significantly affected by cutting pattern. Values increased from four-cut swards (38.1) to two-cut ones (43.8 and 44.0 in early and late harvest respectively).

Numerical Simulation and Prediction of High Fluorine Groundwater Transport in Zhangye Basin

Simulate Feflow with finite element method, and establish flow model and solute transport model of high fluorine groundwater area in Zhangye Basin. Predicting groundwater system response under different exploitation scheme, and evaluating the risk of deep low fluorine groundwater polluted by shallow high fluorine groundwater. The results showed that, firstly, the existing exploitation intensity and the increasing exploitation intensity of the local planning would lead to groundwater table descent, for the deep groundwater head is higher than phreatic water in above scheme, the polluted risk of low fluorine freshwater is low. Secondly, low and deep groundwater “cross strata” caused by well completion technology would lead to deep low fluorine freshwater polluted, and the high fluorine polluted area caused by single well is limited, but the polluted risk of low fluorine aquifer is increasing with that confined water head is lower than phreatic water in local concentrated excess exploitation area. Propose the measures and suggestions of the groundwater sustainable utilization.

Effect of fertilization and harvest frequency on floristic composition and yields of meadow stand

The effect of fertilization and the harvest frequency on production and floristic characteristics of a meadow stand were assessed in a small plot trial established in 2003 in Vatín, Vysočina Region, the Czech Republic. Four levels of fertilization (none; N0 + P30 + K60 kg∙ha−1; N90 + P30 + K60 kg∙ha−1; N180 + P30 + K60 kg∙ha−1) were combined with four treatments of exploitation intensity (4 cuts per year, first cut on 15th May, every next after 45 days; 3 cuts per year, first cut on 30th May, every next after 60 days; 2 cuts per year, first cut on 15th June, next after 90 days; 2 cuts per year, first cut on 30th June, next after 90 days). Production of dry matter and proportions of guilds (grasses, legumes, and other species) were evaluated. Data from 2009–2011 were used in this paper. Yields of the dry matter increased along with increasing amounts of nutrients supplied and ranged from 3.8 t∙ha−1 (non-fertilized) to 9.1 t∙ha−1 (N180PK). The nutrition level had a significant effect on spread of grasses, which reached maximal proportion of 52.3 % under N180PK fertilization compared to 42.1% on non-fertilized plots. On the contrary, legumes flourished well in treatments without N-supply, attaining proportion of 6.8 % and 5.1 % on PK-fertilized and non-fertilized plot, respectively. With regard to the exploitation intensity grasses profited from extensive management by contrast to the group of other species which reached its maximum in swards harvested four times a year. Proportions of legumes did not show significant dependence on the cutting frequency.