This study examines the effects of clearcut regeneration with whole-tree harvesting on plant diversity. Three approaches were used to study changes in species composition and structure: (1) forest level, (2) stand level, and (3) diversity indices. Within each approach the forest was stratified into three horizontal vegetative regions based upon height: herb (< 1 m), shrub (between 1 and 5 m), and tree (> 5 m). Between the pre-harvest and 17-year-old forest, the relative percent cover of 3 out of 45 herbaceous and 2 out of 34 woody species were found to be significantly different (df = 3; a = 0.10) in the herb stratum; the importance value (average of relative basal area and stem density) of 2 out of 25 woody species in the shrub stratum; and 1 out of 21 woody species in the tree stratum. Within stands, the three lower quality, 17-year-old stands (SI50 = 12.2, 15.2, and 18.3 m) most resembled their pre-harvest composition; however, increases in ericaceous species were observed in the herb and shrub strata potentially inhibit the future regeneration of tree species. The SI50 = 21.3 m stand incurred the greatest changes in composition potentially due to the lack of fire as a disturbance mechanism. The major mechanism that has caused the shifts in species composition and structure is the change in the microenvironment due to the removal of the overstory, which has shifted the competitive advantages from one species to another. In all cases, diversity indices were not found to be significantly different between the 17-year-old and pre-harvest forests. Diversity indices were therefore determined to have limited use if a manager wants to know specific compositions and/or abundance of species. / Master of Science

Quacking aspen (Populus tremuloides Michx.) is an iconic species in western United States that offers multiple ecosystem services, including carbon sequestration. A shift in forest cover towards coniferous species due to natural succession, land management practices, or climate change may modify soil organic carbon (SOC) dynamics and CO2 emissions. The objectives of this study were to: (i) assess the effects of overstory composition on SOC storage and stability across the aspen-conifer ecotone, (ii) use Fourier transform infrared spectroscopy attenuated total reflectance (FTIR-ATR) to assess whether SOC storage is associated with preferential adsorption of certain organic molecules to the mineral surfaces, and (iii) develop models using near-infrared reflectance spectroscopy (NIRS) to predict aspen- and conifer-derived SOC concentration. Mineral soils (0 – 15 cm) were sampled in pure and mixed aspen and conifer stands in Utah and subjected to physical fractionation to characterize SOC stability (i.e., SOC protected against microbial decomposition), long term laboratory incubations (i.e., SOC decomposability), and hot water extractions (i.e., SOC solubility). Vegetation cover had no effect on SOC storage (47.0 ± 16.5 Mg C ha−1), SOC decomposability (cumulative released CO2-C of 93.2 ± 65.4 g C g−1 C), SOC solubility (9.8 ± 7.2 mg C g−1 C). Mineral-associated SOC (MoM) content was higher under aspen (31.2 ± 15.1 Mg C ha-1) than under mixed (25.7 ± 8.8 Mg C ha−1) and conifer cover (22.8 ± 9.0 Mg C ha−1), indicating that aspen favors long-term SOC storage. FTIR-ATR spectral analysis indicated that higher MoM content under aspen is not due to higher concentration of recalcitrant compounds (e.g., aliphatic and aromatic C), but rather to stabilization of simple molecules (e.g., polysaccharides) of plant or microbial origin. NIRS models performed well during calibration-validation stage (ratio of standard deviation of reference values to standard error of prediction (RPD) ≥ 2). However, model performance decreased during independent validation (RPD = 1.2 – 1.6), probably due to the influence of soil texture, mineralogy, understory vegetation, and land history on SOC spectra. Further improvement of NIRS models could provide insight on SOC dynamics under potential conifer encroachment in semiarid montane forests.

The thesis in the first part deals with the characteristics of major equipment as a source of coarse fodder for preservation. Given the difficult preservability is more prominent characteristic of legumes and their importance in the cultivation of coarse fodder. It describes the significance of clover-grass mixtures in the production of coarse fodder. Methods of harvesting and conservation of grassland biomass. It is also described silage corn, the preservability, harvest methods and importance in animal nutrition. Quality coarse fodder and the factors affecting it. Influence the quality of the biomass input on preservation processes. Furthermore, also deals with the procedures and principles of the production of silage, hay and silage, preservatives and finally summarizes the deterioration of the quality of silage and forage and impact deteriorated for receiving fodder and animal performance.The second part is focused on the monitoring of sensory properties and quality assessment laboratory conserved forage preservation in different ways - loose hay, hay bales, silage pits in silage, clover silage bales and silage in silage pits on lands selected agricultural cooperative. In conclusion, the most important measures designed to improve the quality of canned food.

This thesis summarizes the results obtained from a study of long-term field trials with permanent grassland, which based on Faculty of Agriculture, University of South Bohemia in the České Budějovice between years 2010 - 2013. Permanent grasslands are managed in different ways (mowing, mulching, fallow) and the intensity of exploitation (harvested 1 - 3 times a year, fertilization). The work was focused on the evaluation of changes in growth composition, biomass production and dry matter content of hay variants. Also were evaluated biodiversityand grazing value of the crop stand. Before each harvest (mowing or mulching) was evaluated growth composition of experimental grasslands on an area of 20 m2. Plant species coverage of individual agro botanical groups was estimated by the reduced projective dominance (% D). Harvested biomass of grassland was considered and sample mown every variantof the experiment was dried (dry matter content). Species diversity was expressed as the number of species and species diversity was expressed in the form of Simpson's index. It was also calculated value describing the quality and productivity ofthe crop stand.

In June of 2010, two permanent research plots were established in Forest Park, based on their differing proximities to downtown Portland, Oregon. As part of a long-term ecological research project that seeks to explore the ecological status and human thumbprint on this 5,100 acre forested reserve, the 2010 tree data was investigated for emergent compositional and spatial patterns. Stand composition, tree size, growth rates, and spatial patterns were analyzed, along with ecological and land use histories. Results indicate that the Balch plot, more closely located to the urban center, has different stand composition, condition, and vegetation growth rates, compared to the more rural Miller site. This study supports findings from a study done by Broshot in 2009, where more urban plots demonstrate a different stand composition and recruitment pattern than rural sites. The study is an initial step for exploring questions regarding the ecological status of Forest Park and how land use and disturbance, past and present, shape Portland's forested reserve.