Forests are complex ecosystems that develop over centuries through the interactions between organisms and biogeochemical cycles of elements occurring in the soil-atmosphere continuum. The biomass and structure of a forest stand is involved in several ecosystem processes and has been used as an indicator of forest health and productivity. The forest biomass is a key component of the carbon cycle...

The aim of this study was to examine the ecological plausibility of the "krill surplus" hypothesis and the effects of whaling on the Southern Ocean food web using mass-balance ecosystem modelling. The depletion trajectory and unexploited biomass of each rorqual population in the Antarctic was reconstructed using yearly catch records and a set of species-specific surplus production models. The r...

Ecosystem and biogeochemical responses to anthropogenic stressors are the result of complex interactions between plants and microbes. A mechanistic understanding of how plant traits influence microbial processes is needed in order to predict the ecosystem-level effects of natural or anthropogenic change. This is particularly true in wetland ecosystems, where plants alter the availability of bot...

The potential of biological nitrogen fixation (BNF) to provide sufficient N for production has encouraged re-appraisal of cropping systems that deploy legumes. It has been argued that legume-derived N can maintain productivity as an alternative to the application of mineral fertilizer, although few studies have systematically evaluated the effect of optimizing the balance between legumes and no...

This thesis describes research done on two novel algae cultivation systems. The first system was an attached algal growth system to facilitate biomass harvest with improved biomass yield. In the attached system, algal cells were grown on the surface of a material rotating between the nutrient-rich liquid phase and the carbon dioxide-rich gaseous phase. The algal cells from the attached growth s...

Seasonal abundance and distribution of hypogeous fungi associated with selected stands of ponderosa pine on the Coconino and Kaibab Plateaus, Arizona, were examined using a new method that reduced the time and area needed to sample nonrandomly dispersed fungal sporocarps. As measured monthly over three years, peak sporocarp production occurred both spring and fall with the greatest species rich...

Climatic effects on annual net carbon gain, stem biomass and annual transpiration were simulated for Pinus radiata D. Don at Canberra and Mt. Gambier. Simulations were conducted with an existing process-based forest growth model (BIOMASS, Model 1) and with a modified version of the BIOMASS model (Model 2) in which response functions for carbon assimilation and leaf conductance were replaced wit...

An annual cycle of biomass and productivity of wild celery (Vallisneria americana) was studied in Kings Bay, FL, USA. In situ growth rates were measured monthly between March 2001 and June 2002 in high-density stands, using a modified hole-punching technique, and applied to shoot density data to obtain areal estimates of production. Mean shoot density varied greatly over the study period, rangi...

Despite the advantages of plant-based transient expression systems relative to microbial or mammalian cell systems, the commercial production of recombinant proteins using plants has not yet been achieved to any significant extent. One of the challenges has been the lack of published data on the costs of manufacture for products other than biopharmaceuticals. In this study, we report on the tec...

0 In this study the potential role of competition in in~uencing the distribution of three displaced native perennial grasses across complex gradients of plant productivity and species composition was investigated in Michigan old!_elds[ To do this plant removal and propagule addition experiments were conducted at nine old!_eld sites to examine the e}ects of living plant neighbours and litter on ...