During the past fifteen years, non-timber or special forest products have become an important economic resource in the Pacific Northwest. These products are primarily derived from understory species and contribute approximately $200 million to the regional economy. Medicinal plants are a little researched component of the non-timber forest product industry that relies on cultivated and wildcrafted (or wild-collected) medicinal plant species. This study examines the commercial extraction of wildcrafted medicinal plants from Mount Hood National Forest. Specifically, this study documents the medicinal plant species extracted from Mount Hood National Forest, their annual yield amounts, harvesting methods, and the changes in cover of target species after harvest. This research uses survey data obtained from employees of two herbal companies and representatives of the U.S. Forest Service to describe medicinal plant extraction and administration as it pertains to the commercial extraction of plant species from Mount Hood National Forest. Field data were also used to examine changes in plant cover for four medicinal plant species (kinnikinnick, yarrow, Oregon grape and valerian) following harvest. Field results indicate that medicinal plant cover decreased significantly in all but one harvested sampling unit. Permanent unit markers were established at all the study sites to provide opportunities for long-term monitoring of target species responses to harvest. Eleven medicinal plant species are commonly collected for commercial purposes from Mount Hood National Forest. The general lack of regulation and enforcement of commercial medicinal plant extraction coupled with an increasing demand for wildcrafted medicinal plants warrant a need for increased collaboration between regulatory agencies, herbal companies, and the general public. Additional management and research recommendations regarding the ecological impacts of medicinal plant removal are also presented.

This quantitative study seeks to determine the impacts of harvesting three plant species traditionally used for wound healing during circumcision. Three localities where these plant species occur have been identified. The population size for each species was determined and an assessment of the extent of harvesting was determined through repeated assessment of marked plants. A significant harvest of these species resulted in the unsustainable use of our natural resources. Out of 25 Boophone disticha plants marked, only one plant was remaining after two circumcision seasons. The Brunsvigia grandiflora and Scadoxus multiflorus populations monitored disappeared completely, with no single marked plant found after two circumcision seasons. Growth rates of wild populations of Boophone disticha and cultivated Brunsvigia grandiflora and Scadoxus multiflorus plants were determined. The seedling bulbs of Brunsvigia grandiflora grew significantly more slowly at less than 0.6 cm per year, while Scadoxus multiflorus grew faster at over 1 cm per year. A model for population dynamics of the three plant species was designed which showed that the plants are being harvested before they even flower. It is therefore recommended in this study that a conservation plan for these plant species must be done to save the little that is left in the wild before they become critically endangered.

Thesis (Ph.D. Agriculture (Plant Production)) -- University of Limpopo, 2022 / The unique phytochemical composition of the medicinal plant cancer bush (Sutherlandia frutescens) have made its foliage to gain much attention in South Africa due to its health benefits. In situ harvesting of the plant parts of this important species serve as one potential strategy to avert its extinction through whole plant harvesting, a common practice by rural communities. However, such a strategy is limited by lack of information on the agronomic requirements of the plant species and its susceptibility to root-knot (Meloidogyne species) nematodes. The objectives of the study were four-fold, namely, to: (1) identify nodulation bacteria associated with wild S. frutescens using morphological and biochemical techniques, (2) assess the efficacy of the nodulation isolates from different centres of biodiversity of S. frutescens in Limpopo Province, South Africa (3) test the compatibility of cucurbitacin-containing phytonematicides on S. frutescens for managing population densities of Meloidogyne species and (4) determine the nutritional water productivity (NWP) of S. frutescens in association with water scarcity of the region where the plant species originated. In achieving Objective 1, nodules from S. frutescens roots were washed in distilled water and healthy, undamaged, firm and pink nodules were sterilised. Aseptic nodules from S. frutescens roots and commercial strains were transferred into a smasher biomerieux polythene bag containing 10 ml distilled water and crashed to produce a milky suspension the milky suspension was streaked on Yeast extract mannitol agar (YEMA). After gram reaction, colony characterisation includes the investigation of shape, colour, configuration, elevation and margin of bacterial colony as observed in colonies on nutrient agar plates of overnight grown microorganisms using a microscope. The medium for biochemical test was prepared, inoculated with 5 μl purified xxv bacterial cultures and incubated at 37°C for 48 h. Identification of the bacterial isolates was performed using VITEK 2 Systems (bioMérieux, Inc., North Carolina, USA). Using morphological and biochemical techniques, the bacterial species associated with roots of S. frutescens in the wild were assayed primarily those in the genera Raoutella ornithinolytica and Enterobacter cloacae species dissolvens. The VITEK 2 Systems confirmed the identification of the bacterial species from 80 to 96% of the samples. Three species were confirmed from another sampling area, Sphingomonas paucimobills, Raoutella ornithinolytica and Enterobacter cloacae species dissolvens from by 86 to 96% of the samples. In achieving Objective 2, the five treatments, namely, Bradyrhizobium spp. (Arachis) strain, Rhizobium leguminosarum strain, Tubatse strain, Sebayeng strain and untreated control, were laid-out in a randomised complete block design, with seven replications during the first season (Experiment 1) and with eight replications during the second season (Experiment 2). The seasonal interactions (Experiment 1 × Experiment 2) on plant and nutrient elements were not significant (P ≤ 0.05) and data for the two seasons were pooled (n = 75). Relative to untreated control, commercial (Bradyrhizobium and Rhizobium strain) and native strains (Tubatse and Sebayeng strain) significantly increased plant height by 31, 33, 44 and 40%, respectively, root length by 30, 41, 40 and 42%, respectively and dry shoot mass by 48,195 and 17%, respectively. Similarly, rhizobia strains significantly contributed to the increase in nitrogen assimilation by 7, 25 and 80%, respectively, protein synthesis by 13, 10, 24, 69%, respectively, and symbiotic efficiency by 31, 133, 292 and 82%, respectively. However, rhizobia inoculants had no significant effects on potassium and phosphorus in leaf tissues. In achieving Objective 3, in Mean Concentration Stimulation Point (MCSP) experiments, seven treatments, xxvi namely, 0, 2, 4, 8, 16, 32 and 64% for each phytonematicide, were arranged in a randomised complete block design (RCBD), with 8 replicates. In application interval experiments, treatments, based on “weeks-per-month-of-30 days” for M. javanica, which translated to 1, 2, 3 and 4 weeks, were arranged in a RCBD, with 10 replicates. Nemarioc-AL and Nemafric-BL phytonematicides had MCSP values of 3.43 and 4.03%, respectively, with the plant having high tolerance level to the products. The respective application interval of the two products for managing population densities of Meloidogyne species were 29 and 17 days. The dosage models for Nemarioc-AL and Nemafric-BL phytonematicides were 6.62 and 13.26%, respectively. In achieving Objective 5, the study used nine treatments designated as T1, T2, T3, T4, T5, T6, T7, T8 and T9, respectively, consisting of 1, 2, 3, 4, 5, 6, 7, 8 and 9 seedlings/hole of drip irrigation transplanted using a 3S planter under field conditions, arranged in randomised complete block design (RCBD) with 9 replications (n = 81) in two seasons. The NWP of total flavonoids, total tannin and total phenol exhibited positive quadratic relations in varied planting density suggesting that this cultural practices could be manipulated to improve NWP of cancer bush. In conclusion, the wild bacterial isolates, sampled from S. frutescens plant grown in the field, outperformed the commercial bacterial strains in enhancing the productivity of the test plants. The empirically established dosage model for Nemarioc-AL and Nemafric-BL phytonematicides could be used to control Meloidogyne species in cancer bush production. There is a need to further investigate the responses of the identified strains to the test phytonematicides. Findings of the study openend new frontiers in the development and commercialisation of the observed native bacterial strains for the cultivation of S. frutescens, which has excellent medicinal importance as a cure or management for cancer. / Agricultural Research Council-Universities Collaboration Centre, the National Research Foundation (NRF) and the Flemish Inter-University Council of Belgium