The Effects of Invasive Plants on Biodiversity Across Spatial Scales

Although introduced plant species are often considered to be one of the most notable anthropogenic threats to biodiversity, their influence on biodiversity remains controversial. Some studies have shown large declines in biodiversity in plant-invaded areas, whereas others have noted that plant invasions are rarely implicated as the cause of species extinctions. This dissertation aims to synthesize this seemingly conflicting literature on the effects of invasive plants on biodiversity. The overarching hypothesis in this research is that the effect of invasive plant species on biodiversity is scale-dependent, and the discrepancy among studies can be explained by a difference in the scales of investigation at which these studies take place. In addition, the processes by which invasive plants influence community structure leads to slow, long-term extinction dynamics that mask likely future plant extinctions. In Chapter 1, I used a meta-analysis to examine the influence of invasive plants on plant biodiversity. The meta-analysis showed a negative relationship between the effect size of an invasive plant on biodiversity: i.e., species richness) and the spatial scale at which the data were collected. Next, in Chapter 1 and 2, I developed a framework that generated testable predictions about why invasive plants cause scale-dependent biodiversity loss. This framework linked the shifts in plant biodiversity to scale-dependence by using the species-area relationship. In Chapter 2, I tested the framework by conducting surveys of species-area relationships in habitats with and without invasive plants in three disparate ecosystems--a temperate forest, sub-tropical forest, and tropical forest. In all three ecosystems, species in invaded habitats accumulated faster with area than species in uninvaded habitats, revealing smaller effects of invasive plants on the loss of biodiversity with increasing spatial scale. Results showed that scale-dependent biodiversity loss was due to sampling effects: i.e., a loss of individuals), as well as larger negative effects on the abundance of common species compared to the abundance of rare species. In Chapter 3, I further investigated changes in community structure by exploring the demographic processes that result in differential effects on common versus rare native species in habitats invaded by Lonicera maackii: Caprifoliaceae) in Missouri, United States. The overall population growth of common species was consistently more negatively affected than that of rare species. This was due to larger declines in common species\u27 reproduction and greater sensitivity of their population growth to declines in the proportion of reproductive individuals. Finally, in Chapter 4, I established field and greenhouse experiments to test which abiotic conditions are altered by the presence of L. maackii. The results of these experiments showed that L. maackii significantly reduce light levels that reach the forest floor and that rare species tend to be more shade-tolerant than common species. This dissertation synthesizes literature on the effects of invasive plants on biodiversity and provides a framework for how to approach biodiversity loss and predict future extinctions in the context of species commonness and rarity. Overall, my research reconciles the differences observed among local and broad-scale effects of invasive plant species on biodiversity

PEPFAR Public Health Evaluation-Care and Support -Phase I Kenya

Phase 1, a survey of 120 care facilities in Kenya and Uganda, found that over 90% of facilities provided some level of clinical, psychological,and preventive care. Pain control was very limited with paracetamol often the only analgesic. In focus group discussions, patients appreciated free care and positive attitudes from staff, but said that services would be improved by more staff, shorter queues, and reliable drug supplies

PEPFAR Public Health Evaluation -Care and Support -Phase I Uganda

Phase 1, a survey of 120 care facilities in Kenya and Uganda, found that over 90% of facilities provided some level of clinical, psychological,and preventive care. Pain control was very limited with paracetamol often the only analgesic. In focus group discussions, patients appreciated free care and positive attitudes from staff, but said that services would be improved by more staff, shorter queues, and reliable drug supplies

PEPFAR Public Health Evaluation - Care and Support - Phase 2 Uganda

Phase 2 consisted of a longitudinal cohort study to measure patient-reported outcomes of care and support, a costing survey, and qualitative interviews to understand patient and carer experiences

PEPFAR Public Health Evaluation - Care and Support - Phase 2 Kenya

Phase 2 consisted of a longitudinal cohort study to measure patient-reported outcomes of care and support, a costing survey, and qualitative interviews to understand patient and carer experiences

Using statistics to model a social enterprise's path to scale

This work was carried out with the aid of a grant from Canada’s International Development Research Centre (IDRC), and with financial support from the Government of Canada, provided through Global Affairs Canada (GAC)Some non-profits and social sector organizations are recognizing the value of advanced data analysis and statistical modelling: collecting more detailed data can create more successful outcomes. This case study describes a pioneering social enterprise that used statistics to define key challenges toward financial sustainability and scale: “Farm Shop: A Social Enterprise in Search of Scale.” Farm Shop’s social franchise model works with local entrepreneurs to organize small shops in rural areas and sell agricultural and veterinary inputs, also providing referrals to services (soil testing, spraying, home delivery, artificial insemination, animal health care) that can enhance smallholder farmer productivity and incomes

Wellbeing among sub-Saharan African patients with advanced HIV and/or cancer: an international multicentred comparison study of two outcome measures

BACKGROUND: Despite the high mortality rates of HIV and cancer in sub-Saharan Africa, there are few outcome tools and no comparative data across conditions. This study aimed to measure multidimensional wellbeing among advanced HIV and/or cancer patients in three African countries, and determine the relationship between two validated outcome measures. METHODS: Cross-sectional self-reported data from palliative care populations in Kenya, Uganda and South Africa using FACIT-G+Pal and POS measures. RESULTS: Among 461 participants across all countries, subscale "social and family wellbeing" had highest (best) score. Significant country effect showed lower (worse) scores for Uganda on 3 FACIT G subscales: Physical, Social + family, and functional. In multiple regression, country and functional status accounted for 21% variance in FACIT-Pal. Worsening functional status was associated with poorer POS score. Kenyans had worse POS score, followed by Uganda and South Africa. Matrix of correlational coefficients revealed moderate correlation between the POS and FACIT-Pal core scale (0.60), the FACIT-G and POS (0.64), and FACIT-G+Pal with POS (0.66). CONCLUSIONS: The data reveal best status for family and social wellbeing, which may reflect the sample being from less individualistic societies. The tools appear to measure different constructs of wellbeing in palliative care, and reveal different levels of wellbeing between countries. Those with poorest physical function require greatest palliative and supportive care, and this does not appear to differ according to diagnosis