Multi-empirical investigations on the population genetic structure, ecological niche, and regeneration of Ivesia webberi with conservation implications

Ecosystems often contain a few cosmopolitan species and a large number of rare species. Despite their relative low abundance and biomass, rare species support the multifunctionality and resilience of ecosystems. Therefore, empirical studies on rare and range-restricted species can increase our understanding of eco-evolutionary underpinnings of species and ecosystem persistence, and generate sufficient knowledge to design effective conservation programs. These research studies can also benefit conservation programs for rare and range-restricted species, which are often prioritized. This research focuses on Ivesia webberi, a federally threatened perennial forb and the vegetative communities that harbor the species. Specifically, empirical studies investigated the following: (1) species-environment relationship of I. webberi using iterative and multi-year ecological niche modeling with complementary model-guided sampling, to describe and predict suitable habitats; (2) the relationship between soil seed bank and aboveground vegetation in plant communities where I. webberi is found, to understand the regeneration niche of I. webberi and assess ecological resilience of the vegetative communities; (3) genetic diversity, structure, and functional connectivity among I. webberi populations in order to characterize genetic resources and therefore evolutionary potential; (4) the relationships between genome size variation and bioclimatic variables within I. webberi and among Ivesia taxa; and (5) seed viability of I. webberi, including spatiotemporal variability and storage behavior.Findings from the 5-year iterative niche modeling study resulted in the discovery of seven novel populations, an expansion of the known species distribution range, and identification of important environmental drivers of the ecological niche of I. webberi. Native species richness was higher in aboveground vegetation in the sampled sites where I. webberi occurs while the soil seed bank is dominated by invasive annual grasses. This resulted in low floristic similarity between the aboveground vegetation and the soil seed bank, and highlights the importance of seeding with native plants and control of invasive plant species to maintain the ecological legacies of these sites in the Great Basin Desert. Genetic diversity is relatively low across I. webberi populations and exhibited significant spatial genetic structure; functional connectivity was influenced by synergistic effects of geographic distance and landscape features. However, I. webberi exhibits a significant temporal, not geographical, variation in seed viability, and seed viability potentially reduces with storage time suggesting a recalcitrant behavior. Seed viability can be reliably estimated and monitored using non-destructive x-ray imagery and multispectral imaging techniques. An 8-fold variation in genome size of 31 Ivesia taxa was observed, ranging from 0.73 pg/2C in I. baileyi var. beneolens to 5.91 pg/2C in I. lycopodioides ssp. megalopetala. This genome size variation significantly correlated with actual evapotranspiration and seed size. Inference from genome size suggest that all sampled Ivesia are diploid with 28 chromosomes. Similar significant correlations between intraspecific genome size variation in I. webberi and evapotranspiration and seed size were observed; genome size was larger in I. webberi populations closer to the species’ range center and smaller towards the margin. Relatively small genome sizes and their correlations with functional trait and energy availability indicate that genome size has adaptive significance for these desert-adapted species. Overall, the findings of these studies have advanced scientific knowledge on the eco-evolutionary processes in a range-restricted plant species in the Great Basin Desert, and provide useful information to design effective conservation programs

In vitro propagation of Tacca leontopetaloides (L.) Kuntze in Nigeria

This study was carried out to assess the propagation of Tacca leontopetaloides (Taccaceae) in vitro using seed embryos. The seeds were cultured on Murashige & Skoog basal media augmented with various concentrations of single or combined growth hormones to obtain a suitable protocol for plantlet regeneration. Seed embryo germination of 57% was obtained, as against 20% for germination under conventional sowing. The best shoot proliferation was obtained using media fortified with 0.1 mg/L 6-benzyl amino purine and 0.01 mg/L naphthalene acetic acid, while the best rooting was obtained with MS media supplemented with 0.1 mg/L indole butyric acid. Callus formation was not observed on plantlets in vitro, indicating much easier and less challenging in vitro plant propagation.Keywords: tissue culture, micro-propagation, regeneration, recalcitranc

VOLUME PREDICTION FOR MILICIA EXCELSA (WELW C.C. BERG.) TREES IN SELECTED INSTITUTIONS IN IBADAN, OYO STATE, NIGERIA

The study develops equations for the prediction of stem volume of Milicia excelsa  (Welw C.C. Berg.) in some selected institutions in Ibadan, Oyo State, Nigeria. Sequel to the relationship between stem volume (sv), diameter at base (db) and  at breast height (dbh) from enumeration of 61 trees in selected institutions, equations were developed for estimating tree volumes of M. excelsa. Of all the equations developed, logarithmic for volume was the best fit equation containing the db and dbh as the predictors. The equation is lnSV = 1.5924 + 1.4915lndb + 0.8600lndbh with coefficient of determination (R2) and standard error of estimate being 0.9011 and SEE = 0.3485 respectively. Residual analysis revealed that the assumption of independence of residuals is valid, and there is no evidence of an outlier. Validation of the equation was done by testing for significant difference between the predicted stem volume (PSV) and observed stem volume (OSV). The study showed that stem volume of M. excelsa can be predicted from db and dbh by using this equation with reasonable precision. The prediction equation developed in this work would be very useful and applicable where tree dimensions such as diameter at middle and top as well as the height of M. excelsa is difficult to assess and there is need to reduce the cost of inventory of such species.Â

Socio-Economic Benefits of Iroko Trees (Milicia excelsa Welw C.C. Berg) in Ibadan Metropolis, Oyo State, Nigeria

A complete survey of Iroko trees in Ibadan metropolis was carried out with the view to determining their distribution and status. The entire of Ibadan City was considered for the study. The city was divided into sections and a reconnaissance survey was conducted to confirm existence of the tree species within each of the section. Direct observation of the already identified Iroko trees was then carried out during the actual data collection stage of the study. Permissions were sought before data collection was carried out on the identified trees. A total of 62 Iroko trees were surveyed; out of these, 33 (53.2%) stands were accessible while the remaining 29 stands (46.8%) were inaccessible. Many of the trees that could not be accessed were a result of restriction into the location where they exist. The most frequently observed benefit obtained trees are shade from direct sunlight and cool breeze it creates. Other uses of trees include peeling of the tree bark and used in preparation of local medicine, fetish activities on and around the tree, and use of the fallen branches as firewood. There is urgent need for appropriate protection strategies of these remaining indigenous tree species where they exist. Keywords: Milicia excelsa, endangered species, urban forest, bark slashing, medicines, restriction, Ibada

Morphological and anatomical studies on Tacca leontopetaloides (L.) Kuntze (Taccaceae) in Nigeria

Tacca leontopetaloides is the only species in the genus Tacca naturally distributed in the Guinea savannah and dry rainforest regions in Nigeria. The study was conducted to contribute to scientific knowledge on the macro-morphological and anatomical features of the plant collected from 4 locations (Akoko, Eruwa, Bazza and Ile-Ife) across the Nigeria and to determine the effect of environmental factors on its anatomy. Leaf epidermal peel of the 4 samples, leaf and stem Transverse Sections (T.S) and stem Tangential Longitudinal Section (T.L.S) and Radial Longitudinal Section (R.L.S) as well as stem fibres were prepared and studied. A wide range of similarities and differences were noted in the anatomical features of the 4 samples studied. The similarities include, but not limited to stomata being anomocytic, epidermis hypostomatic, cuticle single-layered and striated, vascular bundles conjointed collateral, epidermis undulating, stem rays uniserrate and procumbent, stem fibres non-septate and non-storeyed. Wide range of variations are noted in stomata density and measurements, epidermal cell density, guard cell measurements, cuticle thickness, vascular bundle arrangement, shapes of parenchyma and sclerenchyma cells and many other anatomical features. The variations observed among the samples studies were attributed to the prevailing environmental factors in each collection site.Morphological and anatomical studies on Tacca leontopetaloides (L.) Kuntze (Taccaceae) in Nigeri

Assessment of nutritional and sensory qualities of whole grains cookies formulated from vegetables and mushrooms

Malnutrition and obesity keeps increasing in the developing countries alongside, the burden of diet-related diseases, therefore, regular food is expected to be functional by providing additional health benefits; other than basic nutritional needs. In this study, 10, 25 and 50 % of two edible mushrooms namely; Termitomyces robustus and Lentinus squarrosulus and four vegetables; Basella alba, Launea taraxacifolia, Senecio biafrae, and Crassocephalum ruben were used to substitute whole grain flours of wheat, millet, guinea corn and yellow corn, separately, in formulation of cookies, with the aim of improving the nutritional properties and health benefit potential of the cookies. Proximate composition of the cereal flours were in the range of 7.27±0.06 -11.56 ±0.20% (moisture), 0.52±0.05 - 2.51±0.26 % (Ash), 8.48a±0.44- 14.97d±0.10% (protein), 8.72a±0.86- 12.35e±0.13 (fat), 0.19a±0.05 - 1.91e±0.03 % (fibre) and 63.78±0.43- 68.84b±0.56 % (carbohydrate). The nutritional and sensory qualities of representative cookies from each formulation were determined. Generally, supplementation with the vegetables and mushrooms had positive effect on the mineral, vitamins and proximate compositions, which is an indication of good nutritional quality; also the non-wheat flours compared favourably with the wheat flour nutritional-wise. Although, there was significant difference in sensory quality and acceptability of the non-wheat and wheat cookies, the results show that it is possible to use the named mushrooms, vegetables and grains to partially (≤ 10 %) substitute for wheat flour in the production of flour -based food systems with acceptable physical characteristics

Socio-economic contributions of an indigenous tree in urban areas of southwest Nigeria

Indigenous trees have been discovered to be disappearing from urban areas at alarming rates, and the contributions of the existing trees are not adequately documented. Milicia excelsa is an indigenous trees species in tropical Africa and popularly known as Iroko. Due to extensive exploitation for wood production and other socio-economic activities, the tree species is classified as threatened and relics could only be found in a few locations. A survey of the trees in the city of Ibadan was therefore carried out to determine their distribution as well as their socio-economic contributions to the urban people. A semi-structured questionnaire was administered to the people living close to the trees or working in the locations where the trees are sighted to determine the socio-economic benefits. A total of 65 trees (0.14 trees/km2) of M. excelsa were sighted. As observed in the city, the benefits of the tree species were categorized as: environmental, medicinal, economic, spiritual and ecological services. Provision of shade that creates a ‘microclimatic environment’ in the form of cooling effects from the heat of the day was mentioned by about 95% of the respondents as the major benefit obtained from the trees. A strategy for the conservation of the trees as urban trees and their protection against damage to life and property are considered imperative. There is also a need for an appropriate policy that protects indiscriminate felling of indigenous trees in the city and constant monitoring of the trees’ status for any sign of weakness.http://adonisandabbey.com/show_journal1.php?list_journals=14am2014gv201

The manifold costs of being a non-native English speaker in science

The use of English as the common language of science represents a major impediment to maximising the contribution of non-native English speakers to science. Yet few studies have quantified the consequences of language barriers on the career development of researchers who are non-native English speakers. By surveying 908 researchers in environmental sciences, this study estimates and compares the amount of effort required to conduct scientific activities in English between researchers from different countries and, thus, different linguistic and economic backgrounds. Our survey demonstrates that non-native English speakers, especially early in their careers, spend more effort than native English speakers in conducting scientific activities, from reading and writing papers and preparing presentations in English, to disseminating research in multiple languages. Language barriers can also cause them not to attend, or give oral presentations at, international conferences conducted in English. We urge scientific communities to recognise and tackle these disadvantages to release the untapped potential of non-native English speakers in science. This study also proposes potential solutions that can be implemented today by individuals, institutions, journals, funders, and conferences.This work was funded by the Australian Research Council Future Fellowship FT180100354 (TA), The University of Queensland strategic funding (TA), and the German Research Foundation (DFG-FZT 118, 202548816) (SC). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe

Sickness and agricultural productivity: evidence from arable-crop farmers in Southwest, Nigeria

Literature argued that investments in the health programs for labour to prevent sickness in farming operations enhances agricultural productivity. This paper estimates a stochastic production function using 240 primary data to analyze the relationship between farmers’ dietary-pattern, health-status and agricultural production efficiency. Study indicated that workdays lost to sickness influenced poor farm-income and productivity and the effect is considerable. Sound dietary-patterns and health status enhances human productivity and farm-profit levels. Moreover, the incapacitating effects of sickness on farm-labour leads to diminishing effects on farmer’s efficiency level. Average value of technical efficiency per-unit of input tends to be higher for healthy farmers than for those affected by sickness. About 79.1% of the respondents spent 85.6% of their farm-proceeds on medical expenses, while 66.8% of the respondents were unable to meet medical expenses from farm-proceeds. Hence, expenditures on health upsets affect the availability of disposable cash income as household financial resources are diverted to pay for medical treatment. Thus, deny farmers inability to procure agricultural inputs that can improve agricultural productivity. Regression results confirm the negative effect of health barriers on farmers’ agricultural production-efficiency. Results suggest that one workday lost to sickness increase farmers’ inefficiency by 0.4%