Identifying Edaphic Factors and Normalized Difference Vegetation Index Metrics Driving Wildlife Mortality From Anthrax in Kenya’s Wildlife Areas

Anthrax, an acute disease of homeotherms caused by soil-borne Bacillus anthracis is implicated in dramatic declines in wildlife mainly in sub-Saharan Africa. Anthrax outbreaks are often localized in space and time. Therefore, understanding predictors of the spatial and temporal occurrence of anthrax in wildlife areas is useful in supporting early warning and improved response and targeting measures to reduce the impact of epizootic risk on populations. Spatial localization of anthrax is hypothesized to be driven by edaphic factors, while the temporal outbreaks are thought to be driven by extreme weather events including temperature, humidity, rainfall, and drought. Here, we test the role of select edaphic factors and normalized difference vegetation index (NDVI) metrics driven by vegetation structure and climate variability on the spatial and temporal patterns of wildlife mortality from anthrax in key wildlife areas in Kenya over a 20-year period, from 2000 to 2019. There was a positive association between the number of anthrax outbreaks and the total number of months anthrax was reported during the study period and the nitrogen and organic carbon content of the soil in each wildlife area. The monthly occurrence (timing) of anthrax in Lake Nakuru (with the most intense outbreaks) was positively related to the previous month’s spatial heterogeneity in NDVI and monthly NDVI deviation from 20-year monthly means. Generalized linear models revealed that the number of months anthrax was reported in a year (intensity) was positively related to spatial heterogeneity in NDVI, total organic carbon and cation exchange capacity of the soil. These results, examined in the light of experimental studies on anthrax persistence and amplification in the soil enlighten on mechanisms by which these factors are driving anthrax outbreaks and spatial localization.

Deciphering Main Climate and Edaphic Components Driving Oat Adaptation to Mediterranean Environments

Oat, Avena sativa, is an important crop traditionally grown in cool-temperate regions. However, its cultivated area in the Mediterranean rim steadily increased during the last 20 years due to its good adaptation to a wide range of soils. Nevertheless, under Mediterranean cultivation conditions, oats have to face high temperatures and drought episodes that reduce its yield as compared with northern regions. Therefore, oat crop needs to be improved for adaptation to Mediterranean environments. In this work, we investigated the influence of climatic and edaphic variables on a collection of 709 Mediterranean landraces and cultivars growing under Mediterranean conditions. We performed genotype–environment interaction analysis using heritability-adjusted genotype plus genotype–environment biplot analyses to determine the best performing accessions. Further, their local adaptation to different environmental variables and the partial contribution of climate and edaphic factors to the different agronomic traits was determined through canonical correspondence, redundancy analysis, and variation partitioning. Here, we show that northern bred elite cultivars were not among the best performing accessions in Mediterranean environments, with several landraces outyielding these. While all the best performing cultivars had early flowering, this was not the case for all the best performing landraces, which showed different patterns of adaption to Mediterranean agroclimatic conditions. Thus, higher yielding landraces showed adaptation to moderate to low levels of rain during pre- and post-flowering periods and moderate to high temperature and radiation during post-flowering period. This analysis also highlights landraces adapted to more extreme environmental conditions. The study allowed the selection of oat genotypes adapted to different climate and edaphic factors, reducing undesired effect of environmental variables on agronomic traits and highlights the usefulness of variation partitioning for selecting genotypes adapted to specific climate and edaphic conditions.

The influence of edaphic factors on the vital state of large-flowered magnolia (Magnolia grandiflora L.). in the Nikitsky Botanical Gardens

The most widespread magnolia on the Southern coast of the Crimea and, in particular, in the Arboretum of the Nikitsky Botanical Gardens is the evergreen Magnolia grandiflora L., introduced in 1817. Currently, 28 generative specimens of Magnolia grandiflora of different ages grow in the Arboretum, including garden forms with different vital state. There are very few data on the relation of this species to soil conditions. For this reason, we have studied the influence of edaphic factors on the vital state of Magnolia grandiflora growing in the Arboretum of the Nikitsky Botanical Gardens. A number of limiting edaphic factors have been identified, the main of which is the high skeletal structure of the soil. The humus reserves in the soil have a positive effect on the vital state of trees. A high level of agricultural technology is the main method of improving the vital state of Magnolia grandiflora .

Diversity of Soil Dwelling Collembola in a Forest, Vegetable and Tea Ecosystems of Assam, India

Land use change has a great impact in determining the diversity patterns of soil fauna. Adoption of any land use pattern significantly affects the soil structure and its physico-chemical characteristics, which often leads to the loss of biodiversity. Considering the collembolans as the key organism in the indicator shopping basket of soil environment, the response of Collembola communities under three different land uses represented by forest, vegetable and tea ecosystems was studied. Collembolans were sampled at monthly intervals using Tullgren funnel and identified by standard taxonomic keys. Diversity analysis and soil chemo-edaphic factors were studied to establish the impact of different land uses on Collembola communities. Five genera of Collembola viz., Cyphoderus, Entomobrya, Isotoma, Folsomia and Hypogastrura were recorded from the forest ecosystem whereas Folsomia was completely absent in vegetable ecosystem and the tea ecosystem soil was devoid of both Folsomia and Hypogastrura. Seasonal diversity and density of Collembola were recorded to be higher in the forest ecosystem indicating the presence of relatively stable habitats as compared to vegetable and tea ecosystems showing relatively disturbed habitats. Correlation studies between different chemo-edaphic factors and collembolan population revealed that the moisture and organic carbon content of soil had significant positive correlation during all the four seasons in all the ecosystems studied. Higher adoption of mechanical and chemo-centric agriculture depletes the available resources of the soil and makes it less habitable and conducive for the growth and sustenance of collembolans in vegetable and tea ecosystem as compared to forest. Appropriate landscape planning, land management strategies and developing proper methods of land use practices may pave the way for the improvement of collembolan diversity at landscape level.

Characterization of Mulberry Genetic Resources for Multiple Traits

Mulberry plants have wide range of variations in characters in view of its adaptability to cross pollination with no inter-specific reproduction barrier rendering it a heterozygous species. Every plant being different from the other in natural population, this great diversity makes it difficult to gather information and carry out studies on effect of different edaphic factors on the expression of genotypic characters for adjudging the variations. In lieu of this known diversity for posterity, the collection of mulberry genotypes from diverse genetic sources, their conservation, evaluation and consequent documentation is of prime importance. In the present study, 69 mulberry accessions were characterized for morphology, anatomy, and reproductive parameters. Evaluation for propagation, growth and yield characters were also carried out. Based on multiple trait analysis, 14 top performing accessions viz., MI-0879, MI-0882, MI-0908, MI-0931, MI-0907, MI-0940, MI-0881, MI-0941, MI0892, MI-0913, MI-0937, MI-0934, MI-0865, MI-0886 were identified. These accessions could serve as resources for further evaluation aimed at trait-specific crop improvement.