Effect of mixing cereal and legume straws on yield of grey oyster mushroom under controlled conditions

In Zimbabwe, yield of oyster mushroom ( Pleurotus ostreatus ) grown on sole substrates of maize or sorghum straw is low, <75% biological efficiency translating to less than a kilogramme of fresh mushroom per kg of dry substrate. This study aimed at determining the effect of mixing sorghum or maize straw with various proportions of bean straw, on the yield of grey oyster mushroom. Maize and sorghum straws were singly mixed with 0, 20, 40, 60, 80 and 100% bean straw, followed by a spawning rate of 5%. Eighteen days after incubation in a dark room, bags were hanged in a mushroom growing house with controlled temperatures (25-26oC). Mixing bean with maize straw had a significantly higher oyster mushroom yield (1, 229 g) than with sorghum straw (1,138 g); leading to biological efficiency of 83 and 74%, for maize straw and sorghum straw, respectively. Yield and biological efficiency decreased from 1,357 to 977 g plot-1 and 97 to 61%, respectively, when the proportion of bean straw was increased from 0-100%; while number of days to second and third harvest increased. There were significant interactions (P<0.05) for the number of pins, days to second and third harvest, between maize or sorghum straw with bean straw. Maize straw gave better performance with high percentages of bean straw than sorghum straw. Results showed that maize straw mixed with 20% bean straw produced better yield of grey oyster mushroom.Au Zimbabwe, le rendement de pleurotes ( Pleurotus ostreatus ) produites sur les substrats des pailles du ma\uefs ou du sorgho est faible, < 75% de l\u2019efficience biologique traduisant \ue0 moins d\u2019un kg des champignons frais par kg du poids sec du substrat. Cette \ue9tude visait \ue0 d\ue9terminerl\u2019effet du m\ue9lange des pailles du ma\uefs et du sorgho avec diverses proportions de la paille du haricot, sur le rendement du pleurote gris. Les pailles du ma\uefset du sorgho ont \ue9t\ue9 singuli\ue8rementm\ue9lang\ue9es avec 0, 20, 60, 80 et 100% de la paille du haricot, suivie par un taux de 5% de myc\ue9lium. Dix-huit jours apr\ue8s incubation dans une chambre noire, les sacs ont \ue9t\ue9 suspendus dans une chambre de croissance de champignon avec des temp\ue9ratures contr\uf4l\ue9es (25-26oC).Le m\ue9lange de la paille du haricot avec la paille du ma\uefs a eu un rendement significativement plus \ue9lev\ue9 du pleurote (1 229 g) qu\u2019avec la paille du sorgho (1 138 g)\ua0; entrainant une efficience biologique de 83 et 74%, pour la paille du ma\uefs et du sorgho, respectivement. Le rendement et l\u2019efficience biologique ont d\ue9cru du 1 357 \ue0 977 g plot-1 et 97 \ue0 61%,respectivement, quand la proportion de la paille du haricot a augment\ue9 de 0-100%\ua0; alors que le nombre de jours \ue0 la deuxi\ue8me et troisi\ue8me r\ue9colte a augment\ue9. Il y a eud\u2019interactions significatives (P<0.05) pour le nombre de broches, le nombre de jours \ue0 la deuxi\ue8me et troisi\ue8me r\ue9colte, entre la paille du ma\uefs etdu sorgho avec celle du haricot. La paille du ma\uefs a donn\ue9 de meilleures performances avec des pourcentages \ue9lev\ue9s de la paille du haricot que celle du sorgho. Les r\ue9sultats ont montr\ue9 que la paille du ma\uefs m\ue9lang\ue9e avec 20% de la paille du haricot ont produit de meilleur rendement du pleurote gris

Are fission–fusion dynamics consistent among populations? A large‐scale study with Cape buffalo

Fission–fusion dynamics allow animals to manage costs and benefits of group living by adjusting group size. The degree of intraspecific variation in fission–fusion dynamics across the geographical range is poorly known. During 2008–2016, 38 adult female Cape buffalo were equipped with GPS collars in three populations located in different protected areas (Gonarezhou National Park and Hwange National Park, Zimbabwe; Kruger National Park, South Africa) to investigate the patterns and environmental drivers of fission–fusion dynamics among populations. We estimated home range overlap and fission and fusion events between Cape buffalo dyads. We investigated the temporal dynamics of both events at daily and seasonal scales and examined the influence of habitat and distance to water on event location. Fission–fusion dynamics were generally consistent across populations: Fission and fusion periods lasted on average between less than one day and three days. However, we found seasonal differences in the underlying patterns of fission and fusion, which point out the likely influence of resource availability and distribution in time on group dynamics: During the wet season, Cape buffalo split and associated more frequently and were in the same or in a different subgroup for shorter periods. Cape buffalo subgroups were more likely to merge than to split in open areas located near water, but overall vegetation and distance to water were very poor predictors of where fission and fusion events occurred. This study is one of the first to quantify fission–fusion dynamics in a single species across several populations with a common methodology, thus robustly questioning the behavioral flexibility of fission–fusion dynamics among environments

Towards utilization of water hyacinth for industrial products: A Review paper

Water hyacinth is a useful weed in the cleaning of water bodies loaded with industrial effluent but can become an environmental problem if its growth is not controlled. Water hyacinth is a potential raw material of several industrial applications. However chemical structure of the lignocellulosic hyacinth biomass has to be broken down first in order to obtain fermentable sugars. Wood rotting fungi has been known to delignify plant biomass. Wood rotting fungi secrete extracellular enzymes including lignin peroxidase, manganese peroxidase and laccase that are important industrial enzymes with numerous biotechnological applications in bio-fuel, food, brewery and wine, animal feed, textile and laundry, pulp and paper and agricultural industries. This paper reviews the potential use of white rot fungi's (Pleurotus sajor caju, Pleurotus ostreatus and Lentinus edodes) extracellular enzymes to biodegrade water hyacinth biomass.Keywords: water hyacinth, lignocelluloses, wood rotting fungi, extracellular enzyme

Tracking data highlight the importance of human-induced mortality for large migratory birds at a flyway scale

Human-induced direct mortality affects huge numbers of birds each year, threatening hundreds of species worldwide. Tracking technologies can be an important tool to investigate temporal and spatial patterns of bird mortality as well as their drivers. We compiled 1704 mortality records from tracking studies across the African-Eurasian flyway for 45 species, including raptors, storks, and cranes, covering the period from 2003 to 2021. Our results show a higher frequency of human-induced causes of mortality than natural causes across taxonomic groups, geographical areas, and age classes. Moreover, we found that the frequency of human-induced mortality remained stable over the study period. From the human-induced mortality events with a known cause (n = 637), three main causes were identified: electrocution (40.5 %), illegal killing (21.7 %), and poisoning (16.3 %). Additionally, combined energy infrastructure-related mortality (i.e., electrocution, power line collision, and wind-farm collision) represented 49 % of all human-induced mortality events. Using a random forest model, the main predictors of human-induced mortality were found to be taxonomic group, geographic location (latitude and longitude), and human footprint index value at the location of mortality. Despite conservation efforts, human drivers of bird mortality in the African-Eurasian flyway do not appear to have declined over the last 15 years for the studied group of species. Results suggest that stronger conservation actions to address these threats across the flyway can reduce their impacts on species. In particular, projected future development of energy infrastructure is a representative example where application of planning, operation, and mitigation measures can enhance bird conservation.publishedVersio

Missing in action: Species competition is a neglected predictor variable in species distribution modelling

The central role of species competition in shaping community structure in ecosystems is well appreciated amongst ecologists. However species competition is a consistently missing variable in Species Distribution Modelling (SDM). This study presents results of our attempt to incorporate species competition in SDMs. We used a suit of predictor variables including Soil Adjusted Vegetation Index (SAVI), as well as distance from roads, settlements and water, fire frequency and distance from the nearest herbivore sighting (of selected herbivores) to model individual habitat preferences of five grazer species (buffalo, warthog, waterbuck, wildebeest and zebra) with the Ensemble SDM algorithm for Gonarezhou National Park, Zimbabwe. Our results showed that distance from the nearest animal sighting (a proxy for competition among grazers) was the best predictor of the potential distribution of buffalo, wildebeest and zebra but the second best predictor for warthog and waterbuck. Our findings provide evidence to that competition is an important predictor of grazer species' potential distribution. These findings suggest that species distribution modelling that neglects species competition may be inadequate in explaining the potential distribution of species. Therefore our findings encourage the inclusion of competition in SDM as well as potentially igniting discussions that may lead to improving the predictive power of future SDM efforts