Multi-criteria evaluation of suitable sites for termite mounds construction in a tropical lowland

© 2019 Elsevier B.V. Termite mounds influence ecosystem heterogeneity and contribute to the stabilization of the system under global change. A number of environmental factors influence the distribution, height, diameter and designs of termite mounds but these factors are not only poorly understood, they cannot be extrapolated for everywhere. In this study, we employed a ground based survey and Geographical Information System (GIS) technique to map 156 km 2 study area in Keffi, Nigeria. The aims were to (1) estimate the density and area covered by termite mounds, (2) sample and identify species types and how they are distributed, and (3) use five environmental factors (elevation, geology, surface water drainage, land use/land cover and static water level) to model suitable sites for mounds construction. A total of 361 mounds were mapped representing a density of about 0.8 mounds ha −1 and covering only about 0.31% of the studied area. Next, the effect of the five chosen environmental factors on the geographic distribution, life status, height and diameter of mounds and species diversity were analysed and their relationships plotted in pairwise comparison matrices using the Saaty's Analytical Hierarchy Process. Normalized rates for classes in each factor and corresponding weights were computed and aggregated using the Weighted Linear Combination method. The result depicted that moderate to low elevation (270–330 m amsl), rock cover types that are more susceptible to weathering (schist), cultivated areas and shallow water table zones are most favourable for termites to build mounds. The result obtained in this study shows a promising correlation between the environmental factors and termite mounds distribution. The proposed model can easily be replicated in a different but similar multi-land use and rock cover types

Patterns of variation in reproductive parameters in Eurasian lynx (Lynx lynx)

Detailed knowledge of the variation in demographic rates is central for our ability to understand the evolution of life history strategies and population dynamics, and to plan for the conservation of endangered species. We studied variation in reproductive output of 61 radio-collared Eurasian lynx females in four Scandinavian study sites spanning a total of 223 lynx-years. Specifically, we examined how the breeding proportion and litter size varied among study areas and age classes (2-year-old vs. >2-year-old females). In general, the breeding proportion varied between age classes and study sites, whereas we did not detect such variation in litter size. The lack of differences in litter sizes among age classes is at odds with most findings in large mammals, and we argue that this is because the level of prenatal investment is relatively low in felids compared to their substantial levels of postnatal care

Confronting Uncertainty in Wildlife Management: Performance of Grizzly Bear Management

Scientific management of wildlife requires confronting the complexities of natural and social systems. Uncertainty poses a central problem. Whereas the importance of considering uncertainty has been widely discussed, studies of the effects of unaddressed uncertainty on real management systems have been rare. We examined the effects of outcome uncertainty and components of biological uncertainty on hunt management performance, illustrated with grizzly bears (Ursus arctos horribilis) in British Columbia, Canada. We found that both forms of uncertainty can have serious impacts on management performance. Outcome uncertainty alone – discrepancy between expected and realized mortality levels – led to excess mortality in 19% of cases (population-years) examined. Accounting for uncertainty around estimated biological parameters (i.e., biological uncertainty) revealed that excess mortality might have occurred in up to 70% of cases. We offer a general method for identifying targets for exploited species that incorporates uncertainty and maintains the probability of exceeding mortality limits below specified thresholds. Setting targets in our focal system using this method at thresholds of 25% and 5% probability of overmortality would require average target mortality reductions of 47% and 81%, respectively. Application of our transparent and generalizable framework to this or other systems could improve management performance in the presence of uncertainty. &nbsp

Evapotranspiração e coeficientes de cultivo da beterraba orgânica sob cobertura morta de leguminosa e gramínea.

As práticas agrícolas que maximizam a produtividade e o uso da água são de vital importância para a agricultura. Assim, foram testados três tipos de manejo do solo com objetivo de determinar a evapotranspiração (ETc) e os coeficientes de cultivo (kc) da beterraba. Os tipos de manejo foram a utilização de coberturas mortas vegetais, denominadas capim cameroon (Pennisetum purpureum), gliricídia (Gliricidia sepium) e solo sem cobertura morta em área experimental do SIPA (Sistema Integrado de Produção Orgânica) localizado em Seropédica, Brasil. A lâmina de irrigação foi estimada com base no balanço de água no solo, cujo monitoramento foi realizado com a técnica da TDR. As ETc acumuladas para a cultura da beterraba foram 59,41; 55,31 e 119,62 mm, respectivamente, para capim cameroon, gliricídia e solo sem cobertura morta. A evapotranspiração de referência (ETo) foi obtida por meio do modelo de Penamn-Monteith. Os valores médios de kc obtidos para as fases inicial, média e final de desenvolvimento foram de 0,39; 0,42 e 1,02; 0,79; 0,76 e 1,18; e 0,56; 0,61 e 0,84, respectivamente, para capim cameroon, gliricídia e solo sem cobertura morta. O uso da cobertura do solo com gramínea ou leguminosa minimizou de forma expressiva a demanda hídrica da cultura da beterraba (Beta vulgaris)

UHPLC-ESI/TOFMS Determination of Salicylate-like Phenolic Gycosides in Populus tremula Leaves

Associations of salicylate-like phenolic glycosides (PGs) with biological activity have been reported in Salix and Populus trees, but only for a few compounds, and in relation to a limited number of herbivores. By considering the full diversity of PGs, we may improve our ability to recognize genotypes or chemotype groups and enhance our understanding of their ecological function. Here, we present a fast and efficient general method for salicylate determination in leaves of Eurasian aspen that uses ultra-high performance liquid chromatography-electrospray ionization/time-of-flight mass spectrometry (UHPLC-ESI/TOFMS). The time required for the liquid chromatography separations was 13.5 min per sample, compared to around 60 min per sample for most HPLC protocols. In leaf samples from identical P. tremula genotypes with diverse propagation and treatment histories, we identified nine PGs. We found the compound-specific mass chromatograms to be more informative than the UV-visible chromatograms for compound identification and when quantitating samples with large variability in PG content. Signature compounds previously reported for P. tremoloides (tremulacin, tremuloidin, salicin, and salicortin) always were present, and five PGs (2'-O-cinnamoyl-salicortin, 2'-O-acetyl-salicortin, 2'-O-acetyl-salicin, acetyl-tremulacin, and salicyloyl-salicin) were detected for the first time in P. tremula. By using information about the formic acid adduct that appeared for PGs in the LTQ-Orbitrap MS environment, novel compounds like acetyl-tremulacin could be tentatively identified without the use of standards. The novel PGs were consistently either present in genotypes regardless of propagation and damage treatment or were not detectable. In some genotypes, concentrations of 2'-O-acetyl-salicortin and 2'-O-cinnamoyl-salicortin were similar to levels of biologically active PGs in other Salicaceous trees. Our study suggests that we may expect a wide variation in PG content in aspen populations which is of interest both for studies of interactions with herbivores and for mapping population structure

The potential impacts of changes in bear hunting policy for hunting organisations in Croatia

The brown bear (Ursus arctos) in Croatia is currently being managed through trophy hunting, with quotas allocated to local hunting organisations. Human-bear conflict is present at a low level, but any losses are compensated by the hunting organisations that benefit from bear hunting. Attitudes towards bears are generally positive, and the bear population appears stable, or even increasing. Croatia's current bear hunting policy relies upon both the ecological sustainability of the quotas and the economic sustainability of the hunting organisations. To address the first of these pillars of current policy, we used a two-sex matrix model of the bear population to investigate the biological sustainability of current hunting levels. The model suggests that if the annual allocated quota were fully realised, the population would suffer a considerable decrease over 10 years. A likely explanation for the mismatch between this result and the observed stability of the population is that the bear population size is underestimated. To address the second pillar, we quantified the current structure, costs and benefits of bear hunting to hunting organisations through an interview survey with hunting managers. We found that bear hunting is a substantial component of hunting organisations' income, supporting the other activities of the organisation. Croatia's recent accession to the EU will require changes in their bear management system, potentially stopping bear trophy hunting. Therefore, we assessed the changes in hunting organisations' budgets in the absence of bear hunting. Our results demonstrate that a loss of bear trophy hunting would result in a substantial loss of income to the hunting organisations. Moving bear hunting and compensation mechanisms from local management and responsibility to a more centralised system without trophy hunting, as suggested by EU legislation, will lead to considerable uncertainties. These include how to make centralised decisions on population targets and offtake levels for population control, given the uncertainty around population estimates, and on compensation payments given the loss of the current system which relies heavily on local income from trophy hunting, local relationships and informal monetary and non-monetary compensation

Understanding Attitudes Towards Native Wildlife and Biodiversity in the UK: The Role of Zoos

International audienc