Post-fire ephemerals and spinifex-fuelled fires: a decision model for bilby habitat management in the Tanami Desert, Australia

2007 ◽  
Vol 16 (6) ◽  
pp. 741 ◽  
Author(s):  
Richard Southgate ◽  
Susan Carthew
Keyword(s):  
Habitat Suitability ◽  
Decision Model ◽  
Habitat Management ◽  
Fire History ◽  
Spatial Databases ◽  
Ground Cover ◽  
Weather Conditions ◽  
Early Summer ◽  
Annual Rainfall ◽  
Factors Affecting

Seed from post-fire ephemeral plants like Yakirra australiense can form an important component of the diet of the bilby, a threatened arid-dwelling bandicoot. An investigation was conducted to determine the factors affecting the production of Yakirra and fire reoccurrence in the Tanami Desert. A simple decision model was produced to assist managers decide where and when to burn and what to expect regarding Yakirra australiense growth following fire and rainfall. The information used in the model may be derived from existing spatial databases that document rainfall and fire history and could be used to map broad-scale temporal change in total vegetation cover and components of habitat suitability for the bilby. The season and magnitude of rainfall and time-since-fire were the most important variables in the production of Yakirra seed. Rainfall >300 mm within a 2-month period of intense-complete burns could result in >5% Yakirra cover, and >100 mm was required for >1% cover. Negligible Yakirra cover occurred in adjacent long-unburnt plots. Total ground cover and spinifex cover varied substantially in relation to mean annual rainfall, but not in relation to substrate type. Long-unburnt spinifex cover was mostly too sparse to carry a fire in the southern part of the Tanami and the growth of non-spinifex vegetation would be necessary to boost fuel loads sufficiently to carry a fire. Generally, more than 41% cover was required to carry a fire but this was also dependent on weather conditions. Managers should aim to burn in late spring or early summer to improve Yakirra production. Fire management to enhance habitat suitability for the bilby would be of most benefit in the northern part of the Tanami Desert where growth rate of vegetation is greater and there is little existing fire age heterogeneity.

scholarly journals Factors affecting waterfowl hunting and harvest at the Evros delta, Greece

2020 ◽  
Vol 150 ◽  
Author(s):  
Savas Kazantzidis ◽  
Christos Astaras ◽  
Ioakim Vasiliadis ◽  
Eleni Makrygianni ◽  
Vassilis Ilias ◽  
...  
Keyword(s):  
Habitat Management ◽  
Weather Conditions ◽  
Abundant Species ◽  
Protected Species ◽  
Factors Affecting ◽  
Management Actions ◽  
Hunting Activity ◽  
Wintering Waterfowl ◽  
Waterfowl Hunting ◽  
The Relationship

The Evros delta is one of the most important wetlands for wintering waterfowl in Greece and the most popular among waterfowl hunters. This study addresses hunting activity and harvest while also investigating the relationship between weather conditions and hunting activity to suggest ways of improving waterfowl management. We counted wintering waterfowl and hunter numbers, and conducted hunter bag surveys during December–February over four hunting seasons. We calculated a 10-day goose and duck Preferential Shooting Index (PSI), which is the ratio of observed number of shot birds to the number of birds expected to have been shot if the birds were shot in proportion to their availability. Common Teal, Mallard and Greater White-fronted Goose were the most abundant species both in the field and in hunter bags. The mean number of hunters/day was 99.9, with each one shooting on average 2.5 birds/day. The overall waterfowl harvested accounted for 1.3% of the total waterfowl population. For geese this proportion was six times higher (8.7%), while for ducks alone and protected species was 1.2% and 1.4% respectively. Geese were shot more often than expected (PSI 6.55), while ducks and protected species were shot according to their availability (PSI 0.86 and 1.02, respectively). Wind speed, precipitation and geese number in the field were the best predictors of overall harvest and number of hunters. To reduce goose overshooting and the probability of protected species being accidentally shot, we suggest habitat management actions for the geese feeding areas and hunters’ awareness raising.

scholarly journals DYNAMICS OF BIODIVERSITY OF NECTAR-BEARING RESOURCES IN THE STRUCTURE OF BIRCH FORESTS

2020 ◽  
Vol 9 (4) ◽  
pp. 73-81
Author(s):  
Irina Samsonova ◽  
Van Do ◽  
Thi Nguen ◽  
Petr Sidarenko Petr
Keyword(s):  
Species Diversity ◽  
Species Composition ◽  
Similarity Index ◽  
Ground Cover ◽  
Weather Conditions ◽  
Diversity Indices ◽  
Forest Edge ◽  
Leningrad Region ◽  
Factors Affecting ◽  
Birch Forests

The Northwest region of Russia has a rich forage base for bees. Due to unstable weather conditions, the use of natural honey resources is complicated. The aim of the research was to determine the dynamics of biodiversity of nectar-bearing resources in the structure of birch forests. Registration sites in the birch forests of blueberry, myrtillus and myrtillus grass and under the canopy of the forest stand and at the forest edges of the Kirov Educational Experimental and Kirish Forestries of the Leningrad Region have been laid for accounting. Circular reference plots with an area of 10 m2 and a radius of 178.5 cm were used when accounting for the vegetation of the lower tier. When calculating species diversity indices, species richness indices used in biocenological studies were used. The research results have showed that the factors affecting the species composition of honey plants are the light regime under the stand canopy and biological characteristics of honey plants. The composition and number of species depends on the type of forest. According to Simpson and Margalef, grass birch is distinguished by the species diversity and richness of species. Sorrel birch forest is distinguished by the best forest ecosystem with honey species. When comparing the Sørensen coefficient for sorrel birch and grass birch, it does not exceed 0.5, which indicates the similarity of species in the experimental plots. 200 the Jacquard similarity index indicates that 25-50 % of species in the forest phytocenoses of birch forests are the same. The magnitude of the variegation of living ground cover is high in the forest edge and low in myrtillus birch wood. Thus, the species composition of the melliferous flora of the studied forest types is variable in its structure and composition

scholarly journals Rain Erosion Maps for Wind Turbines Based on Geographical Locations: A Case Study in Ireland and Britain

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
K. Pugh ◽  
M. M. Stack
Keyword(s):  
Wind Turbine ◽  
Western Europe ◽  
Meteorological Data ◽  
Turbine Blades ◽  
Weather Conditions ◽  
Annual Rainfall ◽  
Wind Turbine Blades ◽  
Weather Patterns ◽  
The Uk

AbstractErosion rates of wind turbine blades are not constant, and they depend on many external factors including meteorological differences relating to global weather patterns. In order to track the degradation of the turbine blades, it is important to analyse the distribution and change in weather conditions across the country. This case study addresses rainfall in Western Europe using the UK and Ireland data to create a relationship between the erosion rate of wind turbine blades and rainfall for both countries. In order to match the appropriate erosion data to the meteorological data, 2 months of the annual rainfall were chosen, and the differences were analysed. The month of highest rain, January and month of least rain, May were selected for the study. The two variables were then combined with other data including hailstorm events and locations of wind turbine farms to create a general overview of erosion with relation to wind turbine blades.

scholarly journals Vessel Multi-Parametric Collision Avoidance Decision Model: Fuzzy Approach

2021 ◽  
Vol 9 (1) ◽  
pp. 49
Author(s):  
Tanja Brcko ◽  
Andrej Androjna ◽  
Jure Srše ◽  
Renata Boć
Keyword(s):  
Fuzzy Logic ◽  
Collision Avoidance ◽  
Decision Model ◽  
Fuzzy Inference ◽  
Weather Conditions ◽  
Target Vessel ◽  
Planning Tool ◽  
Inference System ◽  
International Regulations ◽  
Input Variables

The application of fuzzy logic is an effective approach to a variety of circumstances, including solutions to maritime anti-collision problems. The article presents an upgrade of the radar navigation system, in particular, its collision avoidance planning tool, using a decision model that combines dynamic parameters into one decision—the collision avoidance course. In this paper, a multi-parametric decision model based on fuzzy logic is proposed. The model calculates course alteration in a collision avoidance situation. First, the model collects input data of the target vessel and assesses the collision risk. Using time delay, four parameters are calculated for further processing as input variables for a fuzzy inference system. Then, the fuzzy logic method is used to calculate the course alteration, which considers the vessel’s safety domain and International Regulations for Preventing Collisions at Sea (COLREGs). The special feature of the decision model is its tuning with the results of the database of correct solutions obtained with the manual radar plotting method. The validation was carried out with six selected cases simulating encounters with the target vessel in the open sea from different angles and at any visibility. The results of the case studies have shown that the decision model computes well in situations where the own vessel is in a give-way position. In addition, the model provides good results in situations when the target vessel violates COLREG rules. The collision avoidance planning tool can be automated and serve as a basis for further implementation of a model that considers the manoeuvrability of the vessels, weather conditions, and multi-vessel encounter situations.

Increasing home-grown forage consumption and profit in non-irrigated dairy systems. 1. Rationale, systems design and management

2014 ◽  
Vol 54 (3) ◽  
pp. 221 ◽  
Author(s):  
D. F. Chapman ◽  
J. Hill ◽  
J. Tharmaraj ◽  
D. Beca ◽  
S. N. Kenny ◽  
...  
Keyword(s):  
Milk Production ◽  
Perennial Ryegrass ◽  
Systems Design ◽  
Farming Systems ◽  
Early Summer ◽  
Annual Rainfall ◽  
Forage Production ◽  
Winter Cereal ◽  
Dairy Systems ◽  
Milk Solids

The profitability of dairy businesses in southern Australia is closely related to the amount of feed consumed from perennial ryegrass-dominant pasture. Historically, the dairy industry has relied on improvements in pasture productivity and utilisation to support profitable increases in stocking rate and milk production per hectare. However, doubts surround the extent to which the industry can continue to rely on perennial ryegrass technology to provide the necessary productivity improvements required into the future. This paper describes the design and management of a dairy systems experiment at Terang in south-west Victoria (780-mm average annual rainfall) conducted over four lactations (June 2005–March 2009) to compare the production and profitability of two forage base options for non-irrigated dairy farms. These options were represented by two self-contained farmlets each milking 36 mixed-age, autumn-calving Holstein-Friesian cows at peak: (1) well managed perennial ryegrass pasture (‘Ryegrass Max’, or ‘RM’); and (2) perennial ryegrass plus complementary forages (‘CF’) including 15% of farmlet area under double cropping with annual species (winter cereal grown for silage followed by summer brassica for grazing on the same land) and an average of 25% of farmlet area in perennial pasture based on tall fescue for improved late spring–early summer feed supply. The design of these systems was informed by farming systems models (DairyMod, UDDER and Redsky), which were used to estimate the effects of introducing different forage options on farm profitability. The design of the CF system was selected based on modelled profitability increases assuming that all forage components could be managed to optimise forage production and be effectively integrated to optimise milk production per cow. Using the historical ‘average’ pasture growth curve for the Terang district and a mean milk price of $3.71 per kg milk solids, the models estimated that the return on assets of the RM and CF systems would be 9.4 and 15.0%, respectively. The objectives of the experiment described here were to test whether or not such differences in profitability could be achieved in practice, and to determine the risks associated with including complementary forages on a substantial proportion of the effective farm area. Key results of the experiment are presented in subsequent papers.

scholarly journals Eighty years of food-web response to interannual variation in discharge recorded in river diatom frustules from an ocean sediment core

2017 ◽  
Vol 114 (38) ◽  
pp. 10155-10159 ◽  
Author(s):  
John B. Sculley ◽  
Rex L. Lowe ◽  
Charles A. Nittrouer ◽  
Tina M. Drexler ◽  
Mary E. Power
Keyword(s):  
Food Web ◽  
Sediment Core ◽  
Nutrient Loading ◽  
Field Research ◽  
Growth Conditions ◽  
Early Summer ◽  
Depositional Environments ◽  
Annual Rainfall ◽  
Algal Production ◽  
Positive Effects

Little is known about the importance of food-web processes as controls of river primary production due to the paucity of both long-term studies and of depositional environments which would allow retrospective fossil analysis. To investigate how freshwater algal production in the Eel River, northern California, varied over eight decades, we quantified siliceous shells (frustules) of freshwater diatoms from a well-dated undisturbed sediment core in a nearshore marine environment. Abundances of freshwater diatom frustules exported to Eel Canyon sediment from 1988 to 2001 were positively correlated with annual biomass ofCladophorasurveyed over these years in upper portions of the Eel basin. Over 28 years of contemporary field research, peak algal biomass was generally higher in summers following bankfull, bed-scouring winter floods. Field surveys and experiments suggested that bed-mobilizing floods scour away overwintering grazers, releasing algae from spring and early summer grazing. During wet years, growth conditions for algae could also be enhanced by increased nutrient loading from the watershed, or by sustained summer base flows. Total annual rainfall and frustule densities in laminae over a longer 83-year record were weakly and negatively correlated, however, suggesting that positive effects of floods on annual algal production were primarily mediated by “top-down” (consumer release) rather than “bottom-up” (growth promoting) controls.

scholarly journals Climate change and economic efficiency of agricultural production in the Steppe zone

2020 ◽  
pp. 56-69
Author(s):  
Yu. O. Tararico ◽  
Yu. V. Soroka ◽  
R. V. Saidak
Keyword(s):  
Climate Change ◽  
Water Supply ◽  
Agricultural Production ◽  
Cropping System ◽  
Weather Conditions ◽  
Steppe Zone ◽  
Annual Rainfall ◽  
Winter Rape ◽  
Average Value ◽  
Dry Steppe

Relevance of research. Due to ongoing climate change, almost the entire territory of the Steppe of Ukraine by annual humidity factor belongs to the dry and very dry zones, the relative area of ​​which has increased by 13.2% of the total area of ​​the country compared to the 1960-1990s. At the same time, for today in Ukraine only about 500 thousand hectares are actually irrigated, that is 19% of the potential area. Purpose of research. To determine the patterns and trends of climate change in the western part of the dry Steppe of Ukraine and analyze the economic indicators of production activity in the region as to the variable weather conditions. Research methodology. Climate change was estimated on the basis of Climate Water Balance (CWB) and Hydrothermal Coefficient (HTC) values. The analysis of the economic efficiency of agricultural production was carried out by analyzing the statistical data for Odessa region and for the chosen agricultural enterprise. Research results and conclusions. The use of significant heat supply in the dry Steppe zone is limited by insufficient water supply conditions. In the years of 1991-2016  the average annual rainfall was 480 mm and since the early 2000s there has been a slight increase in that. However, even having 500-550 mm of average annual rainfall that has been observed over the past five years, it is not enough for providing high-yield agricultural production. High thermal regime couses high evaporation that in turn, leads to water supply deficit, which at the end of the growing season amounts to 336-436 mm. According to the HTC index in the region 80% of cases show severe and moderately arid vegetation conditions. At the same time, irrigation area in the region has decreased to a minimum, which has led to the domination of winter cereals and sunflower in the cropping system. Under variable weather conditions, winter wheat yields ranged from 19.4 to 38.5 c/ ha (31.4 c/ha on average) and sunflower - from 12.2 to 21.4 c/ha (17.4 c/ha on average), winter rape - from 13.1 to 20.9 c/ha (18.2 c/ha). It was proved a close direct relationship between the sale price of products of all studied crops and their cost price, as well as the inverse relationship of these indicators with the crop yield. The profitability of winter wheat from 2011 till 2016 ranged from 17 to 153 USD/ha with an average value of 86 USD/ha, winter rape - from 39 to 273 USD/ha with an average value of 166 USD  ha and sunflower - from 116 to 315 USD/ha with an average value of 192 USD/ha. Corn and soybeans have proven to be unprofitable in some years, which obviously explains rather small areas under these crops in the region. Above mentioned demonstrates the high economic instability of agricultural production in changing weather conditions, which is accompanied by significant risks for producers, especially when attracting credits. This situation, in turn, leads to a limited use of intensification means, in particular mineral fertilizers, which promotes agrochemical soil degradation. Under unstable water supply, the magnitude of net profit variation per hectare of arable land in Odessa region is 33-188 USD/ha (111 USD/ha on average). It is possible to increase these indicators by increasing the share of winter rape in the cropping system. With the optimization of the water and air soil regimes as well as crop rotation factor, the profitability of agricultural production in the region can be increased up to 580-600 USD/ha. Similar results were obtained after analyzing the statistical data from the southern regions within the dry steppe zone.

Hönnun og virkni léttra gróðurþaka við íslenskar aðstæður

2018 ◽  
Vol 24 ◽  
pp. 31-41
Author(s):  
Halla Einarsdóttir ◽  
Ágúst Elí Ágústsson ◽  
Hrund Ólöf Andradóttir ◽  
Magnús Bjarklind ◽  
Reynir Sævarsson
Keyword(s):  
Air Temperature ◽  
Water Retention ◽  
Center Of Mass ◽  
Weather Conditions ◽  
Green Roofs ◽  
Early Summer ◽  
Successful Design ◽  
Peak Runoff ◽  
Local Materials ◽  
Grass Turf

Green roofs are increasingly being installed cities in Europe as a part of sustainable stormwater systems. The goal of this research was to assess the hydrological efficiency of different configurations of extensive green roofs in Iceland and present suggestions for successful design of such roofs based on local materials and weather conditions. International literature and best design practices were reviewed. Runoff from five test roofs was monitored for 11 months, in conjunction with snowdepth, rainfall, wind and air temperature. Green roof water retention measured highest 85% in June and July in accordance with other studies in cold climates. Water retention measured, however, somewhat lower during the winter (<20%). Significant delay of runoff's center of mass and lowering of peak runoff was measured in all green roofs except during the largest runoff events. Average event water retention was correlated to air temperature, cumulative rain, rain 14 days before event and wind speed 7 days before event. Roofs with moss and sedum turf demonstrated good hydrological efficiency, good appearance and needed little maintenance. Grass turf roofs retained slighlty more water, but were less drought resistant and looked poorly during early summer. Wild, water resistent plants like moss and sedum performed better overall.

Effects of geographical and climatic factors on cystic echinococcosis in south-western Iran

2020 ◽  
Vol 94 ◽  
Author(s):  
A. Jamshidi ◽  
A. Haniloo ◽  
A. Fazaeli ◽  
M.A. Ghatee
Keyword(s):  
Land Cover ◽  
Cystic Echinococcosis ◽  
Geographical Information Systems ◽  
Climatic Factors ◽  
Weather Conditions ◽  
Climatic Conditions ◽  
Geographical Information ◽  
Annual Rainfall ◽  
Mean Annual Temperature ◽  
Western Iran

Abstract Cystic echinococcosis (CE) is caused by the larval form of Echinococcus granulosus that can cause serious health and economic problems in the endemic foci. CE is globally distributed in various climatic conditions from circumpolar to tropical latitudes. Iran is an important endemic area with a spectrum of weather conditions. The aim of this study was to determine the effects of geo-climatic factors on the distribution of livestock CE in south-western Iran (SWI) in 2016 to 2018. Data of livestock CE were retrieved from veterinary organizations of four provinces of SWI. The geo-climatic factors, including mean annual temperature (MAT), minimum MAT (MinMAT), maximum MAT (MaxMAT), mean annual rainfall (MAR), elevation, mean annual evaporation (MAE), sunny hours, wind speed, mean annual humidity (MAH), slope, frost days and land cover, were analysed using geographical information systems (GIS) approaches. The statistical analysis showed that MAR, frost days, elevation, slope and semi-condensed forest land cover were positively and MAE, MAT, MaxMAT, MinMAT and salt and salinity land cover were negatively correlated with CE occurrence. MAE was shown to be a predictive factor in the stepwise linear logistic regression model. In short, the current GIS-based study found that areas with lower evaporation were the main CE risk zones, though those with lower temperature and higher rainfall, altitude and slope, especially where covered with or in close proximity of semi-condensed forest, should be prioritized for consideration by health professionals and veterinarians for conducting control programmes in SWI.

Factors affecting the response ofLongitarsus jacobaeae(Coleoptera: Chrysomelidae) to upwind plant odours

1996 ◽  
Vol 86 (3) ◽  
pp. 307-313
Author(s):  
Zhi-Qiang Zhang ◽  
Peter B. McEvoy
Keyword(s):  
Wind Tunnel ◽  
Host Plants ◽  
Local Density ◽  
Flea Beetle ◽  
Late Summer ◽  
Developmental State ◽  
Early Summer ◽  
Directed Movement ◽  
Factors Affecting ◽  
Plant Odours

AbstractFactors (developmental state, starvation time, host local density and host distance from insects) affecting the response of the ragwort flea beetle,Longitarsus jacobaeae(Waterhouse), to upwind plants of tansy ragwort,Senecio jacobaeae(Compositae), were examined in a wind tunnel. There was seasonal variation in beetle response to host odours. Individuals collected during spring and early summer (6 May to 14 July 1993) showed directed movement toward the upwind plants. However, individuals collected in mid-summer (23 July 1993) showed no significant response to upwind host plants and walked randomly in the wind tunnel. Individuals collected during late summer to autumn (4 August to 23 October 1994) once again showed response to upwind plants, whereas those collected in winter (January 1994) walked randomly in the wind tunnel. The absence of beetle response to plant odours coincided with potential summer aestivation and winter ‘hibernation’. For spring and early summer beetles that responded to plant odours, the strength of the response did not change significantly with the number of plants (1, 2, 4 or 6) presented upwind in the tunnel nor with the starvation time (2, 6, 10, 12, 24 or 36 h) of the tested beetles, and these patterns were consistent for male and female beetles. Individuals responded to plants from a distance of 60 and 300 cm. The speed of movement, similar for males and females, increased slightly asL. jacobaeaeoriented more directly toward host plants.

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