scholarly journals Increasing numbers of wintering forest birds in Swedish Lapland 1986–2017 show stronger correlations with forest development than with local weather

Ornis Svecica ◽  
2020 ◽  
Vol 30 ◽  
pp. 13-30
Author(s):  
Björn Ferry ◽  
Håkan Rune ◽  
Ulf Andersson ◽  
Martin Green

After a long period of decline, the number of forest birds has increased in Sweden in recent decades. Whether this trend is due to an increase in forested area, forest quality, climate change, or a combination of these factors, remains unclear. Here, we compared forest bird data from a local winter point count route around Storuman in Swedish Lapland between 1986 and 2017, with the development of regional forest composition and local weather conditions. We suggest that rather than changes in average annual, winter, or summer local temperatures or precipitation, the main drivers behind increasing numbers of wintering forest birds in this part of Sweden are an increase in the area of denser forest and dead wood volume, and a decrease in open ground area without forest vegetation. While there may be supplementary explanations behind the increasing numbers of forest birds, such as reduced agriculture, decreasing local human population, or stronger photosynthesis, our results indicate that local land use has been favourable for forest birds in recent decades in this area.

1966 ◽  
Vol 98 (8) ◽  
pp. 871-875 ◽  
Author(s):  
J. B. Thomas

AbstractA survey of the insect fauna in a part of the Sierra Madre Occidental in Mexico was made in 1964 by a party of nine entomologists from the Canada Departments of Agriculture and Forestry. Approximately 50 species of Scolytidae in 20 genera were collected on this expedition and are listed with host relationships and distribution where possible. A brief discussion of the known biology of one of the major economic bark beetles, a species of Dendroctonus, is given. The local weather conditions and the forest composition are discussed generally for the benefit of future collectors in this area.


Author(s):  
María Laura Bettolli

Global climate models (GCM) are fundamental tools for weather forecasting and climate predictions at different time scales, from intraseasonal prediction to climate change projections. Their design allows GCMs to simulate the global climate adequately, but they are not able to skillfully simulate local/regional climates. Consequently, downscaling and bias correction methods are increasingly needed and applied for generating useful local and regional climate information from the coarse GCM resolution. Empirical-statistical downscaling (ESD) methods generate climate information at the local scale or with a greater resolution than that achieved by GCM by means of empirical or statistical relationships between large-scale atmospheric variables and the local observed climate. As a counterpart approach, dynamical downscaling is based on regional climate models that simulate regional climate processes with a greater spatial resolution, using GCM fields as initial or boundary conditions. Various ESD methods can be classified according to different criteria, depending on their approach, implementation, and application. In general terms, ESD methods can be categorized into subgroups that include transfer functions or regression models (either linear or nonlinear), weather generators, and weather typing methods and analogs. Although these methods can be grouped into different categories, they can also be combined to generate more sophisticated downscaling methods. In the last group, weather typing and analogs, the methods relate the occurrence of particular weather classes to local and regional weather conditions. In particular, the analog method is based on finding atmospheric states in the historical record that are similar to the atmospheric state on a given target day. Then, the corresponding historical local weather conditions are used to estimate local weather conditions on the target day. The analog method is a relatively simple technique that has been extensively used as a benchmark method in statistical downscaling applications. Of easy construction and applicability to any predictand variable, it has shown to perform as well as other more sophisticated methods. These attributes have inspired its application in diverse studies around the world that explore its ability to simulate different characteristics of regional climates.


Author(s):  
А.V. Polykov ◽  
T.V. Alekseeva

Цель исследования усовершенствование способа обогащения растений чеснока селеном до уровня суточной нормы потребления путем обработки вегетирующих растений растворами селенитов натрия и калия в сочетании с поверхностно-активными веществами и диметилсульфоксидом. Исследования проведены во ВНИИО филиале ФГБНУ ФНЦО, в условиях открытого грунта в 20162018 годах, на супесчаной почве, содержание гумуса в которой составляло 3,413,44, рНKCl 6,7, степень обеспеченности питательными веществами: фосфором высокая (содержание P2O5 в слое 020 см составляло 22,7824,62 мг (по Чирикову) калием низкая, содержание К2О в слое 20 см 10,3817,88 мг (по Масловой). Для улучшения минерального питания растений осенью под основную обработку в почву вносили калий хлористый в дозе 50 г/м2, в период вегетации проводили подкормки растений: первую, в фазе начала интенсивного роста листьев аммиачной селитрой 30 г/м2, вторую, через две недели после первой сульфатом калия 50 г/м2. Погодные условия в течение периода исследований были благоприятны для выращивания чеснока. Поливы проводили по мере подсыхания верхнего слоя почвы. Исследования проведены на чесноке озимом сорта Гладиатор. Схема опытов предполагала предпосадочное замачивание зубков в течение 30 мин. и последующую двукратную обработку вегетирующих растений 0,1-ным раствором селенита натрия и калия в сочетании с поверхностно активными веществами (1) и диметилсульфоксидом (1): первый раз в фазе начала интенсивного роста листьев и второй через три недели. Установлено, что некорневая обработка растений селенитом натрия была в 2,3 раза, а селенитом калия в 5,8 раза эффективнее, чем корневая. Сделан вывод о том, что луковицы чеснока, полученные, в результате некорневой обработки растений 0,1-ным раствором селенита натрия и калия в сочетании с поверхностно активными веществами и диметилсульфоксидом содержат в 145,3169,8 раза больше селена, чем контроль, что позволяет получить зубки, содержащие селен в концентрации 6,837,98 мг/кг. Суточная норма потребления чеснока составляет примерно 10 г, средняя потребность в селене составляет от 30 до 70 мкг. Учитывая, что содержание селена в обогащенной продукции составит 68,3 79,8 мкг/10 г чеснока предложенный способ обогащения позволяет в полной мере удовлетворить суточную потребность организма человека в этом микроэлементе.The aim of investigation was to improve the method of enrichment of garlic plants with selenium to the level of daily consumption rate by treatment of vegetative plants with solutions of sodium and potassium selenites in combination with surfactants. The investigations were carried out at ARRIVG branch of FSCVG, in open ground in 20162018, on sandy loam soil with humus content of 3.413.44, pHKCl 6.7, content of phosphorus (P2O5) in the layer 020 cm was 22.7824.62 mg (Chirikov) content of potassium (K2O) 10.3817.88 mg (Maslova). To improve mineral nutrition of plants fall under the basic treatment in the soil was added potassium chloride at a dose of 50 g/m2 during the growing season were plant nutrition: first, in the early phase of intensive growth of leaves ammonium nitrate 30 g/m2, the second, two weeks after the first potassium sulphate and 50 g/m2. Weather conditions during the period of growth were favorable for growing garlic. Watering was carried out at the periods where the top layer of soil was dried. Studies were carried out on variety Gladiator of winter garlic. The experimental design included soaking the cloves for 30 minutes before planting, and subsequent double treatment of vegetating plants with 0.1 solution of sodium and potassium selenite in combination with surfactants (1) and dimethyl sulfoxide (1): the first time in the phase of the beginning of intense leaf growth and the second time after 3 weeks. As a result of the investigations it was found that non-root treatment of plants with solutions containing selenium was more effective than root treatment. Non-root top dressing with sodium selenite was in 2.3 times, and potassium selenite in 5.8 times more effective than root. It is concluded that garlic bulbs obtained as a result of non-root treatment of plants with 0.1 solution of sodium and potassium Selenite in combination with surfactants and dimethylsulfoxide contain 145.3169.8 times more selenium than control, which allows to obtain teeth containing selenium in a concentration of 6.837.98 mg/kg. The daily consumption rate of garlic is approximately 10 g, the average need for selenium element is from 30 to 70 micrograms. Because of content of selenium in enriched products consisted of 68.3-79.8 mcg/10 g of garlic, the proposed method of enrichment allows to fully satisfy the daily need of the human body at this microelement.


2019 ◽  
Vol 29 ◽  
pp. 1-16 ◽  
Author(s):  
Jorge Flores-Velazquez ◽  
Federico Villarreal-Guerrero ◽  
Abraham Rojano-Aguilar ◽  
Uwe Schdmith

In some locations with harsh winters, the heat stored in the soil may not be enough to heating a greenhouse, and so artificial heat must be supplied. The objective of this study was to evaluate a numerical model under local weather conditions, in Humboldt University of Berlin, Germany, during winter 2011 to analyze the air dynamics generated through a tube pipe heating system convection in a closed greenhouse, for it to be applicable in producing cold regions in Mexico. Results showed that 100 W m-2 of heat released from the soil kept the environment within acceptable ranges for plant growth from noon to evening. However, the energy lost by long-wave radiation during the night lowered the air temperature to minimal basal temperature. Heat from the pipes placed underneath the crop promoted air movement by convection, producing a uniform distribution of temperature and humidity within the plant canopy.


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