Ten Principles for Bird-Friendly Forestry: Conservation Approaches in Natural Forests Used for Timber Production

Bird–forestry relationships have been the subject of research and conservation initiatives for decades, but there are few reviews of resulting recommendations for use by forest managers. We define “bird-friendly forestry” as forest management that applies recommendations from research seeking to reconcile logging with bird conservation in natural forests used for timber production. We reviewed relevant studies to synthesize 10 principles of bird-friendly forestry: (1) protect and enhance vertical structure through uneven-aged silviculture; (2) leave abundant dead wood in different decay stages; (3) maintain residual large green trees; (4) create and maintain sufficient amounts of uncut reserves and corridors; (5) maximize forest interior by retaining large contiguous forest tracts in landscapes with sufficient functional connectivity; (6) maintain buffers along streams, rivers, and wetlands cultural and urban landscapes; (7) maintain horizontal stand structure and enhance vegetation diversity by creating canopy gaps; (8) extend the temporal scale of logging cycles; (9) minimize post-logging disturbance to forests, particularly during the bird breeding season; and (10) manage for focal species and guilds. These principles may serve as guidelines in developing bird-friendly management plans customized for regional priority species, with a clearly articulated vision and quantitative objectives through which success can be measured

Conversation Ecology of the Black Stork in Latvia

Autors pētīja melnā stārķa ligzdošanas ekoloģiju un ligzdošanas sekmes ietekmējošus faktorus Latvijā 1979.–2010. g. Analīzei izmantotas 1634 ligzdu kontroles, ligzdu pamešanas iemesli analizēti, izmantojot datus par 301 ligzdu 257 teritorijās. DDT ietekmes noskaidrošanai materiāls ievākts arī Igaunijā, Polijā, Vācijā, Čehijā un Beļģijā. Darbā ir 35 tabulas un 30 attēli. Melnā stārķa ligzdošanas sekmes ir būtiski pasliktinājušās. Svarīgākais ligzdošanas dzīvotnes nosacījums ir iepriekšējās paaudzes priežu un ozolu, bet mežos, kur ozolu nav, lielu apšu klātbūtne. Ligzdas vietas izvēle ir kompromiss starp ligzdas drošību pret postījumiem, iespēju tai piekļūt un stabilitāti. Lai gan postījumu skaits ir būtiski pieaudzis, tas nepārsniedz dabisku plēsēju ietekmes līmeni netraucētos mežos. Būtiska negatīva loma ir mežsaimnieciskās darbības traucējumiem, it īpaši pavasarī. Tādēļ ap 70% traucēto pāru ir neproduktīvi, kas ir galvenais kopējo ligzdošanas sekmju pazemināšanās iemesls. Pēdējos gados palielinās DDT un tā izomēru negatīvā loma. Šis piesārņojums izraisa ligzdošanas sezonas aizkavēšanos, pasliktina ligzdošanas sekmes un jauno putnu izdzīvotību. Darbā izstrādātas rekomendācijas saimnieciskās darbības izmaiņām un priekšlikumi izmaiņām dabas aizsardzības likumdošanā. Pētījumi laika gaitā finansēti no dažādiem avotiem, atsevišķas nozīmīgākās pētījuma daļas finansējuši Latvijas Dabas fonds (1990.–1996.), AS "Latvijas valsts meži" (2004.– 2008.), Fonds „Stork Foundation” (2008.–2010., Vācija) un Eiropas Sociālais Fonds (projekts ”Atbalsts doktora studijām Latvijas Universitātē”, 2010). Atslēgvārdi: melnais stārķis, mežsaimniecības ietekme, traucējumi, dzīvotnes kvalitāte, DDT, plēsēju ietekmeThe author studied the breeding ecology of Black Stork and factors affecting breeding performance in Latvia from 1979–2010. Analysed data are based on 1634 controlled nests, the reasons for nest abandonment were studied using data from 301 nests in 257 territories. In order to study the impact of DDT on breeding success, data on egg measures and organochlorine content were also gathered in Estonia, Poland, Czech Republic, Germany and Belgium. Paper contains 35 Tables and 30 Pictures. Breeding success of Black stork has declined significantly during the study period, and the main aim of the study was to elucidate which factors could be made responsible for this decline. The most important features of the breeding habitat is the presence of large oaks, pines or aspens. Position of a nest is a trade-off between predation security, access and nest-site stability. Although predation level has increased significantly during the study, it does not exceed that in undisturbed natural forests. Forestry disturbance particularly in spring was found to be the most significant factor affecting breeding success, resulting in breeding failure of up to some 70% of affected pairs. The role of chemical contamination (DDT) has been increasing during the last years, causing an increased rate of egg loss, delay in breeding season and reduced juvenile survival. Recommendations for changes in forestry practice and legislation are suggested and discussed. Different funding sources have been used in various periods of the work. Separate important parts of this survey have been funded by the Latvian Fund for Nature (1990–1996), the Stock Company "Latvijas valsts meži" (2004–2008), „The Stork Foundation” (2008–2010, Germany) and the European Social Fund (2010). Keywords: Black Stork, forestry impact, disturbance, habitat quality, DDT, predator impac

Conversation Ecology of the Black Stork in Latvia

Autors pētīja melnā stārķa ligzdošanas ekoloģiju un ligzdošanas sekmes ietekmējošus faktorus Latvijā 1979.–2010. g. Analīzei izmantotas 1634 ligzdu kontroles, ligzdu pamešanas iemesli analizēti, izmantojot datus par 301 ligzdu 257 teritorijās. DDT ietekmes noskaidrošanai materiāls ievākts arī Igaunijā, Polijā, Vācijā, Čehijā un Beļģijā. Darbā ir 35 tabulas un 30 attēli. Melnā stārķa ligzdošanas sekmes ir būtiski pasliktinājušās. Svarīgākais ligzdošanas dzīvotnes nosacījums ir iepriekšējās paaudzes priežu un ozolu, bet mežos, kur ozolu nav, lielu apšu klātbūtne. Ligzdas vietas izvēle ir kompromiss starp ligzdas drošību pret postījumiem, iespēju tai piekļūt un stabilitāti. Lai gan postījumu skaits ir būtiski pieaudzis, tas nepārsniedz dabisku plēsēju ietekmes līmeni netraucētos mežos. Būtiska negatīva loma ir mežsaimnieciskās darbības traucējumiem, it īpaši pavasarī. Tādēļ ap 70% traucēto pāru ir neproduktīvi, kas ir galvenais kopējo ligzdošanas sekmju pazemināšanās iemesls. Pēdējos gados palielinās DDT un tā izomēru negatīvā loma. Šis piesārņojums izraisa ligzdošanas sezonas aizkavēšanos, pasliktina ligzdošanas sekmes un jauno putnu izdzīvotību. Darbā izstrādātas rekomendācijas saimnieciskās darbības izmaiņām un priekšlikumi izmaiņām dabas aizsardzības likumdošanā. Pētījumi laika gaitā finansēti no dažādiem avotiem, atsevišķas nozīmīgākās pētījuma daļas finansējuši Latvijas Dabas fonds (1990.–1996.), AS "Latvijas valsts meži" (2004.– 2008.), Fonds „Stork Foundation” (2008.–2010., Vācija) un Eiropas Sociālais Fonds (projekts ”Atbalsts doktora studijām Latvijas Universitātē”, 2010). Atslēgvārdi: melnais stārķis, mežsaimniecības ietekme, traucējumi, dzīvotnes kvalitāte, DDT, plēsēju ietekmeThe author studied the breeding ecology of Black Stork and factors affecting breeding performance in Latvia from 1979–2010. Analysed data are based on 1634 controlled nests, the reasons for nest abandonment were studied using data from 301 nests in 257 territories. In order to study the impact of DDT on breeding success, data on egg measures and organochlorine content were also gathered in Estonia, Poland, Czech Republic, Germany and Belgium. Paper contains 35 Tables and 30 Pictures. Breeding success of Black stork has declined significantly during the study period, and the main aim of the study was to elucidate which factors could be made responsible for this decline. The most important features of the breeding habitat is the presence of large oaks, pines or aspens. Position of a nest is a trade-off between predation security, access and nest-site stability. Although predation level has increased significantly during the study, it does not exceed that in undisturbed natural forests. Forestry disturbance particularly in spring was found to be the most significant factor affecting breeding success, resulting in breeding failure of up to some 70% of affected pairs. The role of chemical contamination (DDT) has been increasing during the last years, causing an increased rate of egg loss, delay in breeding season and reduced juvenile survival. Recommendations for changes in forestry practice and legislation are suggested and discussed. Different funding sources have been used in various periods of the work. Separate important parts of this survey have been funded by the Latvian Fund for Nature (1990–1996), the Stock Company "Latvijas valsts meži" (2004–2008), „The Stork Foundation” (2008–2010, Germany) and the European Social Fund (2010). Keywords: Black Stork, forestry impact, disturbance, habitat quality, DDT, predator impac

Melnā stārķa saglabāšanas ekoloģija Latvijā

Autors pētīja melnā stārķa ligzdošanas ekoloģiju un ligzdošanas sekmes ietekmējošus faktorus Latvijā 1979.–2010. g. Analīzei izmantotas 1634 ligzdu kontroles, ligzdu pamešanas iemesli analizēti, izmantojot datus par 301 ligzdu 257 teritorijās. DDT ietekmes noskaidrošanai materiāls ievākts arī Igaunijā, Polijā, Vācijā, Čehijā un Beļģijā. Darbā ir 35 tabulas un 30 attēli. Melnā stārķa ligzdošanas sekmes ir būtiski pasliktinājušās. Svarīgākais ligzdošanas dzīvotnes nosacījums ir iepriekšējās paaudzes priežu un ozolu, bet mežos, kur ozolu nav, lielu apšu klātbūtne. Ligzdas vietas izvēle ir kompromiss starp ligzdas drošību pret postījumiem, iespēju tai piekļūt un stabilitāti. Lai gan postījumu skaits ir būtiski pieaudzis, tas nepārsniedz dabisku plēsēju ietekmes līmeni netraucētos mežos. Būtiska negatīva loma ir mežsaimnieciskās darbības traucējumiem, it īpaši pavasarī. Tādēļ ap 70% traucēto pāru ir neproduktīvi, kas ir galvenais kopējo ligzdošanas sekmju pazemināšanās iemesls. Pēdējos gados palielinās DDT un tā izomēru negatīvā loma. Šis piesārņojums izraisa ligzdošanas sezonas aizkavēšanos, pasliktina ligzdošanas sekmes un jauno putnu izdzīvotību. Darbā izstrādātas rekomendācijas saimnieciskās darbības izmaiņām un priekšlikumi izmaiņām dabas aizsardzības likumdošanā. Pētījumi laika gaitā finansēti no dažādiem avotiem, atsevišķas nozīmīgākās pētījuma daļas finansējuši Latvijas Dabas fonds (1990.–1996.), AS "Latvijas valsts meži" (2004.– 2008.), Fonds „Stork Foundation” (2008.–2010., Vācija) un Eiropas Sociālais Fonds (projekts ”Atbalsts doktora studijām Latvijas Universitātē”, 2010). Atslēgvārdi: melnais stārķis, mežsaimniecības ietekme, traucējumi, dzīvotnes kvalitāte, DDT, plēsēju ietekmeThe author studied the breeding ecology of Black Stork and factors affecting breeding performance in Latvia from 1979–2010. Analysed data are based on 1634 controlled nests, the reasons for nest abandonment were studied using data from 301 nests in 257 territories. In order to study the impact of DDT on breeding success, data on egg measures and organochlorine content were also gathered in Estonia, Poland, Czech Republic, Germany and Belgium. Paper contains 35 Tables and 30 Pictures. Breeding success of Black stork has declined significantly during the study period, and the main aim of the study was to elucidate which factors could be made responsible for this decline. The most important features of the breeding habitat is the presence of large oaks, pines or aspens. Position of a nest is a trade-off between predation security, access and nest-site stability. Although predation level has increased significantly during the study, it does not exceed that in undisturbed natural forests. Forestry disturbance particularly in spring was found to be the most significant factor affecting breeding success, resulting in breeding failure of up to some 70% of affected pairs. The role of chemical contamination (DDT) has been increasing during the last years, causing an increased rate of egg loss, delay in breeding season and reduced juvenile survival. Recommendations for changes in forestry practice and legislation are suggested and discussed. Different funding sources have been used in various periods of the work. Separate important parts of this survey have been funded by the Latvian Fund for Nature (1990–1996), the Stock Company "Latvijas valsts meži" (2004–2008), „The Stork Foundation” (2008–2010, Germany) and the European Social Fund (2010). Keywords: Black Stork, forestry impact, disturbance, habitat quality, DDT, predator impac

Conservation ecology of the black stork in Latvia

The Latvian Fund for Nature (1990-1996), The Stock Company "Latvijas valsts meži" (2004-2008), "The Stork Foundation" (2008-2010, Germany), The European Social Fund (2010

Woven Structures from Natural Fibres for Reinforcing Composites

The increase of production of woven structures from natural fibres for reinforced composites can be noticed in different sectors of economy. This can be explained by limited sources of raw materials and different environmental issues, as well as European Union guidelines for car manufacture [4]. This research produced 2D textile structures of hemp yarn and polypropylene yarn and tested the impact of added glass fibre yarn on the mechanical properties of the woven structures and the composites produced from them. The woven structures were manufactured using hand looms or industrial looms (CТБ-175) using one layer technique. The mechanical testing of the reinforcements showed that the parameters of the looms had significant impact on the properties of the reinforcements. However, the desired improvement of strength by adding glass fibre to the fabric was not achieved. The one, two, three and four layer composites were produced in a hydraulic press using reinforcements woven from hemp yarn and polypropylene yarn. The mechanical testing of composites showed that the tensile strength of the composites and the tensile stress at maximum load depends on number of the reinforcement layers, but the tensile extension of the composites and the modulus of elasticity are not closely related to the number of reinforcement layers, but rather on elasticity of yarn used in weaving. Swelling of composites in water was detected

Composites with Hemp Fibers Woven Reinforcements

The research focuses on hemp yarns activity in the woven reinforcements, depending on the production method as well as production of reinforcement of natural yarns and thermoplastic yarns as matrix in one woven product for production of composites of building materials. The reinforcements of hemp yarns (100 tex), polypropylene yarns (100 tex) and polyethylene yarn (220 tex) were produced using plain weaving technique on a craftsman’s loom. The measurement of fabric thickness and physical-mechanical properties of reinforcements were carried out according to ISO 5084:1996 and LVS EN ISO 13934-1-2001 standards. Fabric thickness of hemp yarns reinforcement was 0.61-0.69 mm and density 91-100 g/m2. Tensile strength of hemp reinforcement on warp direction are 241.7N-279.8N and on weft direction 249.4N -302.9N; tensile modulus 218.48MPa-271.24MPa and 189.3 MPa-196.1MPa. Laboratory Press LP_S_50/SASTM) was used for production of composites. The mechanical properties of composite were established according to ISO 527-5:2009 standard and thickness swelling in water was conducted in accordance to EN 622-2: 2004 standard. Composite thickness depending of reinforcement layers in composites was 0.34mm to1.1mm; the density of composites varied from 311 g/m2 to 1040 g/m.2 Tensile strength of composites varied from 303.09N (one layer) to 2019.39N (five layers) and the elastic modulus of same composites are 908.24MPa and 1809.64 MPa