Search results for "Pinu"

Pacilās vai vagās stādīto priedes (Pinus sylvestris) un egles (Picea abies) stādu agrīnā attīstība āreņos un citi meža atjaunošanas sekmīgumu ietekmē…

2017

Augsnes sagatavošana ir plaši izmantota prakse parastās egles (Picea abies) un parastās priedes (Pinus sylvestris) audžu atjaunošanā. Visplašāk izmantotās augsnes sagatavošanas metodes ir vagu un pacilu izveide, šīs metodes uzlabo stādu augšanu un palielina izdzīvojušo stādu skaitu salīdzinājumā ar neapstrādātu augsni. Neskatoties uz šo augsnes sagatavošanas veidu plašo pielietojumu mežu atjaunošanā Latvijā, līdz šim nebija veikti pētījumi, kas salīdzinātu vagu un pacilu sekmību āreņu tipa mežos. Pētījums tika veikts 2016. gadā, periodā no jūlija beigām līdz augusta beigām. Apsekotās audzes bija atjaunotas pirms viena līdz trīs gadiem. Mērķis bija noskaidrot, kurš no apstrādes veidiem snieg…

Glyphosate residues alter the microbiota of a perennial weed with a minimal indirect impact on plant performance

2021

Abstract Purpose In cold climates, glyphosate residues may linger in soils, with effects on plant–microbe interactions and, consequently, plant performance. Here, we explore the influence of glyphosate residues on the endophytic microbiota (bacteria and fungi) and performance of the perennial nitrogen-fixing weed Lupinus polyphyllus. Methods In a common garden, we grew plants from six populations of L. polyphyllus in glyphosate-treated or untreated control soils, with or without additional phosphorus. We sampled plant microbiota (leaves, roots, nodules) and assessed plant performance based on six traits: height, retrogression probability (i.e. shrinkage), biomass, root:shoot ratio, nodule n…

Maintenance of genetic variation in sexual ornamentation : role of precopulatory and postcopulatory sexual selection

2010

Celmeņu Armillaria spp. dzīvotspēja un patogenitāte Latvijas izcelsmes priežu Pinus sylvestris un egļu Picea abies stādos

2017

Celmeņu Armillaria spp. ģints sēņu izraisītā sakņu trupe ir iemesls ievērojamiem mežsaimnieciskajiem zaudējumiem. Darbā analizēta Armillaria solidipes, A. cepistipes un A. borealis dzīvotspēja, izplatīšanās potenciāls un patogenitāte 5-6 gadus vecos parasto priežu (563 gab.) un parasto egļu (350 gab.) stādos. Armillaria spp. inokulātu attīstība novērota stādu audzēšanai paredzētajā kūdras substrātā. Novērojumus priežu un egļu stādiem veica pēc attiecīgi 12 un 15 mēnešiem. Patogēna dzīvotspēja bija atkarīga no tā sugas: A. cepistipes būtiski augstāka, bet A. solidipes viszemākā. Augstāko izplatīšanās potenciālu konstatēja A. cepistipes, bet viszemāko A. solidipes. Visas trīs Armillaria sugas…

Phlebiopsis gigantea attīstība maza diametra skuju koku celmos

2016

Lai novērtētu P. gigantea micēlija attīstību skuju koku celmos sastāva kopšanas cirtēs, četrās audzēs Vidusdaugavas mežsaimniecībā tika ierīkots eksperiments, kurā ar „Rotstop” un divu Latvijas P. gigantea izolātu konīdijsporu suspensijām apstrādāja maza diametra (3 – 12 cm) parasto egļu un parasto priežu celmus. Pēc gada tika ievākti koksnes paraugi un analizēta P. gigantea attīstība celmos. P. gigantea izolāti labāk attīstījās maza diametra priežu celmos nekā egļu celmos. Dabiskā P. gigantea infekcija konstatēta 20% maza diametra priežu celmu. Salīdzinot „Rotstop” ar vietējiem izolātiem, Latvijas izolāta PG137 attīstības biežums priežu celmos būtiski neatšķīrās un P. gigantea micēlijs sas…

In Search of Pathogens: Transcriptome-Based Identification of Viral Sequences from the Pine Processionary Moth (Thaumetopoea pityocampa)

2015

Thaumetopoea pityocampa (pine processionary moth) is one of the most important pine pests in the forests of Mediterranean countries, Central Europe, the Middle East and North Africa. Apart from causing significant damage to pinewoods, T. pityocampa occurrence is also an issue for public and animal health, as it is responsible for dermatological reactions in humans and animals by contact with its irritating hairs. High throughput sequencing technologies have allowed the fast and cost-effective generation of genetic information of interest to understand different biological aspects of non-model organisms as well as the identification of potential pathogens. Using these technologies, we have o…

Produzione e utilizzazione delle biomasse dei rimboschimenti in Sicilia

2007

Per recepire l’orientamento di fondo dei principi di Kyoto e le seguenti azioni, e necessario verificare le fonti energetiche alternative, e tra queste ha rilevanza la biomassa forestale. L’utilizzo di questa e legato tuttavia alla disponibilita sul territorio e alla sua dispersione. Il lavoro presentato analizza le principali fonti di biomasse presenti sull’isola, la loro dispersione e entita di prelievo sostenibile, ipotizza la possibilita di recupero a fini energetici del materiale di scarsa qualita prodotto in impianti di arboricoltura da legno. Infine viene analizzato il contributo possibile degli impianti di eucalitto diffusamente presenti su parte del territorio siciliano, anche nell…

Nemoralisation of Pinus sylvestris and Picea abies Forest Stands in the Hemi-Boreal Zone: A Case Study from Latvia

2021

Abstract At the beginning of the 21st century, in extensively managed mature and over-mature conifer stands (Pinus sylvestris and Picea abies) in Latvia, establishment of native deciduous broad-leaved (Acer platanoides, Tilia cordata, Quercus robur and Ulmus laevis), as well as alien broad-leaved species (Acer pseudoplatanus and Tilia platyphyllos) has been observed. The establishment of deciduous broad-leaved species in coniferous stands is a process known as nemoralisation of coniferous stands, which is characterised by a large number of seedlings of broad-leaved species, young trees and the formation of a subcanopy layer in stands. Based on the age measurements of individuals of broad-le…

Environmental impact of magmatic fluorine emission in the Mt. Etna area

2007

-UniversitA degli Studi di Palermo, Italy -Istituto Nazionale di Geofisica e Vulcanologia, Sezione di Palermo - Unione Europea, Fondo Sociale Europeo

Volatile Oil Content of Scots Pine Needles (Pinus sylvestris L.)

2016

Abstract This study focused on how the concentration of volatile oils in Scots Pine needles varied in relation to the age of the trees, the age of the needles and their location within the canopy. Study material were pine needles from 15-, 44- and 89-year-old pine stands. The mean content of oils increased with the age of trees. The averaged oil content in needles was: 0.46% in the 15-year-old stand, 0.55% in the 44-year-old and 0.61% in the 89-year-old stands. The mean content of volatile oils decreased with the age of the needles. 1-year-old needles contained the highest concentration of volatile oils (0.56%), and the 3-year-old needles contained the least (0.48%). In 15-year-old stands t…