Search results for ":FORESTRY"
showing 10 items of 65 documents
Latvijas mežu vēsture (līdz 1940. gadam): mežu vēstures bibliogrāfija
1996
Saturs: Ievadam 3 Rādītājā lietotie saīsinājumi 4 Vispārējie materiāli 6 Mežu politika un likumdošana 24 Mežainība. Koku sugas 37 Meža dzīvnieki un medniecība 49 Meža izmantošana 56 Meža blakus izmantošana 62 Meža materiālu eksports un imports 64 Meža muzeji 68 Personālijas 69
Leaf life span and the mobility of "non-mobile" mineral nutrients - The case of boron in conifers
2002
Nutrient conservation is considered important for the adaptation of plants to infertile environments. The importance of leaf life spans in controlling mean residence time of nutrients in plants has usually been analyzed in relation to nutrients that can be retranslocated within the plant. Longer leaf life spans increase the mean residence time of all mineral nutrients, but for non-mobile nutrients long leaf life spans concurrently cause concentrations in tissues to increase with leaf age, and consequently may reduce non-mobile nutrient use efficiency. Here we analyze how the role of leaf life span is related to the mobility of nutrients within the plant. We use optimality concepts to derive…
Ģeogrāfija. Ģeoloģija. Vides zinātne: referātu tēzes
2008
The cork oak in the Mountains of Palermo (Italy): ecological insights from the south-eastern edge of its distribution range
2020
Abstract: The uneven presence of the cork oak (Quercus suber L.) within its distribution range is not only determined by its climatic requirements but also by specific edaphic needs. Although most of the natural populations thrive in acidic soils deriving from metamorphic or volcanic rock outcrops, some cork oak populations are found growing in soils deriving from calcareous bedrock, which are considered less suitable. We carried out a multidisciplinary investigation at the south eastern edge of the Q. suber distribution range (Mountains of Palermo, NW Sicily), including soil, floristic, and vegetation surveys, aimed at: (i) assessing the native or introduced origin of some peculiar cork oa…
On the hidden significance of differing micro-sites on tree-ring based climate reconstructions
2015
Tree-ring chronologies are commonly extended back in time by combining samples from living trees with relict material preserved in man-made structures or natural archives (e.g. lakes). Although spatially close, these natural archives and living-tree-sites often comprise different micro-climates. Inhomogeneous growth conditions among these habitats, which may yield offsets in growth-rates, require caution in data processing. Here we assess species-specific growth dynamics in two micro-habitats and their potential effects on long chronologies by combining tree-ring data from different living-tree-sites with an âartificialâ subfossil dataset. Well replicated (nâ>â80) Norway spruce (…
Impact of wheeled and tracked tractors on soil physical properties in a mixed conifer stand
2016
Abstract: Damage to forest soil caused by vehicle traffic mainly consists of soil compaction, displacement, and rut formation. Severity of the damage depends on vehicle mass, weight of the carried loads, ground morphology, and soil properties, such as moisture. This paper investigates the impacts of two types of vehicles (tracked or wheeled tractor), traffic intensities (one or five skidding cycles) and soil moisture (24% or 13% by weight) on compaction of a loam textured soil in a mixed conifer stand of central Italy. Changes in porosity, bulk density, shear and penetration resistances were analyzed. The latter three parameters were significantly higher in the trafficked soil portions than…
Kā Paleijas Jahnis sawu buhschanu kohpis [Kā Paleijas Jānis savu būšanu kopis]
1844
Pilnasiņu zirgi sacīkstēs un vaislā
1932
Tekstu papildina 20 ilustrācijas un 71 tabula.
Innovative and Applied Research in Biology: Proceedings, Vol.1
2019
Projekti: ZD2016/AZ81 & ZD2016/AZ107
Stand structure and spatial pattern of regeneration of Pinus sylvestris in a natural treed mire in Latvia
2009
We examined the regeneration patterns of Pinus sylvestris L. in a natural treed mire in the hemiboreal zone in Latvia. Data on tree stem age and size was collected in 207 fine-scale plots (10 m) and 4 medium-scale plots (400 m). Size structure of living and dead trees was also estimated on transects 180-m and 250-m length and 10-m width. In addition, the vegetation was described in 1-m plots to determine preferred microsites for P. sylvestris establishment. Pinus sylvestris showed continuous regeneration by an inverse J-shaped age and size structure. Pulses of mortality induced by fire were also evident. Regeneration of P. sylvestris was mostly on Sphagnum magellanicam Brid. hummocks free o…