The poplar (Populus spp.) plays an important role in worldwide forest economy, responding to the necessities of obtaining high biomass production in a short time. Short rotation forests (SRF) are developing continuously in Romania. Several studies have been undertaken to identify the clones with high productivity and suitable technologies. The aim of this study was to register the annual increments in diameter, height and volume in an experimental poplar crops with a short-term rotation of 5 years. The poplar cultures are composed from 6 types of hybrid poplar clones (AF2, AF6, Monviso, A4A, Pannonia and Max4) with a density of 2667 trees ha-1. The research results show a clear differentiation among clones’ increments. The highest increments were obtained with AF2 and AF6 clones in five years, with almost 0.038 m3 an-1. The lowest increment was observed for Max4 clone with 0.028 m3. | Plopul (Populus spp.) joacă un rol important în economia forestieră mondială, răspunzând necesităților de a obține producții ridicate de biomasă în timp scurt. Culturile cu ciclu scurt de producție au o dezvoltare continuă în România. Numeroase studii au fost dezvoltate pentru identificarea clonelor cu productivitatea cea mai ridicată în contextul unor tehnologii adegvate. Scopul acestui studiu a fost a înregistra creșterile anuale în diametru, înălțime și volum, într-o cultură experimentală de plop, cu un ciclu de producție de 5 ani. Culturile de plop analizate sunt alcătuite din 6 clone de plop hibrid (AF2, AF6, Monviso, A4A, Pannonia și Max4), plantate cu o densitate de 2667 de exemplare ha-1. Rezultatele cercetării arată o diferențiere clară între creșterile clonelor. Cele mai mari creșteri au fost obținute la clone AF2 și AF6 în cinci ani, de aproape 0,038 m3 an-1. Cea mai mică creștere a fost observată pentru clona Max4 cu 0,028 m3.

The poplar (Populus spp.) plays an important role in worldwide forest economy, responding to the necessities of obtaining high biomass production in a short time. Short rotation forests (SRF) are developing continuously in Romania. Several studies have been undertaken to identify the clones with high productivity and suitable technologies. The aim of this study was to register the annual increments in diameter, height and volume in an experimental poplar crops with a short-term rotation of 5 years. The poplar cultures are composed from 6 types of hybrid poplar clones (AF2, AF6, Monviso, A4A, Pannonia and Max4) with a density of 2667 trees ha-1. The research results show a clear differentiation among clones’ increments. The highest increments were obtained with AF2 and AF6 clones in five years, with almost 0.038 m3 an-1. The lowest increment was observed for Max4 clone with 0.028 m3.

The knowledge of the particularities of seeds germination on different substrat types is important, especially from the point of vue of ecological restoration, e.g. of the dumps. The paper presents the results of the Norway spruce seeds germination on different substrates (10 variants: 9 + Control) from an area of a surface mining sulfur (Călimani) from the North of Eastern Carpathians. The germination tests indicated, in an expected way, that the only substrate which significantly influence the germination (at 7, 10 and 15 days, respectively) was the sulphur, in case of the other the differences being non-significant. The minimum beard length values were recorded on sulphur substrate, while the best on the ‘forest soil’ variant. The germination threshold (2 mm) was reached after 3-5 days, and the phytotoxicity effect was observed after 10 days. Regarding the time length of the germination phase, the most favourable (shortest) was the ‘Hummus’ variant. The correlation analysis indicated that if the germination period is short, then the other phases will be prolonged, with larger percent of germination and relative beard length. In an expected way, the fatal effect of the ‘Sulphur’ substrate is different than all the others, starting with the 11th day of germination. Based on the obtained results, for the area were delineated three domains of relative toxicity: A - toxic (without life conditions), B - neutral (inhibition of the physiological processes) and C - favourable (proper for a plant development), which were mapped for further practical use.

Drought is main climatic risk factor in Republic of Moldova with major effects on economic and ecologic level. Regional climatic models indicate for Moldova an increase of temperature and decrease of precipitation during the summer in the future decades. We evaluated the response of beech and oak to cumulative water deficit using SPEI index at different time scales. Results of climate-growth correlations indicate a higher sensitivity of beech to drought comparing with oak. Maximum correlation for beech is observed at 18-20 month SPEI scale (0.60) and for oak at time scale of 12-18 month, but lower (0.45). Earlywood growth index of oak are low correlated with SPEI. Oak, a more tolerant drought species, is more adapted compared with beech under the forescasted climatic changes in this region.