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1.
Plant growth, morphology and nutritive value under shade can differ between temperate grasses. Therefore, the aim of this study was to quantify the dry matter (DM) production, sward morphology, crude protein (CP%), organic matter digestibility (OMD) and macro-nutrient concentrations (P, K, Mg, Ca and S) in a grazed cocksfoot (Dactylis glomerata L.) pasture under 10-year-old Pinus radiata D. Don forest. Four levels of light intensity were compared: full sunlight (100% photosynthetic photon flux density-PPFD), open + wooden slats (∼43% PPFD), trees (∼58% PPFD) and tree + slats (∼24% PPFD). The mean total DM production was 8.2 t DM ha−1 yr−1 in the open and 3.8 t DM ha−1 yr−1 in the trees + slats treatment. The changes in cocksfoot leaf area index (LAI) were related to variations in morphological aspects of the sward such as canopy height and tiller population. CP% increased as PPFD declined with mean values of 18.6% in open and 22.5% in the trees + slats treatment. In contrast, the intensity of fluctuating shade had little effect on OMD with a mean value of 79 ± 3.2%. The mean annual macro-nutrient concentrations in leaves increased as the PPFD level declined mainly between the open and the trees + slats treatments. It therefore appears that heavily shaded dominant temperate pastures in silvopastoral systems limit animal production per hectare through lower DM production rates and per animal through reduced pre-grazing pasture mass of lower bulk density from the etiolated pasture.  相似文献   

2.
Grasses and legumes of high productivity and nutritional quality are a good alternative as pasture supplements in rangelands of low quality forage. Orchardgrass (Dactylis glomerata L. cv. `Artabro') and white clover (Trifolium repens L. cv. `Huia') are known as shade tolerant and low flammability species that have been successfully used in agroforestry systems in Galicia, both diminishing fire hazard compared with natural shrublands. In this study, annual and seasonal production of a grass mixture of both species was quantified during 3 years in a pinewood under different tree canopy covers. Regardless of cover, pasture production increased in summer, and decreased from fall to spring. We obtained a significant correlation between annual pasture production and light transmission through the tree canopy (R2 = 0.96, P<0.05). Light transmittance through a maritime pine canopy (Pinus pinaster Ait.) was higher than through a Scots pine canopy (P. sylvestris L.), corresponding to 36–57% and 16–21% of full sunlight respectively. The highest herbage production was obtained in no tree stands and the lowest under a P. sylvestris canopy. Fluctuations inlight transmission, temperature and PAR (Photosynthetically Active Radiation) under tree canopy were less apparent compared with no tree stands. Variation in seasonal production was more pronounced in stands without trees, and appeared more uniform when percentage of light intercepted by tree canopy increased.This revised version was published online in November 2005 with corrections to the Cover Date.  相似文献   

3.
Heterobasidion species are the most important pathogens causing root and stem rot on conifers in northern hemisphere forests. The host list of this complex is very wide and includes over 200 species of trees and shrubs. Among the members of this complex, Heterobasidion annosum s. s. has the largest host range. In this study, young plants of Pinus sylvestris, Picea orientalis, Abies nordmanniana, Cedrus libani and Pinus brutia (three different origins) were inoculated on the lower stem with known genets of Heterobasidion annosum s.s. collected from Pinus brutia stands in south-western Türkiye. Infection frequency, assessed as presence of the conidial stage in stem discs following incubation, in the inoculated seedlings was 100%. The Heterobasidion annosum s. s. isolates were re-isolated from all inoculated host species. Control seedlings showed no symptoms of disease. Mortality in inoculated plants was 11.5% of the 735 inoculated plants, which died over an 8-weeks incubation period. The isolates showed greater growth on Cedrus libani, Pinus sylvestris and Picea orientalis seedlings compared to other species tested. On the other hand, it was found that the least affected seedlings were Pinus brutia TB12 and Abies nordmanniana. This study proved that differences occur in aggressiveness of Heterobasidion annosum s. s. to host species. A striking point in the results is that, despite being the host species from which the isolates were obtained, Pinus brutia seedlings showed lower sensitivity to Heterobasidion annosum s. s. than the other conifer species tested. Inoculations of three different Pinus brutia provenances suggested there was no significant difference in mean lesion lengths and fungal growth values in Pinus brutia plants, except in Pinus brutia TB14, which was more susceptible to extension growth of the pathogen.  相似文献   

4.
The success of various grass-legume mixtures in controlling competing vegetation, and their effect on subsequent survival and growth of Sitka spruce seedlings was studied on a coastal alluvial site in northwestern British Columbia. Mechanically scarified (bladed) strips were hand seeded to pure and combined mixtures of legumes, bunchgrasses, and sodforming grasses. An unseeded control (bladed but not seeded) was also established.Alsike clover (Trifolium hybridum L.) was the most successful legume species. Orchardgrass (Dactylis glomerata L.), big bluegrass (Poa ampla Merr.), and creeping red fescue (Festuca rubra L.) were the most successful grass species. Red alder (Alnus rubra Bong.) density and height were lower in legume-seeded treatments. Red elderberry (Sambucus racemosa L.) and salmonberry (Rubus spectabilis Pursh.) were effectively reduced by blading and have reestablished slowly. A combination of blading and early establishment of either sodforming grasses or bunchgrasses effectively decreased reinvasion by thimbleberry (Rubus parviflorus Nutt.).Growth of Sitka spruce was best in the unseeded control treatment or in the treatments with legumes but no sodforming grasses. Presence of sodforming grasses decreased both diameter and height growth. Sitka spruce diameter decreased with increasing red alder density. After 5 growing seasons, spruce has outgrown all competitors except red alder.  相似文献   

5.
Reduction in forage production (FP) under trees in the humid tropics is well known, but information on how different levels of nitrogen (N) fertilizer influence FP under trees is meager. The present study reports effects of four N fertilizer levels (0, 60, 80 and 120 kg ha−1 N) on net soil N mineralization rate (NMR) and soil moisture (SM), FP, shoot biomass/root biomass ratio (SB/RB), N concentration in SB, N uptake and nitrogen use efficiency (NUE) of three grasses [guinea (Panicum maximum Jacq.), para (Brachiaria mutica (Forssk) Stapf) and hybrid-napier (Pennisetum purpureum Schumach.)] under three canopy positions [under canopy (UC, representing high shade), between canopy (BC, representing low shade) and open] of coconut trees (Cocos nucifera L.) in a coconut based silvopastoral system in the humid tropical climate of South Andaman Island of India. The study was performed for two annual cycles (2005–2006 and 2006–2007). The hypotheses tested were: (1) FP would decline under tree shades, both in N fertilized as well as no N fertilized conditions, when SM was not growth limiting in the open. However, amount of decline in the FP would depend on grass species and intensity of shades i.e., higher was the shade greater would be the decline; (2) N fertilizer would increase FP under tree shades, but the increase depended on grass species, intensity of shades and amount of N applied. Amount of N applied, however, would not annul the shades effects when SM was not growth limiting in the open. The study revealed that the tree reduced light 59% under UC and 32% under BC positions, but the N fertilizer levels increased NMR by 11–51% under UC and 3–44% under BC positions compared to the open. SM did not differ across the canopy positions. Under all situations, FP of all grasses declined under UC (47–78%) and BC (18–32%) positions compared to the open; the decline was greater in Hybrid-napier than Guinea and Para grasses. Forage production of all grasses increased with N fertilizer increments under all canopy positions reaching 32 t ha−1 dry matters for hybrid-napier at 120 kg ha−1 N in the open. Both guinea and para grasses outyielded hybrid-napier grass under UC but not under BC or in the open. N concentration in the forage (SB) also increased as N fertilizer level increased. These observations support our hypotheses and suggest that forage production under coconut palms can be increased by the application of N fertilizer with both guinea and para grasses being more productive than hybrid-napier grass under the high shade. Where light conditions are better, hybrid-napier would produce more forage than the other species.  相似文献   

6.

Context   

Turkish red pine (Pinus brutia Ten.) is widespread in the eastern Mediterranean Basin. In the late 1970s, four common gardens were established along steep altitudinal transects extending from the coast to about 1,200 m in the Taurus Mountains (Antalya, Turkey).  相似文献   

7.
Micro-environmental factors viz., soil moisture and light intensity are important factors that affect natural regeneration in forests. These factors vary spatially depending on the overhead canopy density of the forest. The present study focused on studying the effect of variation of soil moisture and light intensity on natural regeneration of sal species (Shorea robusta) under different micro-environments due to overhead canopy of varying forest density. Experimental plots of 40m× 40m size were laid under different overhead canopy densities in a small sal forested watershed in the foot hills of Himalayas in Nainital District of Uttarakhand State, India. The plots were monitored on a long term basis for soil moisture at multi depths, light intensity and natural regeneration of sal. The results of the study revealed that the natural regeneration was highest under C1 (up to-0.30) canopy followed by C2 (0.30–0.50), and C3 (0.50–0.70) canopies. The C3 canopy showed the dying back of sal shoots over 4 years of study. The highest R2 value of linear regression between incremental score of plot regeneration and average soil moisture content was obtained as 0.156 for average soil moisture content during non-monsoon months at 100 cm depth. The R2 value between incremental score of plot regeneration and annual average light intensity was obtained as 0.688 which indicated that the regeneration is largely dependent on the light intensity conditions during the year. The multiple linear regression analysis between the incremental score of regeneration and the average light intensity and average soil moisture content revealed that that about 80% of variation in regeneration is explained by both the factors.  相似文献   

8.
Determination of quality parameters such as lignin and extractive content of wood samples by wet chemistry analyses takes a long time. Near-infrared (NIR) spectroscopy coupled with multivariate calibration offers a fast and nondestructive alternative to obtain reliable results. However, due to the complexity of the NIR spectra, some wavelength selection is generally required to improve the predictive ability of multivariate calibration methods. Pinus brutia Ten. is the most growing pine species in Turkey. Its rotation period is around 80 years; the forest products industry has widely accepted the use of Pinus brutia Ten. because of its ability to grow on a wide range of sites and its suitability to produce desirable products. Pinus brutia Ten. is widely used in construction, window door panel, floor covering, etc. Determination of lignin and extractive content of wood provides information to tree breeders on when to cut and how much chemicals are needed for the pulping and bleaching process. In this study, 58 samples of Pinus brutia Ten. trees were collected in Isparta region of Turkey, and their lignin and extractive content were determined with standard reference (TAPPI) methods. Then, the same samples were scanned with near-infrared spectrometer between 1,000 and 2,500 nm in diffuse reflectance mode, and multivariate calibration models were built with genetic inverse least squares method for both lignin and extractive content using the concentration information obtained from wet standard reference method. Overall, standard error of calibration (SEC) and standard error of prediction (SEP) ranged between 0.35% (w/w) and 2.40% (w/w).  相似文献   

9.
Two‐year‐old seedlings of Pinus brutia, P. brutia var. eldarica, Pinus pinea and 3‐year‐old seedlings of Pinus radiata, Pinus sylvestris, Pinus nigra and Cedrus libani were inoculated on the lower stem with isolates of Heterobasidion annosum s.s. collected from the Black Sea and Mediterranean regions of Turkey. In total, 315 seedlings were inoculated in April 2014 and incubated in a growth chamber for 7 weeks at 18–20°C. All isolates were pathogenic on the seven different hosts and had the ability to grow in living sapwood. The isolates had a greater growth on C. libani, P. sylvestris and P. radiata seedlings compared to plants of the other species tested. The least affected species were P. brutia and P. nigra. The isolates originating from the Black Sea region caused longer lesions on the hosts. Overall mortality during 7 weeks of incubation was 4%.  相似文献   

10.

• Introduction  

The accurate estimation of stem taper and volume are crucial for the efficient management of the forest resources. Compatible segmented polynomial taper and volume equations were developed for Brutian pine (Pinus brutia Ten.), Lebanon cedar (Cedrus libani A. Rich.), Cilicica fir (Abies cilicica Carr.), Scots pine (Pinus sylvestris L.), and Black pine (Pinus nigra Arnold.).  相似文献   

11.
Three different LED lamps with continuous spectra were compared against commonly used fluorescent lights. The lamps were characterized by light output, energy consumption and spectral quality for plant growth. The biological effects of light quality were compared by pre-cultivating seedlings of Picea abies (L.) Karst. and Pinus sylvestris L. under each spectrum for 35 days in a growth chamber with controlled temperature, humidity and photoperiod. The seedlings were then transplanted and cultivated for one vegetation period at the nursery, then planted outdoors on a forest field trial and followed for three years. The seedlings showed similar growth performance for all spectra tested. LED lamps have several advantages to fluorescent light such as energy consumption, longer life span and adjustable light intensity. Regarding light intensity the effects on growth performance were studied for both species using the most promising LED spectra. The photosynthetically active radiation (PAR) was maintained at 50, 100, 200 and 400 μmol?m?2?s?1. Unlike energy consumption, seedling development did not display a linear relationship to light intensity. Instead, the results show an optimum light level between 100 and 200?μmol?m?2?s?1 for the shade tolerant Picea abies seedlings and a level of around 200?μmol?m?2?s?1 for the more shade intolerant Pinus sylvestris seedlings.  相似文献   

12.
A historical outbreak of needle blight disease was recorded during 2018 to 2019 in plantations of Pinus radiata and Pinus nigra in the North of Spain. The main pathogens involved in this historical outbreak were identified as Lecanosticta acicola and Dothistroma septosporum. Recently, a variety of tree species in three arboreta planted between 2011 and 2013 in the Basque Country as part of the European project REINFFORCE were showing symptoms of needle blight and defoliation. The aim of this study was to determine which pine species were affected with these pathogens. Tree species sampled included several provenances of P. brutia, P. elliottii, P. nigra, P. pinaster, P. pinea, P. ponderosa, P. sylvestris and P. taeda. Using molecular identification methods, Lecanosticta acicola was confirmed infecting Pinus brutia (Provenance: Alexandropolis, Greece and var. eldarica, Crimea) and represents a new host species for this pathogen. Pinus elliottii (Provenance: Georgia, USA) and P. ponderosa (Provenance: Central California, USA) are new host reports of L. acicola for Spain. Dothistroma septosporum was found for the first time on P. brutia (Provenance: Marmaris, Turkey) and P. ponderosa (Provenance: Oregon, USA) in Spain and was also detected infecting P. nigra (Provenance: Sologne Vayrières, France).  相似文献   

13.
The aim of this study is to determine the competing regeneration and expansion patterns of two co-occurring pine species (Pinus brutia, Pinus nigra ssp. pallasiana), in a transitional montane Mediterranean zone. We measured the regeneration density of all woody species in 102 randomly located stands along an altitudinal gradient on the island of Lesbos, Greece. Individuals of pines were assigned to different size classes. Topographic factors (altitude, aspect, and soil depth) and light availability (through hemispherical photographs) were measured for each stand. Statistical analyses were applied to explore the effect of each factor on recruitment density of the competing pine species, and to elucidate patterns of interaction. Canopy openness was the most important parameter controlling the recruitment of P. brutia, while the regeneration density of P. nigra was mainly related to canopy openness and heat load. An idiosyncratic response of the recruitment vigour of the two species was identified along gradients of shade and drought stress. The decline in P. nigra recruitment density with drought conditions underlines threats to its population maintenance even in the absence of fire. On the other hand P. brutia seems to be a stronger invader in transitional zones. The studied species could be considered typical representatives of the two most widely distributed pine functional types across the Mediterranean basin, and our results agree with the theoretical ability of such species to maintain and expand their populations.  相似文献   

14.
With this study we investigated the effective factors on annual amount of total litterfall and needle litterfall in Pinus brutia forests and estimated them with a regression model based on certain stand parameters. We studied 27 permanent plots representing different stand structure and environmental conditions in South-Western Turkey. Litterfall was collected in three month intervals corresponding to each of four seasons for a three-year period. We found a significant relationship between litterfall and stand properties such as crown closure (%), basal area (m2?ha?1), stand stem volume (m3?ha?1), above-ground biomass (t?ha?1), mean annual volume increment (m3?ha?1?yr?1) and site index (T?=?75). Similar relationships also hold true between litterfall and each of such climatic factors as seasonal mean temperature (°C), relative humidity (%) and temperature/precipitation ratio (dimensionless). The mean annual litterfall considerably varied depending on stand characteristics and certain environmental factors. Both needle litterfall and total litterfall may be predicted for long term by regression models using certain stand parameters. Models developed for litterfall of P. brutia forests in this study may be used for national C inventory in Turkey.  相似文献   

15.
Traditionally, poplar (Populus spp.) have been planted to control erosion on New Zealand’s hill-slopes because of their capacity to dry out and bind together the soil. Two systems: (1) widely spaced, planted poplar for soil conservation, and (2) non-eroded open pasture were compared to determine the relative effect of the poplar–pasture system on the production, nutritive value and species composition of the pasture, and on the water balance. Measurements were made at three sites with mature poplar (>29 years and 37–40 stems ha−1) and at a replicated experiment with young poplar (5 years, 50–100 stems ha−1). Soil water relations did not suggest strong competition for water between poplar and pasture. Pasture accumulation under mature poplar was 40% less than in the open pasture, but under young poplar was similar to that in the open pasture. Chemical composition of pasture suggested that feed quality of pasture in the open was better than under the poplar canopy, except during spring, when most chemical components were similar. At the most, in vitro digestibility of pasture dry matter was 8.9% lower and metabolisable energy of pasture dry matter was 1.5 MJ kg lower under the poplar canopy than in the open pasture. Shade tolerant species were not dominant in the plant community under the poplar canopy with grasses such as browntop (Agrostis capillaris, L.) and ryegrass (Lolium perenne, L.) being a high proportion of the plant community. Differences in chemical composition were related to differences in the botanical composition between the open pasture and the poplar understorey. It was concluded that the greatest effect of poplar was on pasture production due to shading, and that management of this silvopastoral system needs to focus on control of the tree canopy to lessen the decrease in pasture production.  相似文献   

16.
17.
In a long-term study (1980 to 1993), the survival, growth performance and biomass production of two grass species viz. Chrysopogon fulvus (Spreng.) Chiov. and Eulaliopsis binata (Retz.) C.E. Hubb. were assessed when intercropped with four tree species viz. Albizia lebbek (L.) Benth., Grewia optiva Drumm., Bauhinia purpurea L. and Leucaena leucocephala (Lamk.) de Wit. on the bouldery riverbed lands of Doon Valley of north-west India. The survival of grass clumps was higher under the canopy of B. purpurea (48.3% in 1993 of the initial planting density of 20,000 clumps ha−1 in 1980) and G. optiva (47.4%) than of L. leucocephala (31.1%) and A. lebbek (29.4%), and at 75% intensity of tree lopping (40.9%) than at 50% (37.1%). The effect of tree species on different growth parameters of grasses was not uniform, with G. optiva and B. purpurea causing comparatively more synergistic effect on clump height and clump diameter respectively. Although the performance of grasses was good under A. lebbek and L. leucocephala in the early years (1980--1987), these tree species resulted in the lowest grass dry weight in the later years up to 1993. The beneficial effect of higher lopping intensity of 75% was observed on the growth and biomass production of grasses over 50% lopping, presumably due to increased light penetration into the under-storey. The biomass production of grasses reached a maximum at four years of growth in 1983, after which, it decreased gradually to less than half in 1993. Eulaliopsis binata showed higher survival, growth and biomass production than C. fulvus throughout the period of study. The total biomass production was highest in association with B. purpurea followed by G. optiva, which appeared to be the most suitable tree species along with E. binata for sustainable silvopasture development on the marginal lands of Doon Valley of north-west India. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

18.
The objective of this study was to evaluate how competition would affect the physiology, and thus productivity of American beautyberry (Callicarpa americana L.), wax myrtle [Morella cerifera (L.) Small] and inkberry [Ilex glabra (L.) A. Gray] when intercropped in a longleaf pine (Pinus palustris Mill.) plantation in the southeastern United States. The effect of competition was assessed via comparisons of mortality, biomass, light transmittance, gas exchange and soil moisture between intercropping and monoculture (treeless) treatments. Overall, shrubs in the intercropping treatment performed worse than those in the monoculture, with higher mortality, and reductions in biomass of 75.5, 50.6, and 68.7% for C. americana, M. cerifera and I. glabra, respectively. Root–shoot ratios for all species were significantly higher and soil moisture during dry periods was significantly lower in the intercropping treatment. Light transmittance below the pine canopy was high (57.7%) and I. glabra was the only species that exhibited reduced A max when belowground resources were not limiting. These results suggest that the effect of shading is minimal and belowground competition is likely the most important determinant of productivity in this system.  相似文献   

19.
The need for shade tolerant forage species for forested grazing lands of the Southeastern United States has been recognized for some time. Introduced grasses and temperate legumes have been evaluated for this use with some success. Sparse stands of native legumes occur throughout these woodlands. The potential value of these native legumes has received little attention. Seedlings of Galactia elliottii Nuttall, a widely occurring native legume in the pine flatwoods (Spodosols), were established in pots and subsequently evaluated for growth response to shade levels of 0, 25, 55, 75, and 92% under vinyl shade cloth. Maximum herbage yield and maximum nitrogen yield after a 60-day growth period were obtained under 25% shade. Responses of herbage yield, percent nitrogen, and nitrogen yield to shade were described by quadratic equations with initial increases followed by decreases as shade increased. A second experiment involving small plots of G. elliottii in dense bahiagrass (Paspalum notatum Flugge) sod produced negative linear relationships between shade and yield of each forage species. However, G. elliottii yield declined at a slower rate than bahiagrass. These results indicate that G. elliottii is adapted to shaded flatwoods environments and suggest that further efforts to evaluate local woodland legumes for forage potential could provide productive species for reseeding shaded woodland sites in the Southeastern United States.This article is Florida Agricultural Experiment Station paper number 7831.  相似文献   

20.
The aim of the study was to investigate dynamics and pattern of natural regeneration and the influence of seedbed and light on germination and initial seedling survival of Scots pine (Pinus sylvestris L.) during three growing seasons. Four 5-m2 plots in a natural Scots pine forest in central Spain were randomly established at the beginning of the regeneration process. Germination and seedling survival were recorded in 100 regeneration sampling subplots (0.25 m2) per plot, while seedbed type and the relative light intensity reaching the forest floor was characterised in 1-m2 subplots. The spatial correlations between survival, light conditions and organic matter depth were analysed through cross-variograms. Germination and survival were highly variable both within and between plots (ranging from 0 to 89%) and affected by high summer temperatures (33–35°C) in 2003. The spatial pattern characterisation of survival by Ripley’s K function showed a dominant cluster distribution. Occurrence tended to be clumped when abundance was greater than 15 seedlings, whereas for lower densities, seedlings were randomly distributed. Seedlings and herbs occupied the same sites where environmental conditions were appropriate for them to live. Spatial association occurred frequently for light and organic matter depth. Results suggested that the Scots pine seedlings in our study in central Spain preferred moderate light conditions (Global Site Factor <0.40). Thus, if this forest is to be naturally regenerated with Scots pine, the shelterwood system (whereby some mother trees are left to provide shelter for at least 5 years), along with mechanical disturbance of the seedbeds, would promote seed germination, as long as a seed source is present. However, regeneration success is affected by year-to-year conditions.  相似文献   

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