Twelve-week-old container-grown seedlings of noble fir (Abies procera Rehd.) and Shasta red fir (A. magnifica A. Murr. var. shastensis Lemm.), both high-elevation species, were grown under controlled environments in a study of induction of terminal-bud dormancy. Eight treatment combinations of long (15 h) or short (11 h) photoperiods, warm (25°/20°C) or cool (18°/12°C) thermoperiods, and dry (–1.2 MPa) or wet (–0.6 MPa) moisture regimes were imposed upon seedlings for 12 weeks. Treatment factors significantly affecting the induction of dormancy in terminal buds of seedlings were identified over time. The results suggest that seedlings responded dynamically to dormancy cues. The warm/dry and cool/wet combinations induced dormancy in the first 2 weeks in noble fir and in the first week in Shasta red fir. Short-day/warm and long-day/cool combinations enhanced dormancy induction in weeks 3 to 4 in noble fir and in weeks 1 to 7 in Shasta red fir. Short days and cool thermoperiods independently hastened dormancy induction in noble fir in weeks 5 through 12. 相似文献
In this paper we report the results of a study on the suitability of the dehesa (Mediterranean woodlands) as habitat of red deer (Cervus elaphus hispanicus) in a closed country estate of about 4300 ha total surface situated in the San Pedro Mountain, in Central Extremadura, Spain. We have described the deer management with respect to habitat, exploitation mode, deer feeding, population control and production of goods and services. It is concluded that the dehesa system is a rich natural resource that preserves and improves the degraded environment.
Resumen En el presente trabajo se estudia la dehesa como hábitat del ciervo (Cervus elaphus hispanicus). Se ha tomado como referencia una finca cerrada de 4300 ha de ST situada en la Sierra de San Pedro, en Extremadura, España. Se describen los sistemas de gestión actuales del ciervo en cuanto a hábitat, modo de explotación, alimentación, control de población y producción de bienes y servicios. Concluyendo con la necesidad de fomentar este tipo de explotaciones cinegéticas de dehesa que ayudan a conservar y potenciar el medio ambiente en zonas despobladas y deprimidas
Abbreviations CS
collected surface
- DMFCU
deedmixed feed cattle units
- Fi
final inventory
- FS
fertilized surface
- Ii
Initial inventory
- K
Potassium
- N
Nitrogen
- NBF
number of breeding females
- NBFIi
number of breeding females of initial inventory
- NBFR
number of breeding females released
- NBM
number of breeding males
- NBMIi
number of breeding males of initial inventory
- NBMR
number of breeding males released
- NCCR
number of captive calves released
- NCFi
number of calves of final inventory
- NCR
number of calves released
- NFR
number of female renovation
- NYMR
number of young males released
- NYFR
number of young females released
- P
phosphorus
- PP
permanent Pastures
- pts
pesetas
- QS
Quercus stalks
- RDED
resources directly eaten by deer
- SPOM
selected hunted down poor quality males
- SS
sowed surface
- TN
total needs of deer
- TNR
total number released
- UAS
useable agrarian surface
- WB
wooded brush
- WQS
wooded Quercus surface
- WS
wooded surface 相似文献
Eight woody fodder species adapted to the highlands of Rwanda were evaluated in terms of dry matter intake in one experiment. Animals were offered a daily diet comprising 4.0 of fresh matter of Setaria splendida grass supplemented with or without one of the eight fodder species tested. In all cases, total daily feed intake was increased by the addition of woody fodder. Daily intake of the woody fodder was high for Acacia koaia, Mimosa scabrella and Acacia koa at 43.7, 42.6 and 41.9 g/kg BW0.75, respectively. The dry matter intake of the other five species (Alnus acuminata, Chamaecytisus palmensis, Hagenia abyssinica, Acacia mearnsii and Acacia melanoxylon) ranged from 18.9 to 30.1 g/kg BW0.75 per day. In another experiment, a basic daily diet of 4.0 kg of fodder (in fresh weight) was given to each animal. This ratio comprised S. splendida supplemented with M. scabrella and incorporated at 0 (control), 45% and 66% (fresh weight basis) of the total daily diet. Improved weight gain was obtained when setaria was supplemented with M. scabrella with daily weight gain of 31, 47 and 51 g/animal for 0, 45 and 66% M. scabrella, respectively. 相似文献
A multidisciplinary team undertook a six-year investigation on the agro-ecological and socio-economic aspects of the dehesa system in the Sierra Norte area, a part of the Sierra Morena of the Sevilla Province, Western Andalusia, Spain. This paper summarizes its findings on the various agro-ecological features of the system and evaluates the system's functional aspects vis-a-vis the trends and developments in land use in the region over the past few centuries. The synergistic effects of tree cover on understorey grassland vegetation is discussed in terms of soil fertility build-up and favourable micro-climatic and hydrological features, and the potential use of this information in future research and development programmes to improve the dehesa system in the Mediterranean region is outlined. 相似文献
Relatively little is known about soil organic carbon (SOC) dynamics in montane ecosystems of the semi-arid western U.S. or the stability of current SOC pools under future climate change scenarios. We measured the distribution and quality of SOC in a mosaic of rangeland-forest vegetation types that occurs under similar climatic conditions on non-calcareous soils at Utah State University's T.W. Daniel Experimental Forest in northern Utah: the forest types were aspen [Populus tremuloides] and conifer (mixture of fir [Abies lasiocarpa] and spruce [Picea engelmannii]); the rangeland types were sagebrush steppe [Artemisia tridentata], grass-forb meadow, and a meadow-conifer ecotone. Total SOC was calculated from OC concentrations, estimates of bulk density by texture and rock-free soil volume in five pedons. The SOC quality was expressed in terms of leaching potential and decomposability. Amount and aromaticity of water-soluble organic carbon (DOC) was determined by water extraction and specific ultra violet absorbance at 254 nm (SUVA) of leached DOC. Decomposability of SOC and DOC was derived from laboratory incubation of soil samples and water extracts, respectively.
Although there was little difference in total SOC between soils sampled under different vegetation types, vertical distribution, and quality of SOC appeared to be influenced by vegetation. Forest soils had a distinct O horizon and higher SOC concentration in near-surface mineral horizons that declined sharply with depth. Rangeland soils lacked O horizons and SOC concentration declined more gradually. Quality of SOC under rangelands was more uniform with depth and SOC was less soluble and less decomposable (i.e., more stable) than under forests. However, DOC in grass-forb meadow soils was less aromatic and more bioavailable, likely promoting C retention through cycling. The SOC in forest soils was notably more leachable and decomposable, especially near the soil surface, with stability increasing with soil depth. Across the entire dataset, there was a weak inverse relationship between the decomposability and the aromaticity of DOC. Our data indicate that despite similar SOC pools, vegetation type may affect SOC retention capacity under future climate projections by influencing potential SOC losses via leaching and decomposition. 相似文献