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种子是更新造林的物质基础。建立林木种子园需要较长的时间才能见效,所以搞好人工林改造为母树林的工作尤为重要。 相似文献
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Helton N. Souza Irene M. Cardoso José M. Fernandes Flávia C. P. Garcia Verônica R. Bonfim Alvori C. Santos Anôr F. Carvalho Eduardo S. Mendonça 《Agroforestry Systems》2010,80(1):1-16
A challenge in establishing agroforestry systems is ensuring that farmers are interested in the tree species, and are aware
of how to adequately manage these species. This challenge was tackled in the Atlantic Rainforest biome (Brazil), where a participatory
trial with agroforestry coffee systems was carried out, followed by a participatory systematisation of the farmers experiences.
Our objective was to identify the main tree species used by farmers as well as their criteria for selecting or rejecting tree
species. Furthermore, we aimed to present a specific inventory of trees of the Leguminosae family. In order to collect the
data, we reviewed the bibliography of the participatory trial, visited and interviewed the farmers and organised workshops
with them. The main farmers’ criteria for selecting tree species were compatibility with coffee, amount of biomass, production
and the labour needed for tree management. The farmers listed 85 tree species; we recorded 28 tree species of the Leguminosae
family. Most trees were either native to the biome or exotic fruit trees. In order to design and manage complex agroforestry
systems, family farmers need sufficient knowledge and autonomy, which can be reinforced when a participatory methodology is
used for developing on-farm agroforestry systems. In the case presented, the farmers learned how to manage, reclaim and conserve
their land. The diversification of production, especially with fruit, contributes to food security and to a low cost/benefit
ratio of agroforestry systems. The investigated agroforestry systems showed potential to restore the degraded landscape of
the Atlantic Rainforest biome. 相似文献
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Daniel G. Manson Susanne Schmidt Mila Bristow Peter D. Erskine Jerome K. Vanclay 《Agroforestry Systems》2013,87(1):233-250
Mixed species plantations using native trees are increasingly being considered for sustainable timber production. Successful application of mixed species forestry systems requires knowledge of the potential spatial interaction between species in order to minimise the chance of dominance and suppression and to maximise wood production. Here, we examined species performances across 52 experimental plots of tree mixtures established on cleared rainforest land to analyse relationships between the growth of component species and climate and soil conditions. We derived site index (SI) equations for ten priority species to evaluate performance and site preferences. Variation in SI of focus species demonstrated that there are strong species-specific responses to climate and soil variables. The best predictor of tree growth for rainforest species Elaeocarpus grandis and Flindersia brayleyana was soil type, as trees grew significantly better on well-draining than on poorly drained soil profiles. Both E. grandis and Eucalyptus pellita showed strong growth response to variation in mean rain days per month. Our study generates understanding of the relative performance of species in mixed species plantations in the Wet Tropics of Australia and improves our ability to predict species growth compatibilities at potential planting sites within the region. Given appropriate species selections and plantation design, mixed plantations of high-value native timber species are capable of sustaining relatively high productivity at a range of sites up to age 10 years, and may offer a feasible approach for large-scale reforestation. 相似文献
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Trade-offs analysis for possible timber-based agroforestry scenarios using native trees in the Philippines 总被引:1,自引:2,他引:1
To assess possible new agroforestry scenarios the tree–soil–crop interaction model in agroforestry systems (WaNuLCAS 3.01)
was used based on-site specific data collected from Tabango (Central Philippines). Three native timber trees (Shorea contorta Vid., Pterocarpus indicus Juss., and Vitex parviflora Willd.) and one widely spread exotic specie (Swietenia macrophylla King.) were simulated under different intercrop scenarios with maize (Zea mays L.) and subsequently compared. Model simulation results quantified and explained trade-off between tree and crop. For example,
higher tree densities will lead to a loss of crop yield that is approximately proportional to the gain in wood volume. However,
beside this trade-off effect, there is considerable scope for tree intercropping advantage under a fertilization scenario,
with systems that yield about 50% of the maximum tree biomass still allowing 70% of monoculture maize yield. Maximum tree
yield can still be obtained at about 20% of the potential crop yield but intermediate tree population densities (400 trees ha−1) and the resulting larger stem diameters may be preferable over the larger total tree biomass obtained at higher tree densities.
Another advantage from intercropping systems is that trees directly benefit from the inputs (i.e., fertilizer) that are applied
to the crops. The three native trees species studied have different performance in relation to productivity but are similar
to (or even better than) S. macrophylla. 相似文献
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J. Roux R. N. Heath L. Labuschagne G. K. Nkuekam M. J. Wingfield 《Forest Pathology》2007,37(5):292-302
Ceratocystis albifundus causes the disease known as wattle wilt of non‐native Acacia mearnsii trees in South Africa, Uganda and Kenya. Infection results in rapid wilt and death of susceptible trees and stem cankers on more tolerant trees. It has been suggested that C. albifundus is indigenous to southern Africa, possibly having spread from native Protea spp. to non‐native A. mearnsii and A. decurrens trees. Although C. albifundus has been collected from Protea spp., these reports are based on limited records for which only aged herbarium specimens exist. During surveys of wound‐infecting fungi on native tree species in South Africa, a fungus resembling C. albifundus was collected from Protea gaguedi, Acacia caffra, Burkea africana, Combretum molle, C. zeyheri, Faurea saligna, Ochna pulchra, Ozoroa paniculosa and Terminalia sericea. The identity of the fungus was confirmed as C. albifundus, using comparisons of DNA sequence data for the ITS and 5.8S gene of the rRNA operon. In pathogenicity trials, lesions were produced on C. molle and A. caffra, with some trees beginning to die at the termination of the experiment. This study represents the first report of C. albifundus from native tree species in South Africa and provides unequivocal evidence that the fungus occurs naturally on native Protea spp. The wide host range of C. albifundus, as well as its abundance on these indigenous hosts lends further support to the view that it is a native African pathogen. 相似文献
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A survey to identify ophiostomatoid fungi that infect wounds on native Norwegian and Swedish broadleaved trees was undertaken during summer 2004. A fungus resembling a species of Sporendocladia was commonly isolated from the exposed cambium and inner bark of wounds. Morphological examination and comparisons of DNA sequence data for the ITS and 5.8S regions of the rRNA gene region led to its identification as Sporendocladia bactrospora. Pathogenicity trials on young Populus tremula and Betula pubescens trees showed that S. bactrospora is capable of causing lesions on these trees. There have been few previous reports of S. bactrospora, and in most cases, these have been as saprophytes on wood. In contrast, results of this study show that it is a common inhabitant of freshly made wounds on native broadleaved trees in Scandinavia, and it appears to contribute to staining of wood. 相似文献
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Thomas SC 《Tree physiology》2011,31(11):1161-1163
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Latitudinal shifts in tree species distributions are a potential impact of climate change on forest ecosystems. It has been hypothesized that some tree species may become extirpated as climate change effects may exceed their migration ability. The goal of this study was to compare tree species compositions in northern urban areas to tree compositions in forestland areas in the eastern U.S. as an indicator of the potential for urban trees to facilitate future forest tree species migration. Results indicated that a number of tree species native to eastern U.S. forests of southern latitudes are currently present in northern urban forests. The biomass density (Mg/ha) of urban tree species is typically less than half of forestland densities with the majority of urban tree species found in nearby (<100 km) forestland. Urban tree propagation is often facilitated by humans, whereas the necessary pollinators and agents of tree seed dispersal in forestlands may be lacking regardless of climate change. It is suggested that urban areas may serve divergent, dual roles as both a native tree seed source and refuge for a limited number of forestland tree species, but also a facilitator of non-native tree invasion. 相似文献
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Prunus cerasoides D. Don has been identified as a framework species for restoring evergreen forest in seasonally dry climates. The aim of this study was to develop criteria to select parent trees for supplying seed to forest restoration projects based on seedling performance in the nursery and in the field. Seed progenies were collected from 50 individual parent trees; 13 in Doi Inthanon National Park; 14 in Doi Ang Khang; and 23 in Doi Suthep-Pui National Park. Criteria were developed for the selection of superior parent seed trees based on nursery and field performance, and a provisional selection of parent seed trees for forest restoration projects has been made based on these criteria. Four standards for selection of superior seed trees were recognised: (i) 70% or greater seedling survival in the field, (ii) a seedling height of 100 cm or taller after the first growing season in the field, (iii) 40% or greater germination in the nursery and (iv) 70% or higher seedling survival in the nursery. Twenty one seed trees met these standards. 相似文献
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D.M. Newbery M. LingenfelderK.F. Poltz R.C. OngC.E. Ridsdale 《Forest Ecology and Management》2011,262(12):2095-2107
At Danum Valley, Sabah, dipterocarp forest is affected by moderately-strong droughts which perturb the ecosystem. Analysing stem growth for c. 3700 understorey trees (12.5-<50 cm girth), measured over four periods (between 1986 and 2007), response to an ENSO-related event (1998) was followed. Relative growth rates (rgr) of the 48 most abundant species in the size class were considered individually, and as relative changes between periods. From them a measure reactivity was derived. Whilst a third of species differed from one another in rgr, within-species rates were highly variable: often species had very different (pluralistic) response patterns over time. The rgr decreased in the drought period, increased and overcompensated directly afterwards, and later returned to original levels. The forest displayed moderate resistance, and high resilience and stability within c. 4 years of the perturbation. Oscillatory responses were more pronounced among true understorey species than among small trees of overstorey ones, suggesting that the former might play a key role in stabilization. Environmental stochasticity in the form of coloured noise may therefore be causing a major part of the variation in rain forest dynamics and explain its complexity. 相似文献
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Ângela Maria Quintão Lana Regina Maria Quintão Lana Ernane Miranda Lemes Guilherme Lanna Reis Gustavo Henrique Ferreira Abreu Moreira 《Agroforestry Systems》2018,92(2):415-424
Silvopastoral systems (SPSs) are considered a conservationist system by combining forestry species cultivation with domesticated grazing animals, intercropping trees, and pasture in the same area. SPSs are noun for its contribution to improve soil chemical and physical properties, enhance grass nutritional status, provide healthier animal environment, and increase farmers’ options to maximize the use of land. In soil degraded areas, such as those found in Brazilian savannah biome (BSB), the SPSs constitute an alternative to soil recuperation in these areas. Therefore, our aim was to assess soil fertility attributes at different depths on a BSB grown with Brachiaria brizantha cv. Marandu grass, the influence of SPS with native tree zeyheria (Zeyheria tuberculosa) settled in 1984, or with the exotic eucalyptus (Eucalyptus grandis) settled in 1994. The soil water pH, P, Ca, Mg, and K contents, as well as soil base sum and saturation, were found superior mostly at the top layer (0–2 cm) of the eucalyptus site, than for the ipê-felpudo site. This response was correlated to greater soil organic matter and carbon at the eucalyptus site, which demonstrated to have high nutrient cycling rates. Around 50 % of the CEC in both SPSs was occupied by bases, demonstrating that the areas have large potential to absorb applied nutrients. The SPSs have no significant impact on S-SO4 2? or micronutrient availability. The litter composition in eucalyptus site was accountable for the superior results of this SPS, which has shown as a promising choice for land use and conservation in the BSB. 相似文献