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1.
The Sierra Madre del Sur, Oaxaca is considered an area with high diversity of ecosystems, and low levels of fragmentation due to human disturbance. An indigenous people, the Zapotecs, have inhabited this area for centuries and Zapotec communities have used and continue to make use of local resources for their subsistence. Agroforestry systems provide timber, firewood, and non-timber forest products to local communities. Despite the ecological and cultural relevance of this region, basic information about local practices of management and harvesting are lacking. Little is known about the possible effects of these practices on biodiversity conservation. The objectives of this study were: to determine the local uses of forest wood resources in the municipality of San Agustín Loxicha, to determine the tree species most used by the inhabitants of this municipality and to discuss the implications of this management in the conservation of plant cover in this Priority Terrestrial Region. The reported main use of tree species was firewood, obtained by gathering dry branches and bark, as well as by felling dead trees. To a lesser extent, tree species are used to build houses and make furniture. Local people collect trees from the surrounding vegetation, so the richness and abundance of tree species in the area surrounding each community will always influence the ability of the communities to meet their needs. These practices do not have drastic effects on plant cover, mainly in areas of established forests. These traditional practices are involved in an empirical strategy to conserve and manage local resources.  相似文献   

2.
Tree plantations of native and exotic species are frequently used to compensate for forest loss in the tropics. However, these plantations may support lower species diversity and different communities than natural forest. We therefore investigated bird communities in stands of natural forest, different types of tree plantations and secondary forest in Kakamega Forest, western Kenya. We compared birds differing in habitat specialisation, i.e. forest specialists, generalists, and visitors. We recorded significant differences in mean species richness and number of individuals among the different forest types. Stands of natural forest and plantations of indigenous tree species comprised more species and individuals than plantations of exotic tree species and secondary forest. This was caused by a significant decline of forest specialists and generalists from natural forest and indigenous plantations to exotic plantations and secondary forest. Species composition of the bird communities did not differ between natural forest stands and plantations of a mixture of indigenous tree species, but clearly changed between natural forest and plantations of single tree species. These findings demonstrate that natural forest areas are needed for the conservation of forest bird diversity, but that plantations with a mixture of indigenous tree species can have similarly high conservation value.  相似文献   

3.
Community forestry is expanding in developing countries but there is limited knowledge of, and contradictory findings about, its contribution to biodiversity conservation. This study aims at increasing the understanding of tree species diversity in community forests compared to National Parks. A forest inventory was carried out in four community forests and one National Park in the mid-hills of central Nepal. The study found that community forestry has contributed to high tree species diversity where forest management communities have interests in multiple species, but most community forests are moving toward promoting limited timber yielding species that have high economic value. Linking community forestry with economic incentives for conserving multiple tree species could therefore be a strategy to conserve biodiversity outside of protected areas.  相似文献   

4.
森林植物群落多样性与虫害自然控制力的研究进展   总被引:1,自引:0,他引:1  
讨论了森林植物群落多样性与森林虫害自然控制力间的关系,阐明了森林虫害自然控制力有随森林植物群落多样性的升高而增强的趋势.并认为森林虫害自然控制力的本质是森林植物群落多样性的生态系统功能.初步提出了通过合理地提高森林植物群落多样性来提高森林虫害自然控制力的主张及提高森林虫害自然控制力的几种具体途径,即合理的乔木物种混交;引进和保留乡土的草本、灌木物种;提高生态系统水平的生物多样性;避免营造大面积的人工纯林.  相似文献   

5.
Defining the spatial arrangement and length of the cutting cycle in a logged area is crucial for reconciling potential conflicts between timber yields and maintenance of ecosystem services in natural forests. In this study, we investigated long-term impacts of clear-fell logging on timber production and tree species diversity in a subtropical forest on the Ryukyu Islands, using an individual-based simulation model. We assumed six logging scenarios defined by combinations of forest type and regeneration processes, which acted as surrogates for spatial scales of clear-fell logging. These scenarios were simulated under cutting cycles ranging from 20 to 150 years. Short-cutting cycles resulted in dominance by the sprouting species Castanopsis sieboldii. The compositional shift was accelerated by the lack of seed dispersal from surrounding forest areas. The simulations demonstrated that a sustainable logging regime maintaining both yield and tree species diversity requires a cutting cycle longer than 50 years. The simulation results also suggest that the trade-off between the recovery of tree species diversity and timber production is favored more in stands surrounded by mature forest than in isolated stands or stands surrounded by immature forest. Ecological risk assessments based on model simulations provide an alternative to current forest management practices that rely on empirical knowledge.  相似文献   

6.
To examine the relationship between forest succession following fire and the composition of bird communities, we investigated the vegetation structure, bird population density, foraging behavior and guild structure in bamboo grasslands (11 years since the last fire), pine savanna (41 years), pine woodland (58 years), old-growth hemlock forest (never burned), and old-growth spruce forest (never burned) in the Tatachia area of central Taiwan. Canopy height, total foliage cover, tree density, total basal area of tree, total basal area of snags, foliage height diversity, and tree species richness all increased with successional age. However, shrub cover peaked in intermediate successional stages. The vertical profile of foliage cover was more diverse in later successional forests, which had more breeding bird species and ecological guilds. All the breeding bird species recorded in early and intermediate stages were also found distributed in the late successional forests. Because Taiwan has high precipitation and humidity, and most forest fires in Taiwan are caused by human activities, forest fires and large areas of early successional vegetation were probably rare in the mountain areas of Taiwan prior to the arrival of humans. Therefore, bird species have not had enough time to adapt to areas with early or intermediate successional vegetation. Moreover, late successional forests host all the major plant species found in the early and intermediate stages and have higher foliage height diversity index, which was positively correlated with the bird species richness and bird species diversity index in this study. As a result, all breeding bird species and guilds in the area can be found in late successional forests. Efforts for conserving avian diversity in Taiwan should focus on protecting the remaining native old-growth forests.  相似文献   

7.
Non-coniferous vegetation, including herbs, shrubs, and broad-leaved trees, makes a vital contribution to ecosystem function and diversity in Pacific Northwest conifer forests. However, forest management has largely been indifferent or detrimental to shrubs and trees that have low commercial value, in spite of a paradigm shift towards more holistic management in recent decades. Forest management practices that are detrimental to broad-leaved trees and shrubs are likely to decrease habitat diversity for wildlife, but the number of species that may be affected has not previously been enumerated. I reviewed life history accounts for forest-dwelling vertebrate wildlife species and derived a list of 78 species in Oregon and Washington that are associated with non-coniferous vegetation. The diversity of direct and indirect food resources provided was the primary functional basis for associations of most species with non-coniferous vegetation. Thus, a diversity of herbs and broad-leaved trees and shrubs provides the foundation for food webs that contribute to diversity at multiple trophic levels in Pacific Northwest conifer forests. Given the number of species associated with non-coniferous vegetation in conifer-dominated forests, maintaining habitats that support diverse plant communities, particularly broad-leaved trees and shrubs, will be an important component of management strategies intended to foster biodiversity. Silvicultural practices such as modified planting densities, and pre-commercial and commercial thinning, can be used to control stand density in order to favor the development of understory herbs, shrubs, and a diversity of tree species within managed stands. Allowing shrubs and hardwood trees to develop and persist in early seral stands by curtailing vegetation control also would benefit many species associated with non-coniferous vegetation.  相似文献   

8.
High Andean cloud forests are home to a diversity of unique wildlife and are important providers of ecosystem services to people in the Andean regions. The extent of these cloud forests has been widely reduced through conversion to pasture for livestock, which threatens the forests’ ability to support biodiversity and provide ecosystem services. This paper explores whether impacts on woody plant biodiversity and four ecosystem properties (woody plant species richness, juvenile timber tree abundance, soil organic matter content and soil moisture) from converting forest to pasture can be mitigated if some woody forest vegetation is maintained within pastures. Woody vegetation in pastures was found to conserve those woody plant species that are more tolerant to exposure and grazing, but conservation of the high montane cloud forest community required areas of forest from which livestock were restricted. The sampled sites clustered according to woody plant species cover; these clusters represented a gradient from pasture with patches of shrubs to mature forest. Clusters differed in both woody plant species richness and number of juvenile timber trees whereas soil organic matter and soil moisture were observed to be similar among all clusters. This suggests that the different habitats may have some equivalent ecosystem properties. We conclude that the presence of woody vegetation in pastures may reduce some of the impacts of converting forest to pasture, but should not be considered a substitute for protecting large areas of forest, which are essential for maintaining woody plant species diversity in high Andean cloud forest.  相似文献   

9.
The joint and independent effects of dominant tree species, forest patch spatial attributes, and forest structure and management as drivers of plant species richness and composition in small forest patches scattered within an intensive agricultural landscape were addressed.In a landscape with scattered urban and intensive dairy agricultural areas in north-west Portugal, within which small forest patches (dominated by pines, eucalypts, or both) represent semi-natural habitat islands, 50 small forest patches, with areas ranging between 0.3 and 3 ha, were selected and surveyed for vascular plant diversity, within dairy farming landscape mosaics dominated by annual forage crops. Explanatory variables were composed of three datasets derived either from GIS mapping or field observations: forest type (dominant tree species), forest patch spatial attributes (patch area and shape index), and measures of forest management and structure (diameter at breast height, tree density per hectare, and percentage cover of vegetation strata). Variations in these forest patch attributes were assessed across forest types, and related to measures of plant diversity (total, native, alien, woody, and herbaceous species richness). Redundancy analysis with variance partitioning was applied to evaluate the joint and independent effects of the three sets of variables on species assemblages. The recent shift in canopy dominance from pine to eucalypt observed in the region appears to be related to a (nonsignificant) tendency for the increase of patch area and to the decrease of patch complexity, as well as several changes in forest structure and management, expressed as a trend to denser tree canopies and lower cover of understory plants. Dominant tree species and attributes related to forest structure and management were the most important factors determining plant diversity. The joint effect of the dominant tree species and forest structure and management resulted in lower levels of plant species richness in eucalypt plantations. These were also more prone to invasion by alien species, probably due to decreased biotic resistance from unsaturated native plant assemblages. Our results draw attention to the importance of dominant tree species and management practices for the maintenance of plant diversity levels (species richness and composition) in dairy landscape mosaics, highlighting the importance of the remnants of semi-natural forests as refuges for plant diversity in the landscape context. Nonetheless, forest plant diversity could further be fostered by promoting naturalness of pine stands and the regeneration of native oak woodlands in some forest areas. This would also diversify the range of ecosystem services that could be provided by forest areas in these peri-urban farmlands.  相似文献   

10.
To halt biodiversity loss in the humid tropics of developing countries, it is crucial to understand the roles and effects of human-modified landscapes with fragmented forest remnants in maintaining biodiversity while fulfilling the demands of local communities and reducing poverty. To implement appropriate landscape planning for conserving biodiversity and ecosystem functioning, appropriate information is required about parameters of habitat suitability among various anthropogenic habitats with a range of distances to forests and vegetation characteristics, but such information is limited. We examined differences in avian communities between a remnant forest and four types of man-made forest (two mature plantations and two agroforests) in a forest–agricultural landscape of West Java, and we analyzed the effects of both local and landscape factors on various types of species richness in this landscape. The results from non-metric multidimensional scaling revealed avifauna in the two types of agroforest was clustered separately from that in the remnant forest, mainly because drastic declines in the abundance of forest specialists (including IUCN red-listed species) and their replacement with open-habitat generalists. The mixed-tree agroforests were colonized by 30 % of forest specialists and forest-edge species found in the remnant forest, and maintained the highest richness of species endemic to Indonesia among man-made forests, implying that some forest specialists and endemics might have adapted to ancient landscape heterogeneity. High proportion of insectivorous birds was found in the remnant forest (more than 50 %) and drastically decline in man-made forests, although the species richness of insectivores did not decline significantly in broad-leaved plantations. We concluded that protection of remnant forests should be prioritized to conserve forest bird diversity. However, as different environmental factors affected the richness values of different ecological groups, appropriate landscape design and habitat management could improve functional diversity in forest–agricultural landscapes in the tropics.  相似文献   

11.
Gábor 《林业研究》2022,33(1):343-355
The biodiversity of natural or semi-natural native,old oak woodlands have high conservation impor-tance,especially in landscapes of monocultural forest plan-tations and arable fields.With a wider variety of microhabi-tats and foraging sources,such old oak forests can provide essential habitat for native forest bird communities.We con-ducted a study using bird point counts to compare the forest bird communities of old pedunculate oak (Quercus robur)remnants with native and non-native plantations in central Hungary in a landscape of mostly arable fields,settlements,and monocultural plantations.Avian surveys were carried out in old oak forest remnants,middle-aged oak,white pop-lar (Populus alba),hybrid poplar (Populus × euramericana),black locust (Robinia pseudoacacia),and pine (Pinus spp.)plantations.Fieldwork has been carried out in nine study sites,where all six habitat types were represented (with a few exceptions),to determine total abundance,species rich-ness,Shannon-Wiener diversity,species evenness,domi-nant and indicator species,and guild abundances.We found that old oak forest remnants were the most diverse habitats among the studied forest types,while hybrid poplar and pine plantations exhibited the lowest avian biodiversity.The avian guilds most sensitive to the loss of old oak forest remnants were ground foragers,bark foragers,cavity-nest-ers,residents,and Mediterranean migratory birds.Native habitats were more diverse than non-native plantations.Our results suggest that it is important to conserve all remaining high biodiversity old oak stands and to avoid clear-cutting of monocultural plantations in favour of practices such as mixed-species plantations,longer rotation lengths,or reten-tion forestry.  相似文献   

12.
Montados are silvo-pastoral systems, typical of the western Mediterranean Basin. When well managed, these ecosystems provide relevant ecosystem services and biodiversity conservation. In the northern part of the Mediterranean Basin, cork oak areas are mainly privately owned and a source of income to landowners, chiefly through cork and livestock production. Sustainable use is essential to maintain the ecological sustainability and socio-economic viability of these ecosystems. Biodiversity conservation and non-provisioning ecosystem services may generate additional incentives promoting sustainable use and conservation of montados, but require adequate mapping and identification. The high conservation value forest (HCVF) framework allows systematic inventory of biodiversity and non-provisioning ecosystem services and is widely applied in forest ecosystems. Here we exemplify the application of HCVF to the cork oak landscape of southern Portugal using a WebGIS tool that integrates the HCVF framework, in conjunction with Pareto optimization, to identify areas important for the conservation of biodiversity and ecosystem services. We present a case study using threatened bird and reptile species, as examples of biodiversity attributes, and carbon storage and water recharge rate of aquifers, as examples of ecosystem services attributes. We identify those areas in a cork oak landscape of southern Portugal where biodiversity and ecosystem services attributes are optimized. These areas can be prioritized for implementing conservation mechanisms, such as payment for ecosystem services, to promote sustainable forest management.  相似文献   

13.
Key factors causing the difference of wildlife populations in natural and managed forests are an important field of ecosystem and biodiversity research. To explore the factors contributing to bird-community features in the poorly studied European natural hemiboreal forests, we carried out a comparative study in old-growth and mature stands of five site types in Estonia. The mature stands were of clear-cut origin and managed for timber production. Old-growth hosted both more diverse and more abundant bird communities than mature stands, which does not support the putative ‘old-growth syndrome’ (high diversity at a low density) described previously in temperate Europe. Site-type specificity of bird communities was also more pronounced in old-growth, indicating a timber-harvesting induced process of biotic homogenization. In particular, natural swamp forests had characteristic bird species and those communities may be additionally sensitive to artificial drainage. In terms of invertebrate food supply, the availability of snails, rather than of insects, was related to bird-community characteristics; however, the influence of snails was due to one snail-poor forest type (Vaccinium type pine stands), not management. The abundance of coarse woody debris was the main structural feature affecting bird communities; tree-size variation was additionally important for species richness. A significant unexplained ‘old-growth’ effect remained even after the variables describing food supply and stand structure were taken into account. Our results imply the distinct importance of old-growth of different site types for hemiboreal bird communities. However, we did not obtain any evidence of different key factors structuring the bird communities in old-growth and mature stands.  相似文献   

14.
大围山国家级自然保护区是云南省最重要的保护区之一,生物多样性的管理十分重要。研究对生物多样性和影响生物多样性的因子进行评估。研究所采用的第一手自然和生物多样性的第一手数据,如海拔、土壤类型、坡度、森林覆盖率、植物物种、鸟类物种等从大围山保护区的28个样点中获得。用CurveExpert统计软件对这些数据进行数理统计分析,分析的结果显示鸟类物种的多样性与植物物种的多样性呈明显的正相关,说明生境对动物区系多样性保护的关键作用。该研究还分析了关键景观特征与生物多样性的相关性,并对如何测度生物多样性和增强保护和管理该区域的生物多样性提出了建议。本研究的结果不仅对大围山自然保护区的生物多样性保护和管理策略的制定有重要的意义,而且对中国其他自然保护区的保护和管理也有积极地作用。  相似文献   

15.
Tree species composition is a primary attribute of forest ecosystems, and is often manipulated by silvicultural practices. Forest management to diversify tree species is now being promoted to favor biodiversity. To assess the soundness of this policy we reviewed and analyzed the literature on the relationship between tree species composition and floristic diversity, including the mechanisms involved therein. Coniferous forests generally provide less diversified vascular understories than broadleaved forests. At the tree species scale, there are not enough reports to draw firm conclusions on the effect of any particular species. Mixing of deciduous and coniferous tree species generally affects understory diversity, but in almost all cases maximum diversity is observed in one of the pure stands, not in mixed stands. Understory vegetation is influenced by overstory composition and structure through modifications of resource availability (light, water and soil nutrients) and other effects, such as physical characteristics of the litter layer. Overstory light transmittance and diverse properties of forest litter are factors that have been most fully studied to date, but other factors such as throughfall water quantity and chemistry may also play a role. While the relative importance of mechanisms that account for the effect of overstory on understory biodiversity has often been discussed, these mechanisms have rarely been the subject of formal experiments. Overall, varying management practices and site attributes make it difficult to generalize results. They combine with the effects of tree species in influencing understory vegetation diversity, but they have been rarely considered. Future research is needed to gain a better understanding of the relationship between overstory and understory diversity and establish general laws.  相似文献   

16.

Context

The remaining riparian stretches are often the unique suitable habitats for forest breeding birds in Mediterranean landscapes undergoing long-term changes. Understanding the interactions between riparian zones and their surroundings is critical to establish successful management actions.

Aims

We assessed the influence of surrounding matrix on riparian bird communities and the use of riparian galleries as surrogate habitats for the forest passerine communities of southwestern Iberia.

Methods

We used point counts in three simultaneous sampling stations, one in the riparian gallery and two in the adjacent matrix. Three matrix types were selected with a decreasing tree density gradient: dense montado, sparse montado, and open agricultural areas. Data were analysed with redundancy analysis and differences in species’ occurrences were tested with one-way ANOVA.

Results

In riparian galleries, we found bird species belong to three ecological guilds: riparian, woodland, and edge guilds. The richness of bird guilds and the occurrence of some species depended on the surrounding matrix type. Riparian bird richness was constant in all surrounding matrices, woodland bird guild was richer in galleries embedded in dense montados, and edge guild in riparian galleries surrounded by sparse montados. Five among 19 assessed species were influenced by matrix type, within particular a few strictly riparian species. Species richness increased close to riparian galleries, due to the increase in habitat heterogeneity and resource availability for birds in densely vegetated riversides. However, the occurrence of some bird species differed according to the type of surrounding matrix.

Conclusion

The matrix type explained most of the variance in riparian bird assemblages. Some woodland birds have used riparian galleries as surrogate habitat. Our study suggests that land use in the surrounding matrices must be taking into account for the management and rehabilitation of watercourses and bird conservation actions.  相似文献   

17.
The extensive area of degraded tropical land and the calls to conserve forest biodiversity and sequester carbon to offset climate change demonstrate the need to restore forest in the tropics. Deforested land is sometimes replanted with fast-growing trees; however, the consequences of intensive replanting on biomass accumulation or plant and animal diversity are poorly understood. The purpose of this study was to determine how intensive replanting affected tropical forest regeneration and biomass accumulation over ten years. We studied reforested sites in Kibale National Park, Uganda, that were degraded in the 1970s and replanted with five native tree species in 1995. We identified and measured the size of planted versus naturally regenerating trees, and felled and weighed matched trees outside the park to calculate region-specific allometric equations for above-ground tree biomass. The role of shrubs and grasses in facilitating or hindering the establishment of trees was evaluated by correlating observed estimates of percent cover to tree biomass. We found 39 tree species naturally regenerating in the restored area in addition to the five originally planted species. Biomass was much higher for planted (15,675 kg/ha) than naturally regenerated trees (4560 kg/ha), but naturally regenerating tree regrowth was an important element of the landscape. The establishment of tree seedlings initially appeared to be facilitated by shrubs, primarily Acanthus pubescens and the invasive Lantana camara; however, both are expected to hinder tree recruitment in the long-term. Large and small-seeded tree species were found in the replanted area, indicating that bird and mammal dispersers contributed to natural forest restoration. These results demonstrate that intensive replanting can accelerate the natural accumulation of biomass and biodiversity and facilitate the restoration of tropical forest communities. However, the long-term financial costs and ecological benefits of planting and maintaining reforested areas need to be weighed against other potential restoration strategies.  相似文献   

18.
The integration of agroforestry plots with ephemeral crops such as vegetables on the farm scale can probably serve as a refuge and source of beneficial insects. Therefore, agroforestry systems possibly represent an alternative that favors ecosystem services and help growers in the transition process from conventional to agro-ecological agriculture. This study aimed to understand the role of introducing agroforestry systems in structuring insect communities, with consequences for the abundance of herbivore and natural enemies, contributing to farm management and favoring biological control as an ecosystem service. Field surveys showed that agroforestry systems can harbor more species than horticultural crops, independent of the functional group. They also contain a greater diversity of herbivores and an even greater diversity profile of natural enemy communities. Agroforestry systems served as a source of natural enemies that can colonize horticultural crops when herbivores are present. As a consequence, natural enemies can establish a numerical response to herbivore abundance, but their communities are also affected by stochastic factors related to climatic conditions. Thus, agroforestry systems and agro-ecological practices might favor an agriculture based on the maintenance and conservation of ecosystem services.  相似文献   

19.
The effect of forest management on biodiversity is a crucial issue for sustainable forestry and nature conservation. However, the ways in which management affects macrofungal and plant communities and diversity of mountain temperate forests still remain poorly understood. We performed a random sampling stratified by stand age and stand type on the sites of temperate montane fir–beech forests. Diversity of macrofungi and the vascular plant understorey in beech- and spruce-dominated managed stands was investigated and compared to primeval forests located in the Po?ana Biosphere Reserve, Western Carpathians. Both the vascular plant and the macrofungal communities were altered by management, and the response of the macrofungal species (especially wood-inhabiting fungi) was more pronounced in terms of species composition change. Species turnover evaluation seems to be an important tool of forest natural status assessment, because alpha diversity did not change as much as species composition. Certain species of Carpathian primeval forests were confirmed as good indicators for natural forest change; others were proposed. Species pool and mean number of species per plot were the highest in unmanaged fir–beech forests, and species diversity significantly decreased in spruce plantations. The number of species decreased significantly due to the change of canopy tree species composition only in the macrofungal communities. As an outcome for forest management, we recommend keeping mixed forests involving all natural tree species and providing at least a minimal amount of dead wood necessary for wood-inhabiting organisms and leaving some area of unmanaged natural forests within complexes of managed stands.  相似文献   

20.
Woodpeckers (family Picidae) merit specific monitoring and management efforts, both as keystone/facilitator species and as indicators of forest condition. Recent studies indicated that species richness of woodpeckers was correlated with richness of all forest birds, thus suggesting potential exists for management practices that can address needs of woodpeckers in particular and other forest birds in general. We used data from a long-term study (1995–2008) from forest sites in the interior of British Columbia to evaluate how abundances of seven woodpecker species varied with habitat variables previously identified as associated with forest bird richness. We found that tree species richness had either a neutral or positive effect on the abundance of all woodpecker species, whereas abundances of most woodpecker species tended to be lower in stands with high densities of lodgepole pine. Abundances of most woodpecker species were positively correlated with density of beetle-killed pines. Relative to control sites, higher densities of most woodpecker species were found at harvested sites where most trembling aspen and large Douglas-fir trees had been retained. Therefore, management strategies that favour a mixture of tree species, with particular attention to retention of aspen, should safeguard populations of most woodpecker species. Abundances of individual woodpecker species were weakly but positively inter-correlated before the beetle outbreak, and less so during and post-outbreak. It thus appears that no strong trade-offs exist among woodpecker species. These results, combined with previously identified positive correlations between woodpecker and forest bird richness, indicate woodpeckers can be managed as a suite for the purpose of managing avian biodiversity as a whole.  相似文献   

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