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土地利用变化是土地利用类型从低生态位向高生态位转变的自组织行为。在生态位理论基础上,运用土地利用生态位模型定量分析了石家庄市土地利用数量生态位和经济生态位。研究表明,石家庄市土地利用数量生态位中,耕地数量生态位最高,其次是草地、林地和城镇村及工矿用地,交通运输用地数量生态位最低;2000—2009年期间,耕地、草地数量生态位呈总体下降趋势,园地、林地、城镇村及工矿用地和交通运输用地数量生态位呈总体上升趋势;农用地与建设用地经济生态位差值较大,近几年市域经济发展和城市化进程加快更加剧了这种差值的进一步拉大。最后,根据不同土地利用类型的特点,从提高土地利用经济生态位的角度探讨了土地可持续利用的途径。 相似文献
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竹山县土地利用景观格局动态变化分析 总被引：1，自引：1，他引：0
《林业资源管理》2018,(6)
以湖北省竹山县1999年、2005年、2011年及2017年4期遥感影像为数据源,借助Arc GIS,ENVI和Fragstats等软件,提取研究区土地利用景观格局变化信息,采用主成分分析法,定量分析其驱动因素。结果表明:1)近18年来,研究区土地利用类型以林地、耕地和水域为主,土地利用程度综合指数呈下降趋势;2)土地转移主要以耕地和裸地转出,以林地、建筑用地和水域转入为典型特征,土地利用总体趋势与状态指数呈先下降后上升;3)景观结构上,林地一直是研究区优势景观类型,各景观类型面积占比顺序并未发生改变,斑块总数量呈下降趋势;4)景观异质性上,香农多样性指数和均匀度指数呈下降趋势,蔓延度指数呈上升趋势,说明研究区优势景观类型林地对整体景观格局控制力增加,各类景观类型空间连通性增强;5)社会经济和农业生产是研究区土地利用景观格局变化的主要驱动力。 相似文献
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文章利用RS和GIS的空间分析技术,以TM遥感影像为主要信息源,通过目视解译的方法提取研究区土地利用动态变化数据,结合现地调查进行区域土地利用动态变化分析。研究结果表明:研究区不同土地利用类型之间转换明显,其中,以耕地、草地面积减少,林地、灌木林地、居民地和工矿用地增加为主。土地利用类型变化主要受经济因素影响,国家投入增加和地方经济的发展是土地利用变换的主要原因。 相似文献
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采用1999年TM卫星影像及2006年SPOT 5卫星影像,借助已有森林资源二类调查资料对此期间勐腊县象明乡土地利用变化状况进行分析.对分析的原理、方法、步骤作了论述.分析结果表明,期间总的趋势是林地面积增加,农地面积减少;有林地面积增加、宜林荒山减少;乔木经济林增加,其它灌木林减少.分析结果符合当地同期土地利用实际状况. 相似文献
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准确地从遥感影像通过分类方法获取土地覆盖信息是一项基础性的重要课题.在建立土地覆盖分类体系的基础上,对株洲市1999年、2003年和2007年3个时相CBERS星CCD数据进行监督分类,提取土地覆盖信息,并分析其动态变化过程.结果表明:在我国中部丘陵地区,利用多时相CBERS星CCD数据开展土地覆盖变化遥感动态监测取得了较理想的效果;1999年至2007年间,株洲市林地、水体和城镇居民点面积所占比重逐渐提高,林地和城镇居民点面积增幅较大,增速呈放缓趋势,从而造成农用地和其他土地面积减少,这可为株洲市合理利用土地资源和地区可持续发展提供一定的科学依据. 相似文献
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为评估县域生态风险及演化特征,选取嘉禾县2010、2015、2020年的土地变更调查数据,基于土地利用生态风险指数构建生态风险模型,采用空间分析方法,研究了嘉禾县土地利用变化特征以及生态风险演变规律。结果表明：研究区内土地利用类型主要是林地和耕地,2010～2020年土地利用数量和结构变化明显,林地、园地、建设用地增加,耕地、草地、未利用地面积减少;2010年以来县域生态风险上升区分布广泛,多为逐级上升,主要集中在县域中部城乡发展较为活跃地区;县域生态风险下降区分布集中,下降幅度显著,分布区域主要受重大生态修复工程实施的控制。县域生态风险整体呈现出生态风险逐渐升高,且生态风险两级向中段演化的趋势。 相似文献
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基于RS与GIS的哈尔滨市土地利用格局演变及其预测研究 总被引：3，自引：0，他引：3
以哈尔滨市1989年、2007年2期Landsat TM遥感影像为主要数据源,在RS和GIS的支持下,分析土地利用格局的动态演变,并应用马尔可夫模型完成对研究区未来土地利用的定量预测。研究结果表明:林地、水域和草地发生了扩张,耕地、居民工矿用地和未利用地减少;耕地和林地具有较高的保留率,草地和未利用地具有较高的转换率;2007年以后土地利用变化的趋势是林地逐年增加,其它土地利用类型逐年减少,该变化持续到2079年后,区域土地利用达到相对稳定状态时,耕地占57.79%,林地占25.24%,草地占2.80%,水域占3.98%,居民工矿用地占9.28%,未利用土地占0.91%。 相似文献
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蕉岭长潭省级自然保护区表土有机碳的研究 总被引：3，自引：2，他引：1
基于UTM公里网格方法划分的66个网格的土壤剖面数据,分析了蕉岭长潭自然保护区5种典型植被类型（马尾松林、杉木林、针阔混交林、阔叶混交林和竹林）的表层土壤（0～20 cm）有机碳含量、密度、储量的分布特征与影响因子。结果表明：（1）表土有机碳含量SOC分布在12.61～66.19 g·kg^-1之间,平均值为30.87±1.30 g·kg^-1,大小顺序为竹林〉阔叶混交林〉针阔混交林〉杉木林〉马尾松林,多重比较显示竹林（37.63 g·kg^-1）显著高于马尾松林（18.52 g·kg^-1）,马尾松林仅为竹林的49.21%。（2）表土有机碳密度SOCD在3.27～15.69 kg·m^-2间,平均值为8.22±0.39 kg·m^-2,大小排序为阔叶混交林〉竹林〉针阔混交林〉杉木林〉马尾松林,阔叶混交林（10.15 kg·m^-2）和竹林（9.96 kg·m^-2）的SOCD值显著高于马尾松林（4.82 kg·m^-2）（p=0.005,p=0.036）,马尾松林仅是阔叶混交林的47.49%。（3）蕉岭长潭保护区表土层有机碳储量为402 100 t,占总面积54.54%的针阔混交林贡献最大,其次为阔叶混交林、杉木林、竹林和马尾松林。（4）表土有机碳含量与土壤全氮、速效钾含量显著正相关,相关系数分别为0.40和0.31;与石砾含量极显著负相关,相关系数达到-0.76。与林下植物分布有密切联系,有机碳含量〈20 g·kg^-1的指示种有6种,包括千年桐、黄毛楤木、米碎花、谷木冬青、长叶冻绿和乌韭,有机碳含量〉40 g·kg^-1的指示种有光叶海桐和土茯苓,有机碳含量在20～40 g·kg^-1间还未发现指示种。 相似文献
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Silvio Frosini de Barros Ferraz Carlos Alberto Vettorazzi David M. Theobald 《Forest Ecology and Management》2009
In Rondônia State, Brazil, settlement processes have cleared 68,000 km2 of tropical forests since the 1970s. The intensity of deforestation has differed by region depending on driving factors like roads and economic activities. Different histories of land-use activities and rates of change have resulted in mosaics of forest patches embedded in an agricultural matrix. Yet, most assessments of deforestation and its effects on vegetation, soil and water typically focus on landscape patterns of current conditions, yet historical deforestation dynamics can influence current conditions strongly. Here, we develop and describe the use of four land-use dynamic indicators to capture historical land-use changes of catchments and to measure the rate of deforestation (annual deforestation rate), forest regeneration level (secondary forest mean proportion), time since disturbance (mean time since deforestation) and deforestation profile (deforestation profile curvature). We used the proposed indices to analyze a watershed located in central Rondônia. Landsat TM and ETM+ images were used to produce historical land-use maps of the last 18 years, each even year from 1984 to 2002 for 20 catchments. We found that the land-use dynamics indicators are able to distinguish catchments with different land-use change profiles. Four categories of historical land-use were identified: old and dominant pasture cover on small properties, recent deforestation and dominance of secondary growth, old extensive pastures and large forest remnants and, recent deforestation, pasture and large forest remnants. Knowing historical deforestation processes is important to develop appropriate conservation strategies and define priorities and actions for conserving forests currently under deforestation. 相似文献
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【目的】提取浙江省不同时期竹林分布信息,分析其时空演变规律,揭示竹林面积变化与土地利用格局之间的关系,为国家及至全球尺度长时间序列的竹林时空动态研究提供参考。【方法】以浙江省为研究区,基于2000、2004和2008年Landsat5 TM及2014年Landast8 OLI时间序列影像数据,首先,对不同时期的Landsat数据进行大气校正和几何校正,采用最大似然法提取土地利用和竹林时空分布信息;然后,利用变化幅度和动态度2个指标分析4个时期、3个时间段的竹林时空演变规律;最后,建立全省土地利用时空转移矩阵,揭示竹林时空动态与土地利用格局之间的关系。【结果】1)基于时序Landsat数据提取的浙江省竹林信息精度较高,分类精度达75%以上,使用者精度达91%以上,且分类统计面积与实际清查面积高度吻合,面积提取精度达96%以上; 2) 2000—2014年浙江省竹林面积变化幅度和年均变化率分别为16.55%和1.18%,在时空上呈逐渐增加趋势; 3)浙江省竹林面积由2000年占全省面积的7.33%增长到2014年的8.56%,其中针叶林、阔叶林和农田3种土地利用类型变化对竹林面积增加的贡献最大,贡献率分别为28.62%、37.23%和16.15%。【结论】基于Landsat时间序列数据能够高精度监测浙江省竹林资源动态变化,针叶林、阔叶林和农田等土地利用类型减少对竹林面积时空演变具有显著影响。 相似文献
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浙江杭州富阳区竹类植物资源及竹产业发展建议 总被引：2，自引：0，他引：2
杭州市富阳区自然条件优越,竹资源丰富,栽培利用历史悠久,竹文化底蕴丰厚,发展竹产业有着坚实的基础。文章在分析富阳区竹资源特点、竹林经营现状及存在问题的基础上,提出了富阳区发展壮大竹产业的建议。 相似文献
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为研究富阳竹纸的耐老化性能,选取杭州富阳逸古斋元书纸有限公司生产的超级元书、二级元书、冬纸壹号及古籍修复纸这4种富阳手工竹纸进行干热加速老化试验。基于样品的D65亮度、抗张指数、断裂伸长率、表面pH及热稳定性等理化性能指标在老化过程中的变化情况,分析富阳竹纸的耐老化性能。试验结果表明:所有竹纸样品的D65亮度在老化过程中发生了不同程度的下降,其中经过纯碱二次煮料或化学漂白的竹纸,老化前后D65亮度的变化相对较小,即竹纸的D65亮度稳定性与纸浆的处理程度呈正相关。但经过多次煮料和化学漂白的竹纸,其热稳定性在老化后发生小幅度的下降,说明工艺处理程度过大会影响竹纸的热稳定性。强度方面,初始抗张指数较高的竹纸,经老化后仍保留较好的强度性能。在老化过程中,所有竹纸样品的pH均逐渐降低,其中化学漂白竹纸的下降幅度最大,即化学漂白会加速竹纸的酸化。4种富阳竹纸的耐老化性能存在差异:冬纸壹号各方面的性能在老化过程中相对比较稳定,超级元书的各项性能经老化后发生了一定程度的下降,二级元书的强度稳定性和热稳定性能较好,古籍修复纸的D65亮度稳定性最好。 相似文献
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Xiangang Chen Xiaoquan Zhang Yiping Zhang Trevor Booth Xinhua He 《Forest Ecology and Management》2009,258(7):1489-1496
Bamboo stands are one of the most important forest types in China, covering an area of about 4.99 million hectares, and estimation of their carbon stocks is vital for China's national carbon accounting. Bamboo biomass and carbon fraction, as well as soil bulk density and soil organic matter content, data were collated from 40 publications describing conditions at 35 sites in 10 Chinese provinces where most bamboo stands are distributed. Carbon stocks and its changes in the living biomass and soil organic matter in bamboo stands in China in the past five decades were estimated based on these collated data together with the area of bamboo stands and number of bamboo culms derived from the National Forestry Inventory (NFI). Our estimates indicate that the carbon stocks in bamboo stands in China have been increasing since the 1950s with estimated values of 318.55 Tg C (1950–1962), 427.37 Tg C (1977–1981), 463.80 Tg C (1984–1988), 493.00 Tg C (1989–1993), 548.79 Tg C (1994–1998) and 631.58 Tg C (1999–2003) accompanying the increase of bamboo stand area. Based on correlation between forest area and bamboo area, as well as the trends of forest area predicted in government strategy documents for forest development over the next five decades, the carbon stocks in bamboo stands for 2010, 2020, 2030, 2040 and 2050 are estimated to be 727.08 Tg C, 839.16 Tg C, 914.43 Tg C, 966.803 Tg C and 1017.64 Tg C, respectively. 相似文献
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《Journal of Sustainable Forestry》2013,32(1-2):127-141
Abstract The distribution of Phyllostachys pubescens, introduced to Japan from China in 1736, has been expanding. The expansion was studied in Tanabe Town, Kyoto Pref., Central Japan. Long term expansion was traced using a topographic map, a land-use map and aerial photographs. Within the research region (21.35 km2), the number and total area of bamboo sites increased from 24 and 0.16 km2 in 1953 to 174 and 3.04 km2 in 1985. By contrast, the total area of tree sites decreased from 12.2 km2 in 1953 to 8.5 km2 in 1985. The average area of bamboo sites also increased from 0.67 ha in 1953 to 1.75 ha in 1985. The average rates of the current expansion, measured by censusing current and old culms in the front of 10 unmanaged bamboo sites, were 2.1 m yr-1. Stand structure was detailed in a transitional area from a pure stand of P. pubescensto a mixed broadleaved forest. Stand structure was simpler in the area dominated by P. pubescens.Culms off! pubescenswere larger in the pure stand, and variations in DBH and height were smaller for the bamboo than for the trees in each sample site. P. pubescenshad a greater average crown length and higher canopy position. These traits allow P. pubescensto invade adjacent forests, form a uniform monolayer of foliage, and dominate competing vegetation. There was no evidence of seedling regeneration under the bamboo. More than two-thirds of the Japanese forest is secondary growth or young plantations of conifers, and in most of these, canopy height is lower than that of P. pubescens.The continuous area increment in bamboo from 1953 to 1985, positive current expansion rate in the front of unmanaged bamboo stands and the advantageous stand structure of bamboo suggest that the range expansion of P. pubescensin the secondary forest will continue in the future. 相似文献
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Interactions between forest canopy characteristics and plants in the forest understory are important determinants of forest community structure and dynamics. In the highlands of southwestern, China the dwarf bamboo Bashania fangiana Yi is an understory dominant beneath a mixed canopy of the evergreen Abies faxoniana (Rheder & Wilson) and the deciduous Betula utilis (D. Don). The goal of this study was to better understand the role of bamboo dominance, canopy characteristics, and periodic bamboo dieback on forest development. To achieve this goal, we measured tree seedling, tree saplings, and trees, forest canopy characteristics, and bamboo cover in permanent forest (n = 4) and gap plots (n = 31) in a mixed A. faxoniana and B. utilis forest in Sichuan, China. Dwarf bamboos died off in 1983 in the gap plots, and in three of the four forest plots. Forest development was assessed for the period 1984–1996. The seedling bank in forest and gap plots increased after bamboo die-off. A. faxoniana seedlings increased more than B. utilis in forest plots; the opposite pattern characterized gap plots. The proportion of seedlings on raised micro-sites on the forest floor also changed and new seedling were more abundant on the forest floor. By 1996, bamboo seedling cover and biomass had recovered to ca. 45% or their pre-flowering values. Rates of bamboo seedling recovery were faster beneath canopy gaps and deciduous trees than beneath forest or evergreen trees. Tree mortality exceeded recruitment in plots with dense bamboo; the opposite pattern was found in the plot with little bamboo. The mortality rate for B. utilis trees (2.4% year−1) was higher than that for A. faxoniana (0.8% year−1) and forests with dense bamboos became more open over the census period. Tree mortality was size-dependent and intermediate sized trees had the lowest rates of mortality. Stand basal area increased mainly due to greater basal area gain than loss for A. faxoniana. Interactions between tree species life history, canopy type, and bamboo life-cycles create heterogeneous conditions that influence tree and bamboo regeneration and contribute to the coexistence of A. faxoniana and B. utilis in old-growth forests in southwestern China. 相似文献