近十年,无人机平台由于其灵活机动、成本低等优势在植被生态调查、资源环境监测、生物多样性保护等领域逐渐兴起。本文从生物多样性遥感监测应用角度首先介绍了无人机分类系统,为具体工作开展过程中如何选择合适的载体和传感器提供了参考;继而总结了不同类型无人机的适用性及其可搭载传感器的用途与区别。在此基础上,针对无人机平台的高精度遥感信息具体应用案例,就反映生物多样性变化并揭示其驱动机制方面的无人机遥感直接和间接指标的相关研究进展展开阐述。最后,就目前无人机遥感技术在生物多样性监测领域的应用中存在的限制,如软硬件结合匹配程度不够、部分设备过于昂贵、法律法规不完善、与传统生物多样性监测手段结合较弱等问题进行探讨。我们认为:无人机遥感技术可以很好地弥补地面监测与航天、卫星遥感之间的尺度空缺,更好地将监测点上的结果以准确、可靠的推绎方法扩展到区域尺度供决策分析使用。今后迫切需要进一步加大生物多样性近地面遥感监测项目建设的实施力度,从整体上提高生物多样性热点区域应对变化的分析预警能力。

近十年,无人机平台由于其灵活机动、成本低等优势在植被生态调查、资源环境监测、生物多样性保护等领域逐渐兴起。本文从生物多样性遥感监测应用角度首先介绍了无人机分类系统,为具体工作开展过程中如何选择合适的载体和传感器提供了参考;继而总结了不同类型无人机的适用性及其可搭载传感器的用途与区别。在此基础上,针对无人机平台的高精度遥感信息具体应用案例,就反映生物多样性变化并揭示其驱动机制方面的无人机遥感直接和间接指标的相关研究进展展开阐述。最后,就目前无人机遥感技术在生物多样性监测领域的应用中存在的限制,如软硬件结合匹配程度不够、部分设备过于昂贵、法律法规不完善、与传统生物多样性监测手段结合较弱等问题进行探讨。我们认为:无人机遥感技术可以很好地弥补地面监测与航天、卫星遥感之间的尺度空缺,更好地将监测点上的结果以准确、可靠的推绎方法扩展到区域尺度供决策分析使用。今后迫切需要进一步加大生物多样性近地面遥感监测项目建设的实施力度,从整体上提高生物多样性热点区域应对变化的分析预警能力。

林窗是当前森林生态学的重要研究内容,也是促进森林植物多样性发展的重要推动力.笔者对林窗的涵义进行了详细的介绍,阐述了林窗的形状、大小、结构、存在期等特征,重点分析了林窗内地形、温度、湿度、光照等适宜生物多样性的环境条件,最后总结了林窗对植物多样性的影响规律.

林窗是当前森林生态学的重要研究内容,也是促进森林植物多样性发展的重要推动力.笔者对林窗的涵义进行了详细的介绍,阐述了林窗的形状、大小、结构、存在期等特征,重点分析了林窗内地形、温度、湿度、光照等适宜生物多样性的环境条件,最后总结了林窗对植物多样性的影响规律.

A time series of large-scale aerial photographs of a 25 ha section of the Jasper Ridge Biological Preserve (JRBP) in California was analysed for the quantification of long-term changes in the orthogonally projected crown areas of a sample of mature canopy trees growing in closed woodland and open grassland habitats. Crown area changes were computed on the basis of pairwise image comparisons for the years 1974, 1980, 1988, 1989, 1990, 1991, 1993 and 1995. Single frame image correction methods were assessed by comparing a high-resolution physical-system based method of photogrammetric orthorectification with a low-resolution method of georeferencing that involved the use of ground control points (GCPs) for the derivation of best-fit statistical transformations. The same crown digitization procedure was used for both methods, and a statistically significant difference was not found between the high-resolution and low-resolution measured crown areas. Crown area changes were not correlated with differences in sun position at the time of aerial photo acquisition nor with differences in the off-nadir distances of each crown in the images being compared. The upper limit of digitizing error was 3.5% based on the mean coefficient of variation plus one standard deviation computed from repeat digitization measures of each crown. Crown area changes exceeding 3.5%in the pairwise image comparisons were attributed to actual crown growth or crown reduction. Expressed as a percentage of the original crown area, the mean annual rate of change for each pairwise sample period was 4.9% yr-1. In absolute terms, the mean annual rate of crown area change over the 21-year period 1974-1995 was 1.4m2 yr-1. The long-term mean annual crown growth rate of the clustered woodland trees (1.3m2yr-1) was not significantly different from the isolated grassland trees (1.5m2 yr-1). The mean annual rates of change for the periods 1974-1980, 1980-1989 and 1991-1993 were similar to the long-term average. Unusually low mean growth rates characterized the drought years of 1989-1990 and 1990-1991, while the relatively wet period of 1993-1995 exhibited the most dramatic increase in crown area at a mean rate of 3.0m2yr-1.

Abstract Little is known about the gap pattern of primeval beech forests, since large-scale studies with continuous coverage are lacking. Analyses of forest structural patterns have benefitted from advances in remote sensing, especially with the launch of satellites providing data of submetric ground resolution. These developments can strongly advance our knowledge of natural forest dynamics and disturbance regimes. The Uholka-Shyrokyi Luh forest in the Ukrainian Carpathians, the largest remnant of primeval European beech ( Fagus sylvatica L.) covering 102.8 km2, is an outstanding object to analyze the frequency distribution of gap sizes and to infer processes of forest dynamics. A stereo pair of very high-resolution WorldView-2 satellite images was used to characterize the forest's gap pattern. Canopy gaps were first digitized stereoscopically based on the image pair. In a second step, spectral properties in the red and yellow frequency bands were used to distinguish the stereoscopically mapped gap areas from non-gap areas, which enabled gap mapping over the entire study area. To validate the spectral gap mapping 338 randomly distributed samples were assigned manually to gap and non-gap areas based on the ortho-images. We found excellent agreement except for an overestimation of gaps close to clouds due to diffuse image areas. The frequency distribution of gap size revealed the forest to be structured by a small-scale mosaic of gaps mainly 2</sup> (98% of the gaps). Only a few large, stand-replacing events were detected, most probably caused by a wind storm in March 2007 and a heavy wet snow fall in October 2009. The small canopy gaps reflect fine-scale processes shaping forest structure, i.e., the death of single trees or groups of a few trees and is in line with the findings of the terrestrial forest inventory. We conclude that remote sensing approaches based on very high-resolution satellite images are highly useful to characterize even small-scale forest disturbance regimes and to study long-term gap dynamics. Stereo satellite images provide two viewing angles of the study area, thus allowing for a highly accurate mapping of canopy gaps in forests with a complex topography.

无人机与遥感技术的结合，即无人机遥感。与传统的以卫星和有人机遥感相比，无人机遥感具有高时效、高时空分辨率、云下低空飞行、高机动性等优势，是传统卫星和有人机遥感手段所无法比拟的。这些优点使得无人机在生态学和保护生物学等领域获得迅速发展。首先对无人机遥感技术的发展历程、系统组成、分类与选型、应用优势等进行了介绍。在此基础上，对无人机在生态学中的应用案例进行了总结，内容涉及生境监测、植物物候调查、动物监测等方面。最后通过比较国内外相关领域的研究进展对无人机生态学存在的问题（技术门槛较高和法律法规不完善等）和潜在应用前景进行了探讨。

无人机与遥感技术的结合，即无人机遥感。与传统的以卫星和有人机遥感相比，无人机遥感具有高时效、高时空分辨率、云下低空飞行、高机动性等优势，是传统卫星和有人机遥感手段所无法比拟的。这些优点使得无人机在生态学和保护生物学等领域获得迅速发展。首先对无人机遥感技术的发展历程、系统组成、分类与选型、应用优势等进行了介绍。在此基础上，对无人机在生态学中的应用案例进行了总结，内容涉及生境监测、植物物候调查、动物监测等方面。最后通过比较国内外相关领域的研究进展对无人机生态学存在的问题（技术门槛较高和法律法规不完善等）和潜在应用前景进行了探讨。

林窗面积、形状及边界木高是决定林窗环境异质性的3个林窗几何特征,影响林窗内植物更新。林 窗几何特征的快速测量方法是林窗研究的基础,测量方法可分为2类：基于地面实际测量的地面法和基于林窗林冠照片的相片法。地面法费时费力,受人为因素影响 大,可测量林冠林窗和扩展林窗的面积,但不能测量林窗形状和边界木高。相片法具有简单、客观、可重复的优点,但仅适用于林冠林窗。相片法共有5种：＂平面 相片法＂、＂航片法＂、＂半球面影像法＂、＂双半球面影像法＂和＂改进的半球面影像法＂。前3种测量方法只能测量林冠林窗面积;＂改进的半球面影像法＂可 测量林冠林窗面积和形状,且精度高于前3种相片法,但所需参数最多;＂双半球面影像法＂可测量林窗面积、形状及边界木高这3个林窗几何特征,且精度较高, 但拍摄要求较高。

林窗面积、形状及边界木高是决定林窗环境异质性的3个林窗几何特征,影响林窗内植物更新。林 窗几何特征的快速测量方法是林窗研究的基础,测量方法可分为2类：基于地面实际测量的地面法和基于林窗林冠照片的相片法。地面法费时费力,受人为因素影响 大,可测量林冠林窗和扩展林窗的面积,但不能测量林窗形状和边界木高。相片法具有简单、客观、可重复的优点,但仅适用于林冠林窗。相片法共有5种：＂平面 相片法＂、＂航片法＂、＂半球面影像法＂、＂双半球面影像法＂和＂改进的半球面影像法＂。前3种测量方法只能测量林冠林窗面积;＂改进的半球面影像法＂可 测量林冠林窗面积和形状,且精度高于前3种相片法,但所需参数最多;＂双半球面影像法＂可测量林窗面积、形状及边界木高这3个林窗几何特征,且精度较高, 但拍摄要求较高。

以广东的4个自然保护区和2个生态功能区的5种林龄的林分为研究对象，用样地调查法、生物量实测方法结合植物冠层分析仪对各样方的总生物量、乔木层的生物量、多样性指数和叶面积指数进行测定，分析其分布特征及相关关系。结果表明：总生物量为乔木层〉灌木层〉草木层，其中乔木层成熟林的生物量显著高于其他龄组，生物量关系为成熟林〉近熟林〉中龄林〉过熟林〉幼龄林，呈单峰型变化，在成熟林阶段达到峰值。乔木层LAI值在O．77～4．19；乔木层随着林龄的变化，LAI差异依次为中龄林〉成熟林〉近熟林〉过熟林〉幼龄林。呈倒“U”型变化；乔木层IAI与乔木层生物量存在正相关关系。相关显著；中龄林的乔木层LAI显著高于幼龄林和过熟林．中龄林、近熟林和成熟林的乔木层LAI差异不明显。不同林龄乔木层Shannon—Winner指数为近熟林〉中龄林〉过熟林〉成熟林〉幼龄林，总体趋势呈“S”型变化；不同林龄乔木层Pielou均匀度指数为成熟林〉近熟林〉中龄林〉过熟林〉幼龄林，总体趋势呈单峰型变化。峰值在成熟林阶段：乔木层Shannon．Winner指数、乔木层Pielou均匀度指数均与乔木层生物量呈线性显著正相关。因此，不同林龄下乔木层生物量、乔木层物种多样性指数和乔木层叶面积指数均存在差异：乔木层多样性指数与乔木层生物量存在正相关关系；乔木层叶面积指数与乔木层生物量存在正相关关系。

以广东的4个自然保护区和2个生态功能区的5种林龄的林分为研究对象，用样地调查法、生物量实测方法结合植物冠层分析仪对各样方的总生物量、乔木层的生物量、多样性指数和叶面积指数进行测定，分析其分布特征及相关关系。结果表明：总生物量为乔木层〉灌木层〉草木层，其中乔木层成熟林的生物量显著高于其他龄组，生物量关系为成熟林〉近熟林〉中龄林〉过熟林〉幼龄林，呈单峰型变化，在成熟林阶段达到峰值。乔木层LAI值在O．77～4．19；乔木层随着林龄的变化，LAI差异依次为中龄林〉成熟林〉近熟林〉过熟林〉幼龄林。呈倒“U”型变化；乔木层IAI与乔木层生物量存在正相关关系。相关显著；中龄林的乔木层LAI显著高于幼龄林和过熟林．中龄林、近熟林和成熟林的乔木层LAI差异不明显。不同林龄乔木层Shannon—Winner指数为近熟林〉中龄林〉过熟林〉成熟林〉幼龄林，总体趋势呈“S”型变化；不同林龄乔木层Pielou均匀度指数为成熟林〉近熟林〉中龄林〉过熟林〉幼龄林，总体趋势呈单峰型变化。峰值在成熟林阶段：乔木层Shannon．Winner指数、乔木层Pielou均匀度指数均与乔木层生物量呈线性显著正相关。因此，不同林龄下乔木层生物量、乔木层物种多样性指数和乔木层叶面积指数均存在差异：乔木层多样性指数与乔木层生物量存在正相关关系；乔木层叶面积指数与乔木层生物量存在正相关关系。

Reduced impact logging (RIL) has been promoted as a cornerstone in sustainable forest management in the tropics, although the ecological implications of RIL guidelines are poorly understood. This study aims to identify the impact of RIL on the regeneration of commercial timber species by comparing the regeneration dynamics of logging gaps with naturally occuring canopy gaps. In the concession of Consorcio Forestal Amazonico in the region of Ucayali in the Peruvian Amazon, a total of 210 circular sample plots were established in 35 gaps in unmanaged natural forest and 35 canopy gaps in forest managed according to RIL guidelines. The size of each canopy gap was estimated by establishing a polygon that followed the vertical projection of the edge of the gap. Three circular plots of 100 m2 were established within each canopy gap. The center points of the plots were placed at the stump, mid-trunk and crown of the fallen tree. It appeared that the total abundance of seedlings did not differ significantly between logging gaps and natural canopy gaps. Instead the response to logging varied between species groups. The Clarisia sp. species group had a significant negative response to logging, while Ormosia sp., Aniba sp., Ocotea sp., Qualea sp. and Terminalia sp. were significantly more abundant in gaps of logged-over forest. A direct effect of seed tree retention on seedling abundance could not be detected statistically. Possible reasons for observed differences between untouched and logged forest and consequences of observed patterns for long-term forest development and management were discussed. It was concluded that issuing and enforcing strict guidelines on sustainable forest management is no guarantee for preserving species composition in tropical forests.

The primary and secondary subtropical evergreen broad-leaved forests at an altitude of 1720 1750m in Mt. Wawushan National Forest Park, southwestern China investigated to analyze their canopy gap formation characteristics.The sampling method and canopy formation causes were also discussed.In secondary evergreen broad-leaved fore- st,the gap density was surprisingly only 9 per hm and the size of all gaps was,no more than 10m. Almost every gap had only one gap maker,and the gap makers often died standing by suppression. Accordingly successful natural regeneration is difficult in small gap,due to the rapidly lateral growth of canopy trees. In primary evergreen broad-leaved forest, the gap density was 15 per hm, and 56% of the gaps had an area of no more than 40m. The largest gap had an area of 256m. The canopy gap accounted for 11.1% and expended gap occupied 19 8% of land area in the forest. Median area of canopy gaps and expended gaps was 59 and 105m, respectively. Most gaps had more than one gap maker,and gap makers died falling and were often from mortality events separated in time. Most gaps aged over 10yr and a few were formed recently and the estimated gap formation rate was 0 01 per year. According to falling direction of trees and the relations with growth process, slope aspect and wind, we deduced gap-maker death resulted from integrated influence among topography,climate particular in wind, tree growth characteristics, and interactions of population under competition. Adapting method of plot sampling and projection drawing used in the paper can improve investigation accuracy and help improving comparison of results in different investigation area.

Abstract The distribution of canopy gaps has been studied intensively in primeval forest, but their role as keystone structure for biodiversity under natural conditions is still poorly understood. We investigated the effect of habitat properties on saproxylic beetles in the centre, at the edge of gaps and in closed stands in one of the last and largest primeval beech forest of Europe (Uholka-Shyrokyi Luh forest, Ukraine). The abundance of saproxylic beetles was significantly higher in canopy gaps compared to the closed forest. The number of species did not differ significantly between gap centres and closed forest, but was higher in gap centres than at gap edges. Species composition in gap centres was clearly distinct from that in closed forests. The effects of biotic resources, such as the amount of dead wood or the density of big trees (DBH>70 cm), on diversity measures were weak, which might be caused by the abundance of these resources under natural conditions. Since our study site is embedded in a landscape dominated by primeval forest, the effects of habitat properties on saproxylic beetle fauna might differ from that in managed forests of Central Europe. Nevertheless, species assemblages in primeval beech forests play an important role as a reference for conservation efforts in managed beech forests of Europe.

The patterns and processes of canopy tree death and replacement were studied in the elfin forest of Monteverde, Costa Rica. Natural treefalls and limbfalls in a 5.2-ha study area opened 0.8, 1.4, and 1.0% of the area in three consecutive years with about four gaps@?ha^-^1@?yr^-^1 larger than 4 m^2. Forty-one percent of the gaps were formed by uprooted trees, 39% by snapped trees, and the remainder of limbfall, the collapse of epiphyte masses, and dead standing trees killed by lightning. Gaps were found to be spatially aggregated, with more gaps occurring within 17-20 m of one another than expected by chance. Variation among gaps was complex; the first principal component of the variation in eight important gap characteristics among 88 gaps contrasted measures of gap size with the way the gapmaker broke and the position of the gap on the slope, but accounted for only 56% of the total variation. In gaps <8 mo old, the leaf area index was 1.6, and only 8% of the area was not covered by living plants. Leaf area index increased logarithmically with time since gap formation and with gap area; 50% of the mature-forest leaf area index of 5.1 was recovered in 3 yr in gaps of 10 m^2 and in 1.5 yr in gaps of 40 m^2. Saplings of both shade-tolerant and shade-intolerant canopy tree species were more abundant in gaps than in the understory of mature forest. Sapling density increased with time since gap formation, but, given the effect of time, shade-tolerant sapling density decreased with gap area, while shade-intolerant sapling density increased. Saplings of eight species were concentrated on nurse logs, while those of one other species were concentrated on the mineral soil disturbed by uprooting trees. Experimental investigation of colonization of exposed soil in treefall gaps indicated that buried seeds give rise to many more tree seedlings that seeds dispersed into recent gaps. Many of the saplings in gaps, however, started life as epiphytic seedlings in the crowns of the trees that fell. The dynamics of this lower montane rain forest resemble many lowland forests in regards to the importance of gap-phase regeneration but differ in the sources of canopy gap colonists and in the importance of different substrates for seedling establishment.

The primary and secondary subtropical evergreen broad-leaved forests at an altitude of 1720 1750m in Mt. Wawushan National Forest Park, southwestern China investigated to analyze their canopy gap formation characteristics.The sampling method and canopy formation causes were also discussed.In secondary evergreen broad-leaved fore- st,the gap density was surprisingly only 9 per hm and the size of all gaps was,no more than 10m. Almost every gap had only one gap maker,and the gap makers often died standing by suppression. Accordingly successful natural regeneration is difficult in small gap,due to the rapidly lateral growth of canopy trees. In primary evergreen broad-leaved forest, the gap density was 15 per hm, and 56% of the gaps had an area of no more than 40m. The largest gap had an area of 256m. The canopy gap accounted for 11.1% and expended gap occupied 19 8% of land area in the forest. Median area of canopy gaps and expended gaps was 59 and 105m, respectively. Most gaps had more than one gap maker,and gap makers died falling and were often from mortality events separated in time. Most gaps aged over 10yr and a few were formed recently and the estimated gap formation rate was 0 01 per year. According to falling direction of trees and the relations with growth process, slope aspect and wind, we deduced gap-maker death resulted from integrated influence among topography,climate particular in wind, tree growth characteristics, and interactions of population under competition. Adapting method of plot sampling and projection drawing used in the paper can improve investigation accuracy and help improving comparison of results in different investigation area.

【目的】揭示西双版纳地区热带季雨林内木质藤本多样性特征,阐明木质藤本对热带季雨林共存树木的攀援方式,为研究木质藤本对热带森林更新、动态和碳固定等生态过程的影响奠定基础。【方法】参考巴拿马热带季雨林木质藤本普查规范,调查并鉴定西双版纳热带季雨林20 hm~2动态监测大样地中500块20 m×20 m样地中胸径≥1 cm的木质藤本,分析其空间分布、多样性、丰富度、径级、攀援方式及其对共生树木的攀援状况。【结果】20 hm~2大样地中胸径≥1 cm的木质藤本共有21 781株(包括分株),密度为1 089.1株·hm~(-2),其中20 611株鉴定到种,分属127种45个科;样地中木质藤本的优势科为豆科和葡萄科,分别占木质藤本物种总数的51.1%和24.4%;夹竹桃科的长节珠个体最多(2 382株),占木质藤本总株数的10.9%,其次为梧桐科的全缘刺果藤和番荔枝科的黑风藤,分别占木质藤本个体总数的10.3%和4.6%;重要值排名前三的木质藤本分别为全缘刺果藤、长节珠和阔叶风车子;样地中共有43个稀有种(密度≤1株·hm~(-2)),占总种数的33.6%,但个体数仅占个体总数的1.4%;小径级木质藤本在样地中比例较高,胸径1~5 cm的个体数占总个体数的86.6%,胸径≥10 cm的仅占总个体数的0.7%;茎缠绕是主要攀援方式,所占比例达58.0%,其次是钩刺攀援和卷须缠绕,分别占16.0%和15.0%;依靠叶卷须、花梗进行攀援或蔓生的木质藤本比例较小,各占1.0%;约10.7%的树木个体(胸径≥1 cm)被木质藤本攀援,被攀援树木种数占总树种数的68.2%;随着树木个体增大,其上攀援的木质藤本数量逐渐降低,但树木被木质藤本攀援的比例增加。【结论】西双版纳热带季雨林内木质藤本种类丰富,样地中出现豆科木质藤本葛藤等先锋木质藤本表明该热带季雨林历史上可能遭受较严重干扰,加之该地区降雨季节性比较明显,使得西双版纳热带季雨林维持了较高的木质藤本多样性。

【目的】揭示西双版纳地区热带季雨林内木质藤本多样性特征,阐明木质藤本对热带季雨林共存树木的攀援方式,为研究木质藤本对热带森林更新、动态和碳固定等生态过程的影响奠定基础。【方法】参考巴拿马热带季雨林木质藤本普查规范,调查并鉴定西双版纳热带季雨林20 hm~2动态监测大样地中500块20 m×20 m样地中胸径≥1 cm的木质藤本,分析其空间分布、多样性、丰富度、径级、攀援方式及其对共生树木的攀援状况。【结果】20 hm~2大样地中胸径≥1 cm的木质藤本共有21 781株(包括分株),密度为1 089.1株·hm~(-2),其中20 611株鉴定到种,分属127种45个科;样地中木质藤本的优势科为豆科和葡萄科,分别占木质藤本物种总数的51.1%和24.4%;夹竹桃科的长节珠个体最多(2 382株),占木质藤本总株数的10.9%,其次为梧桐科的全缘刺果藤和番荔枝科的黑风藤,分别占木质藤本个体总数的10.3%和4.6%;重要值排名前三的木质藤本分别为全缘刺果藤、长节珠和阔叶风车子;样地中共有43个稀有种(密度≤1株·hm~(-2)),占总种数的33.6%,但个体数仅占个体总数的1.4%;小径级木质藤本在样地中比例较高,胸径1~5 cm的个体数占总个体数的86.6%,胸径≥10 cm的仅占总个体数的0.7%;茎缠绕是主要攀援方式,所占比例达58.0%,其次是钩刺攀援和卷须缠绕,分别占16.0%和15.0%;依靠叶卷须、花梗进行攀援或蔓生的木质藤本比例较小,各占1.0%;约10.7%的树木个体(胸径≥1 cm)被木质藤本攀援,被攀援树木种数占总树种数的68.2%;随着树木个体增大,其上攀援的木质藤本数量逐渐降低,但树木被木质藤本攀援的比例增加。【结论】西双版纳热带季雨林内木质藤本种类丰富,样地中出现豆科木质藤本葛藤等先锋木质藤本表明该热带季雨林历史上可能遭受较严重干扰,加之该地区降雨季节性比较明显,使得西双版纳热带季雨林维持了较高的木质藤本多样性。

通过典型抽样法,分析了川西亚高山针叶林不同大小林窗中植物物种的更新组成及其沿海拔的动态变化,研究了林窗大小及林窗海拔对林窗内植物多样性的影响。结果表明：（1）随林窗海拔的降低,乔灌层主要植物种垂直分布格局明显,林窗中植物种类组成逐渐增多,各物种更新数量逐渐增大,林窗越大,增加趋势越明显;（2）在不同海拔、不同大小林窗中,岷江冷杉Abies faxoniana在乔木层物种重要值排序中始终位列第一,大叶金顶杜鹃Rhododendron faberisp、无柄杜鹃Rhododendron watsonii和华西箭竹Fargesia nitida重要值分别占据高、中、低海拔林窗中灌木层物种的首要位置,草本层主要物种排序有变化,但无明显规律;（3）物种丰富度指数、Shannon-wiener物种多样性指数与林窗大小成极显著正相关,Simpson生态优势度与林窗大小呈极显著负相关,Pielou均匀度指数与林窗大小呈正相关但相关性不显著;（4）低海拔林窗中植物多样性最高,其次为中海拔,高海拔林窗中的植物丰富度指数、Shannon-wiener物种多样性指数、Pielou均匀度指数和Simpson生态优势度指数与中低海拔之间存在显著差异。

通过典型抽样法,分析了川西亚高山针叶林不同大小林窗中植物物种的更新组成及其沿海拔的动态变化,研究了林窗大小及林窗海拔对林窗内植物多样性的影响。结果表明：（1）随林窗海拔的降低,乔灌层主要植物种垂直分布格局明显,林窗中植物种类组成逐渐增多,各物种更新数量逐渐增大,林窗越大,增加趋势越明显;（2）在不同海拔、不同大小林窗中,岷江冷杉Abies faxoniana在乔木层物种重要值排序中始终位列第一,大叶金顶杜鹃Rhododendron faberisp、无柄杜鹃Rhododendron watsonii和华西箭竹Fargesia nitida重要值分别占据高、中、低海拔林窗中灌木层物种的首要位置,草本层主要物种排序有变化,但无明显规律;（3）物种丰富度指数、Shannon-wiener物种多样性指数与林窗大小成极显著正相关,Simpson生态优势度与林窗大小呈极显著负相关,Pielou均匀度指数与林窗大小呈正相关但相关性不显著;（4）低海拔林窗中植物多样性最高,其次为中海拔,高海拔林窗中的植物丰富度指数、Shannon-wiener物种多样性指数、Pielou均匀度指数和Simpson生态优势度指数与中低海拔之间存在显著差异。

In landscape ecology,it is very important to understand and grasp the ecological principles of landscape transformation.One of the research methods in common use is to describe landscape pattern and its transformation,and then connect landscape pattern with process by means of landscape indices.Based on the previous studies on landscape indices,some researches on the landscape indices' classification,descriptive ability,relationship among indices and indices' creation were conducted in this paper.Moreover,the general principles of applying landscape indices from two different levels,namely,from single index level and from index system level,were put forward.

In landscape ecology,it is very important to understand and grasp the ecological principles of landscape transformation.One of the research methods in common use is to describe landscape pattern and its transformation,and then connect landscape pattern with process by means of landscape indices.Based on the previous studies on landscape indices,some researches on the landscape indices' classification,descriptive ability,relationship among indices and indices' creation were conducted in this paper.Moreover,the general principles of applying landscape indices from two different levels,namely,from single index level and from index system level,were put forward.

My thesis focuses on characterizing patterns of gap disturbance across a forest landscape at Barro Colorado Island (BCI), Panama, and its impact on species distribution.

Foresters have traditionally managed forests with silvicultural systems that prescribe stand homogeneity for optimized tree growth. The primacy of timber as the dominant objective is giving way to broader objectives such as sustaining the function and dynamics of ecosystems, maintaining ecosystem diversity and resilience or protecting sensitive species, while providing for a variety of ecosystem services of value to humanity. Protection and production of more diverse forest values demands consideration of the fine-scale variability found within forest stands and an understanding of the spatial and temporal response of forest ecosystems to manipulation. Studies of gap dynamics have contributed significantly to our understanding of the role of small-scale disturbance in forest ecosystems, but have been used little by foresters for predicting ecosystem response to partial cutting. We review the gap dynamics literature paying special attention to papers that use gap size or position as predictive variables for responses indicative of silvicultural success or maintenance of ecosystem function. Like canopy gaps created by natural tree death or windthrow, gaps are also generated by silvicultural systems which remove dominant trees. Results from the Date Creek silvicultural systems study in northwestern British Columbia presented here demonstrate the utility of a gap-based approach for understanding ecosystem responses to tree cutting. We propose a gap-based approach for study response to silvicultural manipulation that: (1) aids development of cutting prescriptions that maintain functional mature or old-growth conditions; (2) refines and extends our understanding of how biological structures, organisms and ecosystem processes are affected by fine-scale variation within stands; and (3) leads to development of novel silvicultural systems that meet timber production objectives, without compromising ecosystem management principles.

为定量研究阔叶林群落的辐射消 减效应,以银瓶山自然保护区常绿阔叶林为研究对象,设置2hm2固定样地开展群落调查,并采用半球面影像技术获取冠层结构和林下光照指标,分析冠层结构对 太阳辐射的消减作用。研究表明:样地林下光照(直射光、散射光和总光照)与林冠结构(叶面积指数、林冠开度)相关性极显著;林下直射光对林下总光照的贡献 大于散射光,林冠结构与散射光的相关关系较直射光强;林冠结构与林木胸径有显著的相关性,而与林分密度的相关关系不显著;林冠对总光照的消减作用极显著, 月际变化呈单峰分布,6月份消减量最大。

Intuitively, termites would seem to be a very suitable group to illustrate effects of ecosystem fragmentation. Being detritivores, they do not control directly the rate at which their resources are available, nor do they restrict the ability of the resources to regenerate. Consequently, termites do not mask the ecosystem depletion caused by fragmentation. With this in mind, we compared the communities of termites in undisturbed Amazonian forest with those of two isolated fragments nearby, aiming to show that the differences observed may have resulted from habitat fragmentation. Dissimilarities between communities in the undisturbed forest suggest natural patchiness in their distribution, which could lead to misinterpretation of the effects of fragmentation. Continuous forest had higher species richness and fewer rare species than the fragments. Guild structure in the forest was biased towards soil-feeding termites, which are subterranean and soft bodied, and therefore more sensitive to variation in microclimate. In the fragments, litter-feeders and species intermediate between soil-feeding and wood-feeding types were numerically more important. Habitats in the forest were more equally used than in the fragments, suggesting habitat unsuitability increased with fragmentation. It is suggested that the community composition of the fragments is a result of the intrinsic patchiness of the original forest and deterministic and stochastic extinctions caused by fragmentation. The need for manipulative experiments to test such ideas is discussed.

为定量研究阔叶林群落的辐射消 减效应,以银瓶山自然保护区常绿阔叶林为研究对象,设置2hm2固定样地开展群落调查,并采用半球面影像技术获取冠层结构和林下光照指标,分析冠层结构对 太阳辐射的消减作用。研究表明:样地林下光照(直射光、散射光和总光照)与林冠结构(叶面积指数、林冠开度)相关性极显著;林下直射光对林下总光照的贡献 大于散射光,林冠结构与散射光的相关关系较直射光强;林冠结构与林木胸径有显著的相关性,而与林分密度的相关关系不显著;林冠对总光照的消减作用极显著, 月际变化呈单峰分布,6月份消减量最大。

Canopy gaps play a significant role in maintaining structure and composition of tropical forests. This study was carried out in tropical evergreen forests of central Western Ghats in India to understand the influence of canopy gap size and the relationship of gap regime attributes to diversity measures and regeneration. The average gap size in the study area was found to be 396 m2 and around half of gaps were 4 8 years old. Gaps created by natural single tree fall were smaller in size but significantly higher in number. Diversity and regeneration of woody species were compared with canopy gaps and intact vegetation. Species richness and diversity was higher in gaps than in intact vegetation. Macaranga peltata, a shade intolerant species dominated gaps while intact vegetation was dominated by shade tolerant Kingiodendron pinnatum.Gap size significantly influenced species diversity and regeneration. Gap area and age were significantly and negatively correlated with diversity measures but positively correlated with regeneration. Among all the attributes of gaps, regeneration was significantly positively correlated with light intensity. Gaps maintained species diversity and favored regeneration of woody species. In addition to gap size and age, other gap ecological attributes also affected species diversity and regeneration.

The abundance and diversity of lianas were examined along a tropical forest chronosequence at the Barro Colorado Nature Monument, Panama. Lianas 0.5 cm diameter were sampled along transects in two replicated stands in secondary (20, 40, 70 and 100 y after abandonment) and old-growth (> 500 y) forests. Ordination of stands based on relative abundance, but not presence-absence, showed a significant separation of stands by age. Lianas were significantly more abundant and diverse (Fisher's ) in younger forests (20 and 40 y) than in older forests (70 and 100 y, and old-growth). The decline in liana abundance with stand age was offset by increased mean basal area per individual, resulting in a relatively constant total basal area and estimated biomass across stand age. The proportions of tendril climbers decreased and stem twiners increased over stand age. Decline in liana abundance and changes in liana composition may be related to changes in support and light availability. Although lianas are recognized as playing an important role in the early secondary succession of many tropical forests, these results have shown that their important contribution to total basal area and biomass can continue as the forest matures, even as the number of established lianas declines.

对西双版纳勐养自然保护区植被的类型进行了划分,包括人工和自然群落,共有7个大类、15个群系、24个群落类型分布.对每个类型的主要组成种类、生态特征和分布现状进行了初步研究.利用地理信息系统软件制取植被图并获得了各种植被类型的分布面积和分布格局特征,这一地区亚热带季风常绿阔叶林的分布面积和所占比例最大,达总面积的41.26%;而热带雨林面积不超过总面积的10%.依据地形、海拔、气候和现状植被分布的规律,在获得景观类型图的基础上,得到了可以反映这一地区在完全自然条件下植被可能分布的状况的还原植被图,为保护区的发展和植被的恢复提供了理论依据。

对西双版纳勐养自然保护区植被的类型进行了划分,包括人工和自然群落,共有7个大类、15个群系、24个群落类型分布.对每个类型的主要组成种类、生态特征和分布现状进行了初步研究.利用地理信息系统软件制取植被图并获得了各种植被类型的分布面积和分布格局特征,这一地区亚热带季风常绿阔叶林的分布面积和所占比例最大,达总面积的41.26%;而热带雨林面积不超过总面积的10%.依据地形、海拔、气候和现状植被分布的规律,在获得景观类型图的基础上,得到了可以反映这一地区在完全自然条件下植被可能分布的状况的还原植被图,为保护区的发展和植被的恢复提供了理论依据。

2008年1—2月,雨雪冰冻天气袭击广东粤北地区,造成大面积的杉木(Cunninghamia lanceolata)林被破坏。探讨粤北地区冰雪灾害后杉木人工林冠层结构与林下光照及土壤生化特性的关系,对杉木林的恢复具有重要的实际意义。采用实地调查、半球面影像技术和稀释平板法等方法,研究恢复期间杉木林内不同林隙的冠层结构与林下光照、林下土壤微生物多样性和酶活性的关系,旨在为杉木林的恢复提供科学依据。结果表明,随着林隙面积的增大,林冠开度从10.93%增加到18.36%,叶面积指数从2.70减少到1.88,直射光从3.21mol·m~(-2)·d~(-1)增加到9.29mol·m~(-2)·d~(-1),散射光从3.02mol·m~(-2)·d~(-1)增加到5.41mol·m~(-2)·d~(-1),总光照从6.23mol·m~(-2)·d~(-1)增加到14.70mol·m~(-2)·d~(-1)。林冠开度与所在林隙范围、直射光、散射光和总光照均呈极显著正相关(P<0.01),与叶面积指数存在显著负相关(P<0.05)。叶面积指数与直射光、散射光和总光照均呈显著负相关(P<0.05)。各样方的细菌、真菌和放线菌数量分别为0.67~8.07×106、2.83~16.33×105和6.07~48.33×105CFU·g~(-1),脲酶、磷酸酶和过氧化氢酶活性分别为.34~1.88mg·kg~(-1)、196.20~418.03mg·kg~(-1)和1.00~2.00 mg·L~(-1)。林冠开度与磷酸酶及过氧化氢酶活性之间呈显著二项式关系。综上可见,冠层结构与林下光照及土壤酶活性的关系密切,一定范围内,较大的林冠开度的有利于受灾杉木人工林林下光照条件的改善和土壤酶活性的提高,但当林冠开度超过一定范围时,土壤酶活性下降。因此,冠层结构在一定程度上能决定林内光分布和反映土壤环境质量,进而影响林木整体的光合性能和林木恢复的速度。

2008年1—2月,雨雪冰冻天气袭击广东粤北地区,造成大面积的杉木(Cunninghamia lanceolata)林被破坏。探讨粤北地区冰雪灾害后杉木人工林冠层结构与林下光照及土壤生化特性的关系,对杉木林的恢复具有重要的实际意义。采用实地调查、半球面影像技术和稀释平板法等方法,研究恢复期间杉木林内不同林隙的冠层结构与林下光照、林下土壤微生物多样性和酶活性的关系,旨在为杉木林的恢复提供科学依据。结果表明,随着林隙面积的增大,林冠开度从10.93%增加到18.36%,叶面积指数从2.70减少到1.88,直射光从3.21mol·m~(-2)·d~(-1)增加到9.29mol·m~(-2)·d~(-1),散射光从3.02mol·m~(-2)·d~(-1)增加到5.41mol·m~(-2)·d~(-1),总光照从6.23mol·m~(-2)·d~(-1)增加到14.70mol·m~(-2)·d~(-1)。林冠开度与所在林隙范围、直射光、散射光和总光照均呈极显著正相关(P<0.01),与叶面积指数存在显著负相关(P<0.05)。叶面积指数与直射光、散射光和总光照均呈显著负相关(P<0.05)。各样方的细菌、真菌和放线菌数量分别为0.67~8.07×106、2.83~16.33×105和6.07~48.33×105CFU·g~(-1),脲酶、磷酸酶和过氧化氢酶活性分别为.34~1.88mg·kg~(-1)、196.20~418.03mg·kg~(-1)和1.00~2.00 mg·L~(-1)。林冠开度与磷酸酶及过氧化氢酶活性之间呈显著二项式关系。综上可见,冠层结构与林下光照及土壤酶活性的关系密切,一定范围内,较大的林冠开度的有利于受灾杉木人工林林下光照条件的改善和土壤酶活性的提高,但当林冠开度超过一定范围时,土壤酶活性下降。因此,冠层结构在一定程度上能决定林内光分布和反映土壤环境质量,进而影响林木整体的光合性能和林木恢复的速度。

Canopy gaps play a crucial role for forest dynamics processes, as they largely determine light transmission to lower canopy strata, thereby controlling the turnover of tree individuals in the stand. Even though their functional importance is undisputed, quantitative data on the rate of gap creation and gap closure, and the temporal change in gap size distribution patterns in temperate virgin forests are scarce. We used a repeated inventory (line-intercept sampling) of gap size frequency and fraction in a virgin beech ( Fagus sylvatica ) forest in the Slovakian Carpathians over a 10-year interval (2003–2013) to test the hypotheses that (i) disturbance intensity and thus gap creation and gap closure rate change only little over time, (ii) gaps persist or even expand, until they are filled primarily by vertical ingrowth of trees from lower strata, and (iii) gap creation promotes the height growth of released saplings and sub-canopy trees. In the 2003 and 2013 inventories, 37 and 30 gaps >2062m 2 size were mapped along a total of 321762m transect line investigated. The large majority of gaps was 50062m 2 were very rare. Gap fraction decreased significantly from 13.6% in 2003 to 8.2% in 2013 (associated with a reduction in mean gap size from 261 to 9662m 2 ), indicating considerable variation in disturbance intensity in the past decades. Before 2003, both large gaps (probably caused by wind throw) and small gaps (from dying trees) have been formed, while only small gaps developed in the period 2003–2013. Small gaps were closed within a few years through rapid horizontal canopy expansion of neighboring beech trees, while vertical gap filling through ingrowth of lower canopy layers and regeneration was the dominant process in larger gaps. Saplings and trees in lower canopy layers formed a heterogeneous understory in large parts of recently formed gaps and responded to this process with increased height growth. We conclude that, despite considerable variation in disturbance intensity over time, this beech virgin forest responds to gap formation with high resilience through rapid lateral canopy expansion in small gaps and ingrowth of saplings and sub-dominant tree layers in larger gaps.

http://www.jstor.org/stable/3783843

The death of overstory trees creates gaps in forest canopies. These canopy gaps have positive impacts on forests, including enhancing species diversity. The relative contributions to canopy gap closure made by understory trees within gaps and overstory trees at gap edges determines the future structure and species composition of a forest. Most studies of tree growth responses to gaps have focused on understory trees or canopy expansion by overstory trees. Here we focus on the stem radial growth rates of overstory trees and forest growth rates, measured as stand basal area increment. Our study area was a mature mixed-age, mixed-species deciduous forest in south-central Pennsylvania, USA. A hierarchical regression analysis found that gap-edge trees ≥20 cm dbh (diameter at breast height, 1.3 m) had 26% higher stem radial growth rates than comparable trees not located at gap edges ( P=0.004). Our hypothesis that smaller overstory trees would experience a greater growth benefit at gap edges was marginally supported ( P=0.06). A tree’s position north or south of a gap did not influence its growth response to the gap. The results suggest that overstory trees make an important contribution to canopy gap closure. Canopy gaps reduced the area occupied by overstory trees by 16%. But based on our regression model of stem radial growth rates, nearly two-thirds of the stand basal area increment lost because of gaps was offset by the enhanced growth of trees at gap edges (considering trees ≥20 cm dbh only). A simple, spatially-explicit process model of tree and forest growth in relation to gaps supported this finding. These results demonstrate that the benefits of canopy gaps come at a cost in forest growth rates that is considerably less than the gap area indicates.

综述了森林凋落物研究的进展 ,森林凋落物动态的研究随研究方法的改进而不断深化。制约凋落物分解速率的因素有内在因素即凋落物自身的化学物理性质和外在因素即凋落物分解过程发生的外部环境条件 ,如参与分解的异养微生物和土壤动物群落的种类、数量、活性 (生物类因素 )和气候、土壤、大气成分等 (非生物类因素 )。讨论了全球变暖可能引起的凋落物量和凋落物分解的变化。气温上升可能引发植被分布、物候特征和制约凋落物分解因素的改变 ,影响森林凋落物动态 ,最终影响森林生态系统物质循环的功能。

1. Structural diversity and niche differences within habitats are important for stabilizing species coexistence. However, land-use change leading to environmental homogenization is a major cause for the dramatic decline of biodiversity under global change. The difficulty in assessing large-scale biodiversity losses urgently requires new technological advances to evaluate land-use impact on diversity timely and efficiently across space.2. While cost-effective aerial images have been suggested for potential biodiversity assessments in forests, correlation of canopy object variables such as gaps with plant or animal diversity has so far not been demonstrated using these images.3. Here, we show that aerial images of canopy gaps can be used to assess floristic biodiversity of the forest understorey. This approach is made possible because we employed cutting-edge unmanned aerial vehicles and very high-resolution images (7 cm pixel 1) of the canopy properties. We demonstrate that detailed, spatially implicit information on gap shape metrics is sufficient to reveal strong dependency between disturbance patterns and plant diversity (R2 up to 0 74). This is feasible because opposing disturbance patterns such as aggregated and dispersed tree retention directly correspond to different functional and dispersal traits of species and ultimately to different species diversities.4. Our findings can be used as a coarse-filter approach to conservation in forests wherever light strongly limits regeneration and biodiversity.

林窗是森林生态系统中的一种中小尺度干扰,是促进森林更新、养分循环、功能提高的重要推动力。本文阐述林窗生态学的研究进展与展望,以期为今后的林窗理论研究和森林经营实践提供参考。林窗生态学研究集中于林窗的形成、基本特征以及林窗对森林小气候和植物群落特征等地上结构与过程的影响;近年来,林窗对细根与枯落物分解、土壤碳氮动态及酶活性以及对森林动物和土壤微生物的生理生态学特征影响研究逐渐增多,但研究的时空尺度较小且不够全面、深入。今后应着重研究林窗如何调控林分结构和森林生态服务过程与功能,重点阐明林窗对土壤碳氮分配、循环和固持,细根分解及根际效应等地下生态过程,以及对动植物与微生物生理生态学的影响与影响机制;同时,应进一步拓展研究的时空尺度,并加强地上与地下生态系统、生物与非生物因子、宏观与微观尺度等的整合研究。

综述了森林凋落物研究的进展 ,森林凋落物动态的研究随研究方法的改进而不断深化。制约凋落物分解速率的因素有内在因素即凋落物自身的化学物理性质和外在因素即凋落物分解过程发生的外部环境条件 ,如参与分解的异养微生物和土壤动物群落的种类、数量、活性 (生物类因素 )和气候、土壤、大气成分等 (非生物类因素 )。讨论了全球变暖可能引起的凋落物量和凋落物分解的变化。气温上升可能引发植被分布、物候特征和制约凋落物分解因素的改变 ,影响森林凋落物动态 ,最终影响森林生态系统物质循环的功能。

Disturbances in the riparian area had a large effect on each stage of regeneration in riparian forests dominated by Fraxinus platypoda in the Chichibu Mountains, central Japan. F. platypoda adapted well to various disturbances in frequency and size such as landslides and canopy gap formation. The spatial distribution and age structure of F. platypoda were studied in relation to the disturbance regime of the riparian zone. The bell-shaped size and age distributions of F. platypoda suggest that F. platypoda trees were established synchronously in a large disturbance site caused by an earthquake landslide about 200 years ago. For the past 200 years, the topography has been stable and the canopy gap has been recovered by advance regenerated saplings. The distribution of F. platypoda saplings was restricted to an abandoned channel and part of a floodplain. These topographical sites formed by gravel provided safe sites for saplings because stream disturbances did not occur for a long time. Channel bars were under low shade stress because of the lack of herbs and a litter layer, which represents a safe site for seedling establishment. However, the seedling bank could have been destroyed by high frequent flooding caused by large typhoons and the establishment of seedlings might have been prevented for a long time. The regeneration process of F. platypoda was explicated based on the gap dynamics theory during the stable period of topography. On the other hand, an even-aged forest was established in a large scale disturbance site.

Abstract -

As silvicultural objectives have changed over the last several decades, managers are increasingly designing cutting regimes that mimic natural disturbance with the hopes that such systems will restore forests to a more natural condition while optimizing harvest yield. Treefall gaps, canopy openings caused by the death of one or more trees, are the dominant form of disturbance in many forest systems worldwide. These gaps play an important role in forest ecology by helping to maintain bio- and pedo-diversity, influencing nutrient cycling, and preserving the uneven-age nature of late-successional forests. In gap literature, there are inconsistencies with regard to gap terminology, methods for identifying and studying gaps, and modeling gap disturbances. From the papers reviewed, the size of treefall gaps ranges widely from 10 to >5000 m 2; we suggest that the maximum gap size should be set at 1000 m 2. Larger openings tend to have microclimates and return intervals significantly different than smaller treefall gaps. Two main definitions of treefall gaps exist: canopy gap: a ole in the forest through all levels down to an average height of 2 m above ground and extended gap: canopy gap plus the area that extends to the bases of surrounding canopy trees. Although researchers have assumed a variety of gap shapes to simplify measuring gap size, gaps are often irregularly shaped and so we recommend that gap areas and shapes be determined from detailed field measurements. Gap age may be determined from tree ring analysis of released trees in or near the gap edge, the spacing of whorls on released saplings, or from decomposition of gap-making trees. Windthrow is the main cause of canopy gaps in a variety of ecosystems; other causes include insects, diseases, acidic deposition, drought, and climate change. Treefall-gap models have been developed to predict the following processes during gap making or infilling: (i) gap abundance, (ii) forest structure, (iii) spatial and temporal variations in light levels, (iv) canopy dynamics, and (v) soil nutrient and water regimes. We recommend a protocol for gap studies and identify future research topics.

Gap dynamics is the main process by which forest renewal happens in many forest biomes in the world. Under the classical gap dynamics model, only canopy gaps are considered as a dynamic zone. It is also assumed that gapless canopy height change is either uncommon or unimportant for forest dynamics, even though its frequency has never been quantified. In the temperate deciduous forest biome of Quebec, Canada, forest management uses selection cutting to emulate gap dynamics, but little is known about the differences in canopy dynamics between unmanaged and managed forests. Here, we investigated five canopy height change processes: three generating positive height change (canopy growth, gap closure and gap filling) and two generating negative height change (gap creation and canopy height erosion) using multi-temporal LiDAR data in unmanaged and managed (by partial cutting) forests at different periods during the last 2462years. Canopy height erosion, which is canopy height reduction without gap formation, was very common in all studied forests, whatever the gap detection height thresholds used. This canopy process was often more frequent than new canopy gaps and as important in terms of canopy volume reduction. Gap closure rates suggest that canopy gaps will remain more frequent in managed forests 3062years after cuts compared to unmanaged forests. Our results show that it will take at least 3062years after cuts for natural canopy dynamics to recover. We also show that measurements of canopy dynamics processes are sensitive to canopy gap detection height thresholds. This sensitivity is clearly limiting the reproducibility and the comparability of studies in gap ecology.

Several decades of research have shown that canopy gaps drive tree renewal processes in the temperate deciduous forest biome. In the literature, canopy gaps are usually defined as canopy openings that are created by partial or total tree death of one or more canopy trees. In this study, we investigate linkages between tree damage mechanisms and the formation or not of new canopy gaps in northern temperate deciduous forests. We studied height loss processes in unmanaged and managed forests recovering from partial cutting with multi-temporal airborne Lidar data. The Lidar dataset was used to detect areas where canopy height reduction occurred, which were then field-studied to identify the tree damage mechanisms implicated. We also sampled the density of leaf material along transects to characterize canopy structure. We used the dataset of the canopy height reduction areas in a multi-model inference analysis to determine whether canopy structures or tree damage mechanisms most influenced the creation of new canopy gaps within canopy height reduction areas. According to our model, new canopy gaps are created mainly when canopy damage enlarges existing gaps or when height is reduced over areas without an already established dense sub-canopy tree layer.

Do relationships between species and environmental gradients strengthen or weaken with tree life-stage (i.e., small seedlings, large seedlings, saplings, and mature trees)? Strengthened relationships may lead to distinct forest type boundaries, or weakening connections could lead to gradual ecotones and heterogeneous forest landscapes. We quantified the changes in forest dominance (basal area of tree species by life-stage) and environmental factors (elevation, slope, aspect, intercepted photosynthetically active radiation (PAR), summer soil moisture, and soil depth and texture) across 14 forest ecotones (n = 584, 10 m 10 m plots) in Rocky Mountain National Park, Colorado, U.S.A. Local, ecotone-specific species-environment relationships, based on multiple regression techniques, generally strengthened from the small seedling state (multiple R ranged from 0.00 to 0.26) to the tree stage (multiple R ranged from 0.20 to 0.61). At the landscape scale, combined canonical correspondence analysis (CCA) among species and for all tree life-stages suggested that the seedlings of most species became established in lower-elevation, drier sites than where mature trees of the same species dominated. However, conflicting evidence showed that species-environment relationships may weaken with tree life-stage. Seedlings were only found in a subset of plots (habitats) occupied by mature trees of the same species. At the landscape scale, CCA results showed that species-environment relationships weakened somewhat from the small seedling stage (86.4% of the variance explained by the first two axes) to the tree stage (76.6% of variance explained). The basal area of tree species co-occurring with Pinus contorta Doug. ex. Loud declined more gradually than P. contorta basal area declined across ecotones, resulting in less-distinct forest type boundaries. We conclude that broad, gradual ecotones and heterogeneous forest landscapes are created and maintained by: (1) sporadic establishment of seedlings in sub-optimal habitats; (2) survivorship of saplings and mature trees in a wider range of environmental conditions than seedlings presently endure; and (3) the longevity of trees and persistence of tree species in a broad range of soils, climates, and disturbance regimes.

林窗数量特征及其空间分布格局对南亚热带森林生态系统的动态变化、物种共存及生物多样性的维持等具有重要意义。本文基于鼎湖山南亚热带常绿阔叶林20 ha动态监测样地2015年的植被调查数据,结合无人机航拍图像处理技术和地理信息系统,分析了样地内林窗的几何特征和空间分布格局。结果表明:该样地的林窗空隙率为13.72%,密度为35.75个/ha,平均面积38.37 m~2。具体特征有:(1)区域内林窗数量随林窗面积的增加呈负指数分布,整体表现为小林窗多、大林窗少的规律。(2)不同成熟度林分中,过熟林林窗平均面积大于成熟林;成熟林更能体现出小林窗多而大林窗少的特点。(3)各生境林窗分布与大样地整体表现出基本一致的规律,但低谷与其他生境差异显著,林窗平均面积、林窗空隙率等都大于其他生境,而山脊林窗也在林窗空隙率与林窗密度方面低于其他生境。(4)林窗面积和地形因子显著相关:与海拔和凹凸度呈显著负相关;与坡度和坡向呈显著正相关。据此提出建立利用无人机进行森林群落林冠变化与格局的监测体系,是实现林窗与林下群落动态变化同步监测的新手段。

林窗数量特征及其空间分布格局对南亚热带森林生态系统的动态变化、物种共存及生物多样性的维持等具有重要意义。本文基于鼎湖山南亚热带常绿阔叶林20 ha动态监测样地2015年的植被调查数据,结合无人机航拍图像处理技术和地理信息系统,分析了样地内林窗的几何特征和空间分布格局。结果表明:该样地的林窗空隙率为13.72%,密度为35.75个/ha,平均面积38.37 m~2。具体特征有:(1)区域内林窗数量随林窗面积的增加呈负指数分布,整体表现为小林窗多、大林窗少的规律。(2)不同成熟度林分中,过熟林林窗平均面积大于成熟林;成熟林更能体现出小林窗多而大林窗少的特点。(3)各生境林窗分布与大样地整体表现出基本一致的规律,但低谷与其他生境差异显著,林窗平均面积、林窗空隙率等都大于其他生境,而山脊林窗也在林窗空隙率与林窗密度方面低于其他生境。(4)林窗面积和地形因子显著相关:与海拔和凹凸度呈显著负相关;与坡度和坡向呈显著正相关。据此提出建立利用无人机进行森林群落林冠变化与格局的监测体系,是实现林窗与林下群落动态变化同步监测的新手段。

林窗研究是近年来国内外学者关注的热点。笔者从林窗微环境变异及物种对环境变异在物种组成、形态上和生理上以及生长对策的响应几方面 ,阐述了国内外在该领域的研究动态和取得的成果 ,以期推动和促进我国森林动态的研究

林窗研究是近年来国内外学者关注的热点。笔者从林窗微环境变异及物种对环境变异在物种组成、形态上和生理上以及生长对策的响应几方面 ,阐述了国内外在该领域的研究动态和取得的成果 ,以期推动和促进我国森林动态的研究

研究了云南碧塔海两块亚高山云冷杉（Ｐｉｃｅａ－Ａｂｉｅｓ）林内中小尺度林窗的干扰体系，结果表明：林窗和扩展林窗分别占林地面积的１９％和４１％，平均面积为４４ｍ２和１３９ｍ２，林窗的形成频率为０．００５～０．００７／ｙ。估计平均林窗周期为１６７年。大多数林窗（占８７％）的制造林窗树木（ｇａｐ－ｍａｋｅｒ，简记为ＧＭ）为１个以上，平均每个林窗的ＧＭ为２．９个，同一林窗内的ＧＭ常常死于不同的时间。在所有调查的ＧＭ中，折断占６０％，而根拔和直立死亡分别为２８％和１２％

研究了云南碧塔海两块亚高山云冷杉（Ｐｉｃｅａ－Ａｂｉｅｓ）林内中小尺度林窗的干扰体系，结果表明：林窗和扩展林窗分别占林地面积的１９％和４１％，平均面积为４４ｍ２和１３９ｍ２，林窗的形成频率为０．００５～０．００７／ｙ。估计平均林窗周期为１６７年。大多数林窗（占８７％）的制造林窗树木（ｇａｐ－ｍａｋｅｒ，简记为ＧＭ）为１个以上，平均每个林窗的ＧＭ为２．９个，同一林窗内的ＧＭ常常死于不同的时间。在所有调查的ＧＭ中，折断占６０％，而根拔和直立死亡分别为２８％和１２％

对聚果榕小蜂 (Ceratosolensp )传粉生态学进行了首次研究。结果表明 ,聚果榕小蜂的雄蜂比雌蜂早羽化数小时 ;雌蜂羽化不能自行打开瘿花和果肉出蜂口 ,两个出蜂口均需雄蜂开凿。而聚果榕的成熟花粉 ,不能自行地从开裂处散发出来 ,必须经榕小蜂的繁殖性雌蜂采集才能散到表面。羽化后的雌蜂在开裂的雄花中不停地用触角柄节、口器上颚和足推动和采集花粉。雌蜂飞出熟榕果寻找嫩隐头花果 ,一般在外飞翔 5～ 80min。雌蜂进入嫩聚果榕的隐头花果内后 ,立即把粘附在足、头、触角和身上的花粉不停地推动到长柱头雌花中 ,授粉行为长达 4～ 9h。然后 ,才把卵产在短柱头雌花中

林窗是森林生态系统中的一种中小尺度干扰,是促进森林更新、养分循环、功能提高的重要推动力。本文阐述林窗生态学的研究进展与展望,以期为今后的林窗理论研究和森林经营实践提供参考。林窗生态学研究集中于林窗的形成、基本特征以及林窗对森林小气候和植物群落特征等地上结构与过程的影响;近年来,林窗对细根与枯落物分解、土壤碳氮动态及酶活性以及对森林动物和土壤微生物的生理生态学特征影响研究逐渐增多,但研究的时空尺度较小且不够全面、深入。今后应着重研究林窗如何调控林分结构和森林生态服务过程与功能,重点阐明林窗对土壤碳氮分配、循环和固持,细根分解及根际效应等地下生态过程,以及对动植物与微生物生理生态学的影响与影响机制;同时,应进一步拓展研究的时空尺度,并加强地上与地下生态系统、生物与非生物因子、宏观与微观尺度等的整合研究。

对聚果榕小蜂 (Ceratosolensp )传粉生态学进行了首次研究。结果表明 ,聚果榕小蜂的雄蜂比雌蜂早羽化数小时 ;雌蜂羽化不能自行打开瘿花和果肉出蜂口 ,两个出蜂口均需雄蜂开凿。而聚果榕的成熟花粉 ,不能自行地从开裂处散发出来 ,必须经榕小蜂的繁殖性雌蜂采集才能散到表面。羽化后的雌蜂在开裂的雄花中不停地用触角柄节、口器上颚和足推动和采集花粉。雌蜂飞出熟榕果寻找嫩隐头花果 ,一般在外飞翔 5～ 80min。雌蜂进入嫩聚果榕的隐头花果内后 ,立即把粘附在足、头、触角和身上的花粉不停地推动到长柱头雌花中 ,授粉行为长达 4～ 9h。然后 ,才把卵产在短柱头雌花中

西双版纳是中国生物多样性最丰富的地区．国际上确认为重要的生物多样性保护中心，一直是中国生物多样性保护的关键和热点地区，是中国唯一建立热带雨林自然保护区的地区。西双版纳热带雨林是特殊的、罕见的、不可替代的，也是濒危的热带雨林，具有极高的保护价值。早在1959年就开始建立西双版纳国家级自然保护区（2418km^2），并于1993年成为联合国科教文组织（UNESCO）的“人与生物圈”刚络成员。之后，20世纪90年代初，国家环保总局电在其境内建立了西双版纳纳板河流域国家级自然保护区（261km^2），同时，中国科学院西双版纳热带植物园在20世纪70年代初，也对西双版纳热带雨林的植物进行了迁地保护研究，并在20世纪90年代中期率先开展了“中老跨边界生物多样性保护”、“滇南热带雨林保护与乡村持续发展综合研究与示范”等一系列的保护西双版纳热带雨林的行动，进一步加大了对西双版纳热带雨林的保护，也取得了一些重要进展。然而，随着本地区人口的增长、森林的破碎化、社会经济的发展与保护的矛盾的日益加剧．跨边界保护的巨大困难性等，这些问题对西双版纳的热带雨林及其所蕴涵的生物多样性保护都带来直接威胁。因此加强对西双版纳热带雨林的保护势在必行，作者认为应控制经济林比重，提高森林生态效能，加强自然保护区体系网络建设和生物多样性保护，开展跨边界生物多样性研究与保护行动。同时应尊重和运用土著民族的传统知识，使西双版纳热带雨林及其生物多样性得以有效的保护。

西双版纳是中国生物多样性最丰富的地区．国际上确认为重要的生物多样性保护中心，一直是中国生物多样性保护的关键和热点地区，是中国唯一建立热带雨林自然保护区的地区。西双版纳热带雨林是特殊的、罕见的、不可替代的，也是濒危的热带雨林，具有极高的保护价值。早在1959年就开始建立西双版纳国家级自然保护区（2418km^2），并于1993年成为联合国科教文组织（UNESCO）的“人与生物圈”刚络成员。之后，20世纪90年代初，国家环保总局电在其境内建立了西双版纳纳板河流域国家级自然保护区（261km^2），同时，中国科学院西双版纳热带植物园在20世纪70年代初，也对西双版纳热带雨林的植物进行了迁地保护研究，并在20世纪90年代中期率先开展了“中老跨边界生物多样性保护”、“滇南热带雨林保护与乡村持续发展综合研究与示范”等一系列的保护西双版纳热带雨林的行动，进一步加大了对西双版纳热带雨林的保护，也取得了一些重要进展。然而，随着本地区人口的增长、森林的破碎化、社会经济的发展与保护的矛盾的日益加剧．跨边界保护的巨大困难性等，这些问题对西双版纳的热带雨林及其所蕴涵的生物多样性保护都带来直接威胁。因此加强对西双版纳热带雨林的保护势在必行，作者认为应控制经济林比重，提高森林生态效能，加强自然保护区体系网络建设和生物多样性保护，开展跨边界生物多样性研究与保护行动。同时应尊重和运用土著民族的传统知识，使西双版纳热带雨林及其生物多样性得以有效的保护。

The species composition and diversity of soil mesofauna were examined in fragmented dry tropical seasonal rainforest of tow‘Holy Hills' of Dai nationality,compared with the continuous moist tropical seasonal rain forest of Nature Reserve in Xishuangbanna area.5 sample quadrats were selected along the diagonal of 20m×20m sampling plot,and the samples of litterfall and 0～3cm soil were collected from each 50cm×10cm sample quadrat.Animals in soil sample were collected by using dry-funnel(Tullgren's),were identified to their groups according to the order.The H′ index,D·G index and the pattern of relative abundance of species were used to compare the diversity of soil mesofauna.The results showed that the disturbance of vegetation and soil resulted by tropical rainforest fragmentation was the major factor affecting the diversity of soil mesofauna.Because the fragmented forest was intruded by some pioneer tree species and the “dry and warm”effect operated,this forest had more litterfall on the floor and more humus in the soil than the continuous moist rain forest.The soil condition with more soil organic matter,total N and P,higher pH value and lower soil bulk density became more favorable to the soil mesofauna.Therefore,the species richness,abundance and diversity of soil mesofauna in fragmented forests were higher than those in continuous forest,but the similarity of species composition in fragmented forest to the continuous froest was minimal.Soil mesofauna diversity in fragmented forests did not change with decreasing fragmented area,indicating that there was no species-area effect operation in this forest.The pattern of relative abundance of species in these forest soils was logarithmic series distribution.

The species composition and diversity of soil mesofauna were examined in fragmented dry tropical seasonal rainforest of tow‘Holy Hills' of Dai nationality,compared with the continuous moist tropical seasonal rain forest of Nature Reserve in Xishuangbanna area.5 sample quadrats were selected along the diagonal of 20m×20m sampling plot,and the samples of litterfall and 0～3cm soil were collected from each 50cm×10cm sample quadrat.Animals in soil sample were collected by using dry-funnel(Tullgren's),were identified to their groups according to the order.The H′ index,D·G index and the pattern of relative abundance of species were used to compare the diversity of soil mesofauna.The results showed that the disturbance of vegetation and soil resulted by tropical rainforest fragmentation was the major factor affecting the diversity of soil mesofauna.Because the fragmented forest was intruded by some pioneer tree species and the “dry and warm”effect operated,this forest had more litterfall on the floor and more humus in the soil than the continuous moist rain forest.The soil condition with more soil organic matter,total N and P,higher pH value and lower soil bulk density became more favorable to the soil mesofauna.Therefore,the species richness,abundance and diversity of soil mesofauna in fragmented forests were higher than those in continuous forest,but the similarity of species composition in fragmented forest to the continuous froest was minimal.Soil mesofauna diversity in fragmented forests did not change with decreasing fragmented area,indicating that there was no species-area effect operation in this forest.The pattern of relative abundance of species in these forest soils was logarithmic series distribution.

本文系统地介绍了森林循环的理论、自然干扰的概念、林隙的一般特征和林隙干扰的时空格局。干扰是森林循环的驱动力,干扰形成的林隙是森林循环的起点。林隙的大小、形成年龄、形成方式以及形成木的特征是研究林隙特征的重要参数,虽然不同森林群落中,林隙干扰的频率和程度及其时空变化规律不同,但大多数森林的年平均干扰率是在1%左右。不同的森林类型中,大、小型干扰的比例不同。小型林隙干扰与大型灾难性干扰在不同时空条件下的组合,就形成了不同森林景观的时空变化格局。

本文系统地介绍了森林循环的理论、自然干扰的概念、林隙的一般特征和林隙干扰的时空格局。干扰是森林循环的驱动力,干扰形成的林隙是森林循环的起点。林隙的大小、形成年龄、形成方式以及形成木的特征是研究林隙特征的重要参数,虽然不同森林群落中,林隙干扰的频率和程度及其时空变化规律不同,但大多数森林的年平均干扰率是在1%左右。不同的森林类型中,大、小型干扰的比例不同。小型林隙干扰与大型灾难性干扰在不同时空条件下的组合,就形成了不同森林景观的时空变化格局。

本文通过对长白山脉西部蛟河林场3.2hm<SUP>2</SUP>原始红松阔叶林中77个林隙的调查,研究了红松阔叶林中13个主要乔木树种对林隙大小和发育阶段的更新反应规律。结果表明:树种更新密度随林隙大小的变化呈现出单峰型的反应,除沙松、紫椴和花楷槭在林隙面积为40～60m<SUP>2</SUP>时更新密度最大外,其它10个树种的更新密度都在林隙面积为20～40m<SUP>2</SUP>时最大。树种更新密度对林隙发育阶段有单峰型、双峰型和变化不明显3种反应类型。所有树种在林隙内的更新密度都大于其在非林隙林分下的密度。

本文通过对长白山脉西部蛟河林场3.2hm<SUP>2</SUP>原始红松阔叶林中77个林隙的调查,研究了红松阔叶林中13个主要乔木树种对林隙大小和发育阶段的更新反应规律。结果表明:树种更新密度随林隙大小的变化呈现出单峰型的反应,除沙松、紫椴和花楷槭在林隙面积为40～60m<SUP>2</SUP>时更新密度最大外,其它10个树种的更新密度都在林隙面积为20～40m<SUP>2</SUP>时最大。树种更新密度对林隙发育阶段有单峰型、双峰型和变化不明显3种反应类型。所有树种在林隙内的更新密度都大于其在非林隙林分下的密度。

林隙作为森林循环和演替的重要场所,其内小环境特征随着时间和空间而改变,林隙内资源及其空间分布的不均匀性,为物种的共存和更新提供了环境条件,而物种分布的复杂性又进一步促进了森林小环境的异质性分化。本文从小气候状况、土壤及微地形方面对林隙小环境异质性问题进行了论述,并就林隙内微生境因子的异质性分布格局与物种拓殖策略的关系以及边缘效应对物种多样性形成和维持机制的作用等方面进行了阐述。

林隙作为森林循环和演替的重要场所,其内小环境特征随着时间和空间而改变,林隙内资源及其空间分布的不均匀性,为物种的共存和更新提供了环境条件,而物种分布的复杂性又进一步促进了森林小环境的异质性分化。本文从小气候状况、土壤及微地形方面对林隙小环境异质性问题进行了论述,并就林隙内微生境因子的异质性分布格局与物种拓殖策略的关系以及边缘效应对物种多样性形成和维持机制的作用等方面进行了阐述。

61We used a lightweight drone to map in detail forest canopy structure across a 20-ha subtropical forest dynamics plot.61We examined the added benefit of incorporating drone-derived variables in explaining local variation in both stand and species measures.61Drone-derived canopy variables contributed substantially towards explaining spatial patterns in biodiversity.61Species with different light requirements responded to canopy variables supporting gap dynamics successional theories.61Lightweight drone technologies offer great potential for long-term ecological studies.

基于地理信息系统的空间插值是利用离散数据研究地质体及其属性特征的空间分布模式和规律的重要技术方法。本文系统介绍空间插值的原理、工作步骤以及地层学数据在插值中的相关特点，并以华南上扬子区广泛分布的一套碳酸盐岩——奥陶系宝塔组的地层厚度重建为例，介绍反距离权重法、样条函数法和克里格法3种常用插值方法各自的特点。反距离权重法的插值结果位于已知最大值和最小值之间，能保留细节特点，但易出现“牛眼”效应；样条函数的插值结果较平滑，但是预测值会出现超出已知最大值或最小值的现象，因此适用于属性值渐变的情况；克里格法不属于精确性插值，其预测值与实测值之间存在一定的误差，但是能较好地反映数据的整体变化趋势。综合来看，数据点数量越多、分布越均匀、值变化越平缓，插值效果就越好。但在数据条件给定的情况下，根据数据的统计特点和空间分布特征，选择合适的插值方法，是保证插值结果质量的重要前提。

基于地理信息系统的空间插值是利用离散数据研究地质体及其属性特征的空间分布模式和规律的重要技术方法。本文系统介绍空间插值的原理、工作步骤以及地层学数据在插值中的相关特点，并以华南上扬子区广泛分布的一套碳酸盐岩——奥陶系宝塔组的地层厚度重建为例，介绍反距离权重法、样条函数法和克里格法3种常用插值方法各自的特点。反距离权重法的插值结果位于已知最大值和最小值之间，能保留细节特点，但易出现“牛眼”效应；样条函数的插值结果较平滑，但是预测值会出现超出已知最大值或最小值的现象，因此适用于属性值渐变的情况；克里格法不属于精确性插值，其预测值与实测值之间存在一定的误差，但是能较好地反映数据的整体变化趋势。综合来看，数据点数量越多、分布越均匀、值变化越平缓，插值效果就越好。但在数据条件给定的情况下，根据数据的统计特点和空间分布特征，选择合适的插值方法，是保证插值结果质量的重要前提。

正西双版纳雨林深处,存在着一 些传说中的神秘动物,如当地人口中所传的"地皮卷"——如果它吸在人或动物的身体上,会将俘获物的血液吸干为止。雨林中潜藏着植物杀手,比如那外表并不起 眼,却能"见血封喉"的箭毒木。它是世界上最毒、最危险的树木,其乳白色汁液中含有剧毒。"一个民族一朵花",傣族姑娘艳丽的长裙、哈尼人五彩的服饰、拉 祜族古朴的长衫、基诺族素雅的配饰……无不显示出西双版纳民族服饰的多彩。

正西双版纳雨林深处,存在着一 些传说中的神秘动物,如当地人口中所传的"地皮卷"——如果它吸在人或动物的身体上,会将俘获物的血液吸干为止。雨林中潜藏着植物杀手,比如那外表并不起 眼,却能"见血封喉"的箭毒木。它是世界上最毒、最危险的树木,其乳白色汁液中含有剧毒。"一个民族一朵花",傣族姑娘艳丽的长裙、哈尼人五彩的服饰、拉 祜族古朴的长衫、基诺族素雅的配饰……无不显示出西双版纳民族服饰的多彩。

在次生林改造过程中,对林内形成的大小不等的林隙运用班块状造林技术,取得好的效果。运用该项技术不仅使林隙内的目的树种-红松生长发育迅速,并促进了周围次生林木的生长,而且也使草本植物在种类、密度和盖度等方面有了明显的变化。本文就这一问题进行研究,认为光是影响草本植物生长和分布的一个关键因子,林隙对促进草本植物发育,提高物种多样性具有重要意义。

在次生林改造过程中,对林内形成的大小不等的林隙运用班块状造林技术,取得好的效果。运用该项技术不仅使林隙内的目的树种-红松生长发育迅速,并促进了周围次生林木的生长,而且也使草本植物在种类、密度和盖度等方面有了明显的变化。本文就这一问题进行研究,认为光是影响草本植物生长和分布的一个关键因子,林隙对促进草本植物发育,提高物种多样性具有重要意义。

Based on the observation on the radiation with different wavelengths in tropical seasonal rain forest canopy gap,interior of forest,and meteorological station in different seasons,the radiation characteristics of canopy gap were discussed.The results showed that the value of different wavelength radiation had the phenomenon of "suddenly emergent" at the center and north edge of canopy gap.Moreover,each radiation value reached the maximum rapidly,and then decreased quickly around the noon.The daily gross radiation of different wavelengths within the canopy gap was bigger than that in the interior of forest,but smaller than that at meteorological station.Compared to the north edge,the daily gross radiation in the center of the gap was bigger in dry hot season,rain season and later rain season,but smaller in fog cool season,which was influenced by dense fog,solar angle and azimuth.The total daily gross solar radiation at the center was the maximum when the solar angle was the biggest in rain season,higher in later rain season and dry hot season,and was the minimum in fog cool season.The ratios of infrared and visible light radiation to total solar radiation varied with the seasons at the center and north edge of the canopy gap,which fully indicated the environmental heterogeneity within the canopy gap.Compared with meteorological station and interior of forest,the ratios of infrared radiation to total solar radiation in the gap were bigger than those of meteorological station,but smaller than those of interior of forest,which were just contrary to the ratios of visible light to total solar radiation.In addition,the seasonal variation of the ratios of visible light to total solar radiation was higher than that of the ratios of infrared radiation to total solar radiation within the gap.Generally,canopy gap could increase infrared radiation and decrease visible light radiation in tropical seasonal rain forest.

Based on the observation on the radiation with different wavelengths in tropical seasonal rain forest canopy gap,interior of forest,and meteorological station in different seasons,the radiation characteristics of canopy gap were discussed.The results showed that the value of different wavelength radiation had the phenomenon of "suddenly emergent" at the center and north edge of canopy gap.Moreover,each radiation value reached the maximum rapidly,and then decreased quickly around the noon.The daily gross radiation of different wavelengths within the canopy gap was bigger than that in the interior of forest,but smaller than that at meteorological station.Compared to the north edge,the daily gross radiation in the center of the gap was bigger in dry hot season,rain season and later rain season,but smaller in fog cool season,which was influenced by dense fog,solar angle and azimuth.The total daily gross solar radiation at the center was the maximum when the solar angle was the biggest in rain season,higher in later rain season and dry hot season,and was the minimum in fog cool season.The ratios of infrared and visible light radiation to total solar radiation varied with the seasons at the center and north edge of the canopy gap,which fully indicated the environmental heterogeneity within the canopy gap.Compared with meteorological station and interior of forest,the ratios of infrared radiation to total solar radiation in the gap were bigger than those of meteorological station,but smaller than those of interior of forest,which were just contrary to the ratios of visible light to total solar radiation.In addition,the seasonal variation of the ratios of visible light to total solar radiation was higher than that of the ratios of infrared radiation to total solar radiation within the gap.Generally,canopy gap could increase infrared radiation and decrease visible light radiation in tropical seasonal rain forest.

野外数据的获取是生态学研究的挑战之一，而通过遥感技术能够实现对地球表面的多面立体观测，获取丰富多样的空间信息数据，开展从微观到宏观不同尺度上的景观单元（包括物种、种群、群落、生态系统等）的空间关系研究。传统卫星遥感影像受空间和时间分辨率的限制，难以满足局域尺度或者时间序列上的景观空间生态学研究需求。无人机遥感技术为生态学研究的野外数据获取提供了一种新方法，以其灵活、高效、简便等特点弥补了传统卫星遥感的空间分辨率低、重访周期长、云雾影响等方面的不足，在景观空间生态学研究中受到越来越多的关注。简要介绍无人机类型及其搭载常见的传感器类型，分别从不同尺度的景观单元，即物种、种群、群落以及生态系统水平上探讨其应用进展，并指出当前无人机技术在景观生态学研究中存在的挑战与困难，同时展望了未来可能的研究热点，以期对今后无人机遥感技术在景观生态学领域的应用研究有所启发。;Acquiring accurate, spatially explicit data is crucial for ecologists, particularly for long-term landscape and spatial ecological research. Remote sensing techniques have been widely used for collecting data on spatial and temporal ecological phenomena over the last decades. However, owing to the limitations of spatial and temporal resolution of satellite image data, they are sometimes hard to incorporate into regional or local temporal ecological studies. Unmanned aerial vehicles (UAV) remote sensing technology provides a new method for ecological field data acquisition. With its flexibility, efficiency, and convenience, UAV remote sensing technology overcomes the limitations of traditional satellite-based remote sensing in terms of resolution, revisit period, and cloud cover, which has been increasingly focused in studies on landscape ecology. The present study introduced UAV classification and sensor types, in addition to its applications in species, population, community, and ecosystem research. In addition, it pointed out the challenges involved in these applications. We look forward to the promising research area of UAV-based landscape ecology.

野外数据的获取是生态学研究的挑战之一，而通过遥感技术能够实现对地球表面的多面立体观测，获取丰富多样的空间信息数据，开展从微观到宏观不同尺度上的景观单元（包括物种、种群、群落、生态系统等）的空间关系研究。传统卫星遥感影像受空间和时间分辨率的限制，难以满足局域尺度或者时间序列上的景观空间生态学研究需求。无人机遥感技术为生态学研究的野外数据获取提供了一种新方法，以其灵活、高效、简便等特点弥补了传统卫星遥感的空间分辨率低、重访周期长、云雾影响等方面的不足，在景观空间生态学研究中受到越来越多的关注。简要介绍无人机类型及其搭载常见的传感器类型，分别从不同尺度的景观单元，即物种、种群、群落以及生态系统水平上探讨其应用进展，并指出当前无人机技术在景观生态学研究中存在的挑战与困难，同时展望了未来可能的研究热点，以期对今后无人机遥感技术在景观生态学领域的应用研究有所启发。;Acquiring accurate, spatially explicit data is crucial for ecologists, particularly for long-term landscape and spatial ecological research. Remote sensing techniques have been widely used for collecting data on spatial and temporal ecological phenomena over the last decades. However, owing to the limitations of spatial and temporal resolution of satellite image data, they are sometimes hard to incorporate into regional or local temporal ecological studies. Unmanned aerial vehicles (UAV) remote sensing technology provides a new method for ecological field data acquisition. With its flexibility, efficiency, and convenience, UAV remote sensing technology overcomes the limitations of traditional satellite-based remote sensing in terms of resolution, revisit period, and cloud cover, which has been increasingly focused in studies on landscape ecology. The present study introduced UAV classification and sensor types, in addition to its applications in species, population, community, and ecosystem research. In addition, it pointed out the challenges involved in these applications. We look forward to the promising research area of UAV-based landscape ecology.

为了深入理解宝天曼保护区内林窗的形成特征及其形成与林窗边缘木的关系,对核心区内25 hm2固定监测样地的林窗进行了研究.结果表明,样地内林冠林窗(CG)和扩展林窗(EG)分别为36个和46个,CG的平均面积为18.2 m2,以15 m2的数量比最大,而31～45 m2的面积比最大,分别为53%和29%;EG的平均面积为133.6 m2,以101～150 m2的数量比和面积比最大,分别为48%和42%;林窗形成木主要以锐齿槲栎(Quercusaliena)为主,其次是华山松(Pinus armandi)和葛罗槭(Acer grosseri),各占林窗形成木的65.5%,21.8%和3.6%;倒树、枯树或平地是林窗形成的主要原因,各占形成林窗的8.9%,55.6%,5.5%;林窗边缘木主要以锐齿槲栎(Quercus aliena)为主,胸径范围为20～50 cm.

为了深入理解宝天曼保护区内林窗的形成特征及其形成与林窗边缘木的关系,对核心区内25 hm2固定监测样地的林窗进行了研究.结果表明,样地内林冠林窗(CG)和扩展林窗(EG)分别为36个和46个,CG的平均面积为18.2 m2,以15 m2的数量比最大,而31～45 m2的面积比最大,分别为53%和29%;EG的平均面积为133.6 m2,以101～150 m2的数量比和面积比最大,分别为48%和42%;林窗形成木主要以锐齿槲栎(Quercusaliena)为主,其次是华山松(Pinus armandi)和葛罗槭(Acer grosseri),各占林窗形成木的65.5%,21.8%和3.6%;倒树、枯树或平地是林窗形成的主要原因,各占形成林窗的8.9%,55.6%,5.5%;林窗边缘木主要以锐齿槲栎(Quercus aliena)为主,胸径范围为20～50 cm.