Successional Distance between the Source and Recipient Influence Seed Germination and Seedling Survival during Surface Soil Replacement in SW China

Adding propagules (source) to a degraded site (recipient) is a common way of manipulating secondary succession to restore diversity and services formerly provided by forests. However, heretofore no study has considered the effect of “successional distance” between source and recipient site. Four sites in the Shilin karst area of SW China were treated as different states along a secondary successional sere: grass, shrub, young secondary forest, and primary forest. Ten 1 m ×1m soil quadrats in the grass, shrub and young forest sites were replaced with 10 cm deep soil sources from corresponding later successional stage(s) in January 2009. Woody plant seed germination was monitored in the first year and seedling survival was monitored until the end of the second year. At the end of 2010, 2097 seeds of woody plants belonging to 45 taxa had germinated, and 3.9% of the seedlings and 7.8% of the species survived. Germination of most species was sensitive to ambient light (red, far-red, R:FR ratios, photosynthetically active radiation). Soil source and recipient site had a significant effect on the total number of seeds and number of species that germinated, and on the percentage of seedlings that survived through the end of the second year. Closer successional stages between recipient site and soil source had higher seed germination and seedling-survival percentages. However, a transition threshold exists in the young forest state, where seeds can germinate but not survive the second year. Our results, although based on an unreplicated chronosequence, suggest that successional distance between soil sources and recipient sites affect forest recruitment and restoration in degraded karst of SW China.     

Distribution and Population Dynamics of Nematodes in a Rice Field and Pasture in India

Ecological studies on soil nematodes were made in a tropical rice field and pasture. Parasitic species were more diversified in the pasture than in the rice field. Eighty-six and sixty percent of total nematodes occurred in the top 10 cm in rice field and pasture, respectively. Nematodes were not randomly or uniformly dispersed but aggregated. Parasitic forms were most abundant and correlated with root biomass in the 0-15-cm soil layer, the greatest number usually occurring at the 10-15-cm depth at both sites. In summer, however, they were densest at the 15-30-cm depth. Microbivores were most frequent in the top 5 cm of both sites. Micellaneous feeders (food sources uncertain) usually occurred in highest densities at the 15-30-cm depth. Predators showed no distinct depth preference. Temperature and moisture of the soil apparently played an important role in regulating nematode population. Peak densities of 31.3 × 10⁴/m² and 21.6 × 10⁴/m² at a 30-cm depth occurred in January, while minimum densities of 5.0-5.3 × 10⁴/m² and 4.1 × 10⁴/m² occurred in July-October and April in rice field and pasture, respectively. Monthly mean biomass of nematodes was 23.8 ± 4.5 mg/m² in rice field and 11.5 ± 1.5 mg/m² in pasture.     

The Relationship between Species Richness and Evenness in Plant Communities along a Successional Gradient: A Study from Sub-Alpine Meadows of the Eastern Qinghai-Tibetan Plateau,China

The relationship between species richness and evenness across communities remains an unsettled issue in ecology from both theoretical and empirical perspectives. As a result, we do not know the mechanisms that could generate a relationship between species richness and evenness, and how this responds to spatial scale. Here we examine the relationship between species richness(S) and evenness (Pielou’s J′ evenness) using a chronosequence of successional sub-alpine meadow communities in the eastern Qinghai-Tibetan Plateau. These meadows range from natural community (never farmed), to those that have been protected from agricultural exploitation for periods ranging from 1 to 10 years. A total of 30 sampling quadrats with size of 0.5 m×0.5 m were laid out along two transects at each meadow. Using correlation analyses we found a consistent negative correlation between S and J′ in these communities along the successional gradient at the sampling scale of 0.5 m×0.5 m. We also explored the relationship between S and J′ at different sampling scales (from 0.5 m×0.5 m to10 m×10 m) using properly measured ramet-mapped data of a10 m×10 m quadrat in the natural community. We found that S was negatively corrected with J′ at the scales of 0.5 m×0.5 m to 2 m×2 m, but such a relationships disappeared at relative larger scales (≥2 m×4 m). When fitting different species abundance models combined with trait-specific methods, we found that niche preemption may be the determining mechanism of species evenness along the succession gradient. Considering all results together, we can conclude that such niche differentiation and spatial scale effects may help to explain the maintenance of high species richness in sub-alpine meadow communities.     

Structure of mixed ombrophyllous forests with Araucaria angustifolia (Araucariaceae) under external stress in Southern Brazil

This study is part of the Floristic and Forest Inventory of Santa Catarina, conceived to evaluate forest resources, species composition and structure of forest remnants, providing information to update forest conservation and land use policy in Southern Brazilian State of Santa Catarina (95 000 km2). In accordance to the Brazilian National Forest Inventory (IFN-BR), the inventory applies systematic sampling, with 440 clusters containing four crosswise 1 000m2 plots (20 x 50m) each, located on a 10 x 10km grid overlaid to land use map based on classification of SPOT-4 images from 2005. Within the sample units, all woody individuals of the main stratum (DBH > or = 10cm) are measured and collected (fertile and sterile), if not undoubtedly identified in field. Regeneration stratum (height > 1.50m; DBH < 10cm) is registered in 100m2 in each sample unit. Floristic sampling includes collection of all fertile trees, shrubs and herbs within the sample unit and in its surroundings. This study performs analysis based on 92 clusters measured in 2008 within an area of 32320km2 of mixed ombrophyllous forests with Araucaria angustifolia located at the state's high plateau (500m to 1 560m above sea level at 26 degrees 00'-28 degrees 30' S and 49 degrees 13'-51 degrees 23' W). Mean density (DBH > or = 10cm) is 578 individuals/ha (ranging from 85/ha to 1 310/ha), mean species richness in measured remnants is 35 (8 to 62), Shannon and Wiener diversity index (H') varies between 1.05 and 3.48. Despite high total species diversity (364 Magnoliophyta, five Coniferophyta and one tree fern) and relatively high mean basal area (25.75m2/ha, varying from 3.87 to 68.85m2/ha), the overwhelming majority of forest fragments are considered highly impacted and impoverished, mostly by logging, burning and extensive cattle farming, turning necessary more efficient protection measures. Basal area was considered an appropriate indicator for stand quality and conservation status.     

Patterns of Biomass and Carbon Distribution across a Chronosequence of Chinese Pine (Pinus tabulaeformis) Forests

Patterns of biomass and carbon (C) storage distribution across Chinese pine (Pinus tabulaeformis) natural secondary forests are poorly documented. The objectives of this study were to examine the biomass and C pools of the major ecosystem components in a replicated age sequence of P. tabulaeformis secondary forest stands in Northern China. Within each stand, biomass of above- and belowground tree, understory (shrub and herb), and forest floor were determined from plot-level investigation and destructive sampling. Allometric equations using the diameter at breast height (DBH) were developed to quantify plant biomass. C stocks in the tree and understory biomass, forest floor, and mineral soil (0–100 cm) were estimated by analyzing the C concentration of each component. The results showed that the tree biomass of P. tabulaeformis stands was ranged from 123.8 Mg·ha^–1 for the young stand to 344.8 Mg·ha^–1 for the mature stand. The understory biomass ranged from 1.8 Mg·ha^–1 in the middle-aged stand to 3.5 Mg·ha^–1 in the young stand. Forest floor biomass increased steady with stand age, ranging from 14.9 to 23.0 Mg·ha^–1. The highest mean C concentration across the chronosequence was found in tree branch while the lowest mean C concentration was found in forest floor. The observed C stock of the aboveground tree, shrub, forest floor, and mineral soil increased with increasing stand age, whereas the herb C stock showed a decreasing trend with a sigmoid pattern. The C stock of forest ecosystem in young, middle-aged, immature, and mature stands were 178.1, 236.3, 297.7, and 359.8 Mg C ha^–1, respectively, greater than those under similar aged P. tabulaeformis forests in China. These results are likely to be integrated into further forest management plans and generalized in other contexts to evaluate C stocks at the regional scale.     

Distribution of millipedes (Myriapoda,Diplopoda) along a forest interior – forest edge – grassland habitat complex

We studied the distribution of millipedes in a forest interior-forest edge-grassland habitat complex in the Hajdúság Landscape Protection Area (NE Hungary). The habitat types were as follows: (1) lowland oak forest, (2) forest edge with increased ground vegetation and shrub cover, and (3) mesophilous grassland. We collected millipedes by litter and soil sifting. There were overall 30 sifted litter and soil samples: 3 habitat types × 2 replicates × 5 soil and litter samples per habitats. We collected 9 millipede species; the most abundant species was Glomeris tetrasticha, which was the most abundant species in the forest edge as well. The most abundant species in the forest interior was Kryphioiulus occultus, while the most abundant species in the grassland was Megaphyllum unilineatum. Our result showed that the number of millipede species was significantly lower in the grassland than in the forest or in the edge, however there were no significant difference in the number of species between the forest interior and the forest edge. We found significantly the highest number of millipede individuals in the forest edge. There were differences in the composition of the millipede assemblages of the three habitats. The results of the DCCA showed that forest edge and forest interior habitats were clearly separated from the grassland habitats. The forest edge habitat was characterized by high air temperature, high soil moisture, high soil pH, high soil enzyme activity, high shrub cover and low canopy cover. The IndVal and the DCCA methods revealed the following character species of the forest edge habitats: Glomeris tetrasticha and Leptoiulus cibdellus. Changes in millipede abundance and composition were highly correlated with the vegetation structure.     

Addressing regional relationships between white‐tailed deer densities and land classes

White‐tailed deer (Odocoileus virginianus) populations have recovered to about 30 million animals in the United States, but land cover has changed during the interval of recovery. To address the relationship between deer densities and current land cover at regional scales, I applied random forests and extreme gradient boosting classifiers to model low and high deer density classes, at two different thresholds (5.8 and 11.6 deer/km²), and land classes in three regions during approximately 2003. For low and high deer density classes divided at 5.8 deer/km², deciduous broadleaf forest overall was the most influential and positive variable in the central east and central regions and crop and pasture were the most influential and negative variables in the southeast region. Deer density increased with area of deciduous and mixed forests, woody wetlands, and shrub in all regions. Deer density decreased with area of crop, developed open space, and developed low and medium residential density in all regions. For density classes divided at 11.6 deer/km², deer density had the strongest relationship with woody wetlands in the central east region, mixed and deciduous forest in the southeast region, and woody wetlands and herbaceous vegetation in the central region. Deer density increased with deciduous and mixed forests, woody wetlands, and shrub in all regions. Conversely, deer density decreased with herbaceous vegetation, crop, and developed low residential densities in all regions. Therefore, at regional scales, deer overall occurred at greater densities in forests and woody wetlands and lower densities in agricultural and residential development, which did not appear to support more deer. Deer preference for forests does result in damage to forest products, but alternatively, some may consider that deer provide important socioeconomic and ecological services by reducing number of small trees, particularly in the absence of other disturbances that historically controlled tree biomass.     

Assessing scale‐dependent effects on Forest biomass productivity based on machine learning

Estimating forest above‐ground biomass (AGB) productivity constitutes one of the most fundamental topics in forest ecological research. Based on a 30‐ha permanent field plot in Northeastern China, we modeled AGB productivity as output, and topography, species diversity, stand structure, and a stand density variable as input across a series of area scales using the Random Forest (RF) algorithm. As the grain size increased from 10 to 200 m, we found that the relative importance of explanatory variables that drove the variation of biomass productivity varied a lot, and the model accuracy was gradually improved. The minimum sampling area for biomass productivity modeling in this region was 140 × 140 m. Our study shows that the relationship of topography, species diversity, stand structure, and stand density variables with biomass productivity modeled using the RF algorithm changes when moving from scales typical of forest surveys (10 m) to larger scales (200 m) within a controlled methodology. These results should be of considerable interest to scientists concerned with forest assessment.     

Accumulation and Connectivity of Coarse Woody Debris in Partial Harvest and Unmanaged Relict Forests

When a tree dies, it continues to play an important ecological role within forests. Coarse woody debris (CWD), including standing deadwood (SDW) and downed deadwood (DDW), is an important functional component of forest ecosystems, particularly for many dispersal-limited saproxylic taxa and for metapopulation dynamics across landscapes. Processes, such as natural disturbance or management, modify forest composition and structure, thereby influencing CWD abundance and distribution. Many studies have compared older forests to forests managed with even-aged silvicultural systems and observed a prolonged period of low CWD occurrence after harvesting. With fine-scale spatial data, our study compares the long-term impacts of light partial harvesting on the CWD structure of eastern deciduous hardwood forests. We mapped and inventoried DDW and SDW using variable radius plots based on a 10 m×10 m grid throughout an unmanaged, structurally-complex relict forest and two nearby forests that were partially harvested over 46 years ago. The relict stand had significantly larger individual pieces and higher accumulations of DDW and SDW than both of the partially harvested stands. Connectivity of CWD was much higher in the relict stand, which had fewer, larger patches. Larger pieces and higher proportion of decay-resistant species (e.g. Quercus spp.) in the relict forest resulted in slower decomposition, greater accumulation and increased connectivity of CWD. Partial harvests, such that occur with selection forestry, are generally considered less disruptive of ecosystem services, but this study highlights the long-term impacts of even light partial harvests on CWD stocks and distribution. When planning harvesting events, forest managers should also consider alternative methods to ensure the sustainability of deadwood resources and function.     

广东韶关小坑林场5种阔叶林林下植物多样性

对韶关市小坑林场的山杜英Elaeocarpus sylvestris、樟树Cinnamomum camphora、黧蒴Castanopsis fissa、红椎Castanopsis hystrix和火力楠Michelia macclurei纯林的林下植被多样性进行研究。结果表明,山杜英林、樟树林、黧蒴林、红椎林、火力楠林下灌木层分别有12、7、16、10、9种植物,草本层分别有13、11、12、14、20种植物。5种阔叶林样地的物种多样性存在差异, 部分灌木层的物种多样性高于草本层的多样性。山杜英林灌木层的Shannon-Wiener多样性指数及均匀度指数(Jsw和Jsi)分别为2.51、0.70、0.86,高于其他树种的灌木层多样性指数,表明林分种类在林下植物分布格局中起着重要作用,山杜英林有利于林下植物的发育。     

Long-Term Effects of Forest Regrowth and Selective Logging on the Seed Bank of Tropical Forests in NE Costa Rica1.

To investigate long-term effects of land use on the soil seed bank, we compared the abundance/density, species richness, life form distribution, and species composition of seeds stored in the soil of four 15–20 yr-old second-growth stands, two old-growth stands, and two previously selectively-logged stands in the Caribbean lowlands of Costa Rica. Surface soil (10 cm deep, 4.7 cm diameter) was collected at 10 m intervals along three 120–160 m long transects in each stand (44–48 soil cores, 22–24 combined seed bank samples per site). Seed density was highest but variable in second-growth stands (8331–14535 seeds/m²), low and homogeneous in old-growth stands (2258–2659 seeds/m²), and intermediate and highly variable in selectively-logged stands (1165–6854 seeds/m²), which also had contrasting logging intensities. Species richness was strongly dependent on seed density, but showed less variation. Life form distribution did not differ statistically among or within land-use categories. In each stand, herbs-forbs, shrubs, and vines dominated the seed bank (> 75% of the species richness and abundance), whereas trees were a minor component (< 20% of the species richness and < 5% of the abundance) and were predominandy early successional. Shrubs and vines were most abundant in second-growth stands where regrowth vegetation was repeatedly cut before abandonment, whereas grasses and sedges were most abundant in the only forest stand that was completely surrounded by pastures. In terms of species composition, old-growth stands were more similar to selectively-logged stands than to second-growth stands, but across stands, selectively-logged forests were most distinct from the other two forest types. An inventory of the standing woody vegetation in each site showed little representation of the woody taxa found in the seed bank. We discuss these results in the context of the main factors that have been postulated to influence the abundance, life form, and species composition of tropical forest seed banks, and explore the role of the latter during intermediate phases of tropical forest succession and regeneration.     

贵州中部喀斯特山地不同植被生态系统细根生态特征及养分储量

为了解喀斯特生态系统退化过程中树木细根生物量和土壤养分的变化,选择贵州中部喀斯特山地乔木林、灌木林和灌草丛3种植被生态系统,比较分析不同深度(0～5 cm、5～10 cm和10～15 cm)土壤细根数量及其养分情况.结果表明:树木细根主要分布在0～10 cm土层,并随土层加深而减少.在0～10 cm土层中,乔木林、灌木林和灌草丛的活细根生物量分别占0～15 cm总细根生物量的42.78%、56.75%和53.38%,总活细根生物量的83.36%、86.91%和93.79%.不同植被下优势种植物细根生物量存在差异.0～5 cm土层乔木林活细根氮素和磷素储量均显著高于灌草丛和灌木林(P0.05),但灌木林和灌草丛间没有差异;5～10 cm土层乔木林活细根氮和磷储量显著高于灌草丛和灌木林(P0.05),灌木林下又显著高于灌草丛下(P0.05).0～10 cm土层的活细根生物量与植株地上部分生物量呈正相关,植物叶片氮、磷养分含量与细根比根长呈显著的负相关,说明细根的养分储量对地上生物量的建成和生态系统功能的发挥具有重要作用.     

Woody plants' diversity,structural analysis and regeneration status of Wof Washa natural forest,North‐east Ethiopia

Wof‐Washa forest is one of the few remaining dry Afromontane forests in the central plateau of Ethiopia. Woody species composition, structure and regeneration patterns of this forest were studied to generate information essential for formulating feasible management options for the forest. Vegetation data were collected from 64 quadrats of size 20 m × 20 m, 10 m × 10 m and 5 m × 5 m for tree/shrub, sapling and seedling, respectively, laid systematically along transects. A total of 62 woody species belonging to 54 genera and 40 families were recorded. Rosaceae was the most diverse family with five (12.5%) species followed by Anacardiaceae, Euphorbiaceae and Myrsinaceae with three (7.5%) species each. Tree/shrub, sapling and seedling densities were 699, 1178 and 7618.7 individuals/ha. About 56.7% of the importance value index was contributed by Juniperus procera, Maytenus arbutifolia, Podocarpus falcatus and Ilex mitis. Vegetation classification resulted in five plant communities: Ilex mitis – Maytenus obscura, Galiniera saxifraga – Maesa lanceolata, Juniperus procera – Erica arborea, Podocapus falcatus – Allophylus abyssinicus and Pittosporum viridiflorum – Polycias fulva community types. Regeneration status of all the woody plant species was categorized as ‘Good’ (28%), ‘Fair’ (19%), ‘Poor’ (8%), ‘None’ (40%) and ‘New’ (5%).     

湖南八大公山25 ha常绿落叶阔叶混交林动态监测样地群落组成与空间结构

湖南八大公山国家级自然保护区位于武陵山系北缘, 区内分布有大面积的常绿落叶阔叶混交林, 物种多样性丰富, 群落结构复杂。中国科学院武汉植物园按CTFS (Center for Tropical Forest Sciences)建设规范于2010-2011年在保护区内建设了一个25 ha的动态监测样地, 为亚热带山地森林群落多样性长期动态监测提供了理想的平台。本文初步分析了八大公山25 ha样地的群落组成与空间结构。结果表明: 群落内共有木本植物存活个体186,575株, 隶属于53科114属232种; 个体数超过1,000株的有38个物种(贡献87%的个体数), 个体数最多的物种为黄丹木姜子(Litsea elongata); 样地内稀有种(≤ 25株)种数占样地总物种数的44%, 而个体数仅为样地总个体数的0.4%。样地内个体平均胸径为5.41 cm, 其中68.4%的个体DBH ≤ 5 cm, DBH ≥ 20 cm的个体数(7,474株)仅约占总个体数的4%; 个体胸径直方图呈倒“J”形, 表明样地处于良好更新与正常生长状态。样地的种-面积关系图显示物种数随样地面积的增加而同步增加, 其增长速度由迅速增长逐渐趋于稳定, 取样面积10 ha时可以涵盖90%以上的物种; 1 ha小样地个体数平均为7,261.8 ± 974.8 (SD), 物种数平均为128.2 ± 8.2 (SD), Shannon-Wiener指数平均为3.56 ± 0.11 (SD), Pielou均匀度指数变异最小, 平均为1.69 ± 0.06 (SD); 个体数与各多样性指数均无显著相关, 表明在该样地中物种多样性的取样效应不明显, 物种数量增加的原因可能来自于其他因素的控制。     

关帝山寒温性云杉次生林样地树种组成、结构和空间分布

云杉次生林是关帝山的优势森林植被类型,也是华北亚高山地区寒温性常绿针叶林的代表类型.为更好地了解其物种组成、群落结构等基本特征及其潜在的生态学过程和机制,于2010年在关帝山庞泉沟国家自然保护区建立了4 hm²的云杉次生林固定监测样地(GDS样地).本文以第一次本底调查数据为基础,分析了样地树种组成、结构和空间分布.结果表明: 样地共有木本植物30种,隶属于11科22属.包括分枝的总个体数为26218(其中独立个体数为10266).植物区系组成属北温带成分;不同树种个体数、平均胸径和胸高断面积差异较大,导致群落成层分明,各层优势种明显.乔木层第一亚层树种径级结构呈双峰偏正态分布,乔木层第二亚层树种径级呈近似正态分布,灌木层树种径级呈“L”型分布.乔木优势树种青杄和华北落叶松的空间分布无论在个体数量还是聚集程度上均随径级变化而呈现不同的格局特征.相同径级的两树种,胸径(DBH)≥30 cm的华北落叶松在样地居多且聚集分布于样地中部,而DBH≥30 cm的青杄则相对较少,没有表现出空间聚集性.DBH≤10 cm的华北落叶松个体很少且散生于样地,而DBH≤10 cm的青杄大量聚集于样地中部.DBH≤10 cm的青杄在样地偏西北区域也有大量分布,而DBH≤10 cm的红桦主要分布于样地偏东南区域.灰栒子、土庄绣线菊和四川忍冬等灌木树种也表现出一定的异质性空间分布特征.树种分布格局受生境条件影响,同时与自身发育规律、更新特征及生态习性等相关.     

Effects of logging and coarse woody debris harvest on lepidopteran communities in the eastern deciduous forest of North America

相似文献   

滇中喀斯特森林土壤种子库的种-面积关系

土壤中的种子是植物群落更新与再恢复的种源基础。国内对土壤种子库的取样面积与种子检出之间的关系还很少涉及。在采用萌发方法对采集自滇中喀斯特山地的100个10 cm×10 cm小样方的物种数进行研究后,分析了土壤种子库的种-面积关系。面积与总物种和乔、灌、草本物种数之间的关系与二次方程和对数方程之间的拟合关系都较好。总物种数和草本物种数的基数较大且随面积增长较明显,而乔木和灌木的基数相对较小,增长较慢。总物种数的增加在面积位于0.15~0.2 m²,也即15~20个10 cm×10 cm样方之间时逐渐趋缓,可将这一面积和取样数量作为同类地区种子库取样的参考。     

林分因子对神木垒不同森林群落林下植物多样性的影响

为探究神木垒不同森林群落林下植物多样性的差异,本研究采用典型样地法,以夹金山神木垒的5种主要森林群落：云杉林、丽江云杉林、红杉林、针阔混交林、阔叶林为研究对象,对不同森林群落林下植物物种组成和物种多样性进行比较,并对林分因子和林下植物多样性进行冗余分析,确定影响林下植物多样性的主要林分因子,为当地森林经营管理提供理论依据。结果表明：（1）在研究区内共记录林下植物147种,隶属于61科,108属;云杉林群落林下植物的科属种组成最丰富。（2）各类型群落的H值、H"值、D值、JSW值均为：草本层＞灌木层;灌木层多样性最高的群落为云杉林群落,草本层多样性最高的群落为丽江云杉林群落,针阔混交林群落、阔叶林群落林下植物多样性较差。（3）平均枝下高与林分密度是影响灌木层物种多样性的主要林分因子（P<0.01）,平均枝下高与灌木层的D值、H值、H"值呈负相关关系,林分密度与灌木层4个多样性指数均呈正相关关系;平均枝下高是影响草本层物种多样性的主要林分因子（P<0.01）,平均枝下高与草本层H值、H"值、JSW值呈正相关关系。本研究认为,云杉林群落与丽江云杉林群落的林下植物多样性水平较高,平均枝下高与林分密度是影响神木垒不同森林群落林下植物多样性的主要林分因子。     

Light heterogeneity affects understory plant species richness in temperate forests supporting the heterogeneity–diversity hypothesis

One of the most important drivers for the coexistence of plant species is the resource heterogeneity of a certain environment, and several studies in different ecosystems have supported this resource heterogeneity–diversity hypothesis. However, to date, only a few studies have measured heterogeneity of light and soil resources below forest canopies to investigate their influence on understory plant species richness. Here, we aim to determine (1) the influence of forest stand structural complexity on the heterogeneity of light and soil resources below the forest canopy and (2) whether heterogeneity of resources increases understory plant species richness. Measures of stand structural complexity were obtained through inventories and remote sensing techniques in 135 1‐ha study plots of temperate forests, established along a gradient of forest structural complexity. We measured light intensity and soil chemical properties on six 25 m² subplots on each of these 135 plots and surveyed understory vegetation. We calculated the coefficient of variation of light and soil parameters to obtain measures of resource heterogeneity and determined understory plant species richness at plot level. Spatial heterogeneity of light and of soil pH increased with higher stand structural complexity, although heterogeneity of soil pH did not increase in conditions of generally high levels of light availability. Increasing light heterogeneity was also associated with increasing understory plant species richness. However, light heterogeneity had no such effects in conditions where soil resource heterogeneity (variation in soil C:N ratios) was low. Our results support the resource heterogeneity–diversity hypothesis for temperate forest understory at the stand scale. Our results also highlight the importance of interaction effects between the heterogeneity of both light and soil resources in determining plant species richness.     

Fauna community trends during early restoration of alluvial open forest/woodland ecosystems on former agricultural land

Vertebrate fauna was studied over 10 years following revegetation of a Eucalyptus tereticornis ecosystem on former agricultural land. We compared four vegetation types: remnant forest, plantings of a mix of native tree species on cleared land, natural regeneration of partially cleared land after livestock removal, and cleared pasture land with scattered paddock trees managed for livestock production. Pasture differed significantly from remnant in both bird and nonbird fauna. Although 10 years of ecosystem restoration is relatively short term in the restoration process, in this time bird assemblages in plantings and natural regeneration had diverged significantly from pasture, but still differed significantly from remnant. After 10 years, 70 and 66% of the total vertebrate species found in remnant had been recorded in plantings and natural regeneration, respectively. Although the fauna assemblages within plantings and natural regeneration were tracking toward those of remnant, significant differences in fauna between plantings and natural regeneration indicated community development along different restoration pathways. Because natural regeneration contained more mature trees (dbh > 30 cm), native shrub species, and coarse woody debris than plantings from the beginning of the study, these features possibly encouraged different fauna to the revegetation areas from the outset. The ability of plantings and natural regeneration to transition to the remnant state will be governed by a number of factors that were significant in the analyses, including shrub cover, herbaceous biomass, tree hollows, time since fire, and landscape condition. Both active and passive restoration produced significant change from the cleared state in the short term.