Effects of topography and management history on natural forest recovery in abandoned forest after clear-cutting in Miyazaki, Japan

We investigated factors limiting the recovery of natural forest in former large-scale conifer plantations abandoned after clear-cutting in southwestern Japan. We analyzed forest recovery status (“recovered” sites covered by evergreen broad-leaved trees, and “unrecovered” sites covered by pioneer community or nonvegetated sites) using aerial photographs and field survey. We applied logistic regression analyses to evaluate the effects of topography, construction of harvesting roads, distance from remnant forest, stand condition before clear-cutting, and prior land-use history on forest recovery. Human factors, i.e., land use and clear-cutting age, were found to affect to forest recovery more than environmental factors such as topography. Harvesting roads had the strongest negative impact on forest recovery. Forest recovery after clear-cutting of young sugi plantations also took longer than after clear-cutting of old sugi plantations or evergreen broad-leaved forests. Furthermore, areas formerly utilized as meadows recovered less successfully than those that had been managed as coppices. The influences of these factors were thought to be promoted by the advance reproduction as the regeneration sources for forest recovery. The influence of stand age before logging suggested an effect of thinning, which might alter the abundance of advanced reproduction in the understory. However, distance from remnant forest appeared to be less important. An influence of topography was also detected, but this could be partly explained by the existence of advance reproduction in the understory in certain topographic positions. Thus, our analysis suggests that regeneration sources originating from advanced reproduction in plantations play a significant role for the recovery of natural forest after clear-cutting.     

Influence of distance to forest edges on natural regeneration of abandoned pastures: a case study in the tropical mountain rain forest of Southern Ecuador

In spite of its high diversity the forests in Southern Ecuador are highly endangered by deforestation. One of the main reasons for the loss of forests is the conversion into pastures. Due to their fast degradation, the pastures are abandoned after several years and form an increasing area of unproductive land. The remoteness from existing forest edges is discussed as one reason for the very slow natural reforestation of these areas. In this study we analyzed the regeneration of a secondary forest after approx. 38 years of succession in relation to the distance from the surrounding forest. We revealed that regeneration was rather slow. Especially larger trees with dbh > 10 cm were very scarce. Only Dioicodendron dioicum, Graffenrieda emarginata and Clusia sp. achieved larger diameters. The basal area of the secondary forest is still far beyond the original level in the primary forest. The number of species on plot level and the Shannon index were significantly lower in the secondary forest compared to the primary forest. The total number of species decreased from 47 to 31 with increasing distance from the forest edge and the similarity of species composition to the upper story declined to a level of 56.4 (Sörensen). Alzatea verticillata, Macrocarpea revoluta and Palicourea andaluciana had significantly higher abundances in the succession stages than in the natural forest. The most abundant species in all regeneration plots, G. emarginata and Purdiea nutans, seem to be generalists as they did not show preference either to natural forest or successional stages.     

尼加拉瓜废弃农田的森林恢复年代序列分析

对废弃4年、9年和14年的3块废弃农田的木本植物物种组成、植物密度和种群结构的恢复情况进行了表征.在每块废弃地上,建立70个100 m2样地,鉴别和计数幼苗、幼树和成年树.在4年龄林分中有13科17物种,9年龄林分中有29科48物种,14年龄林分中有22科44物种.在不同的演替阶段,林分中优势种不同.Lonchocarpus acuminatus在4年龄林分中重要值最高,Myrospermun frutescens、榆梧桐和破布木在9年龄林分中重要值最高;Caesaeria cotymbosa、南美假樱桃、墨西哥丁香和红花风铃木在14年龄林分中重要值最高.从4年龄到14年龄的废弃地,总的立木度从5011株/hm2增加到9631株/hm2.胸径在1cm以上的植株总的基面积也随废弃农田年龄增加而增加.总的来讲,小的植株(胸径小于10cm)的基面积超过总的基面积的一半.9年龄林分物种丰富度最高,14年龄和4年龄林分次之.总之,相比于林分结构属性,次生林植物种类构成可以快速恢复到成熟林水平,这与热带干旱森林总的演替趋势是相一致的.     

Growth of native forest species planted on abandoned pasture land in Costa Rica

Many forest plantations in the humid neo-tropics are established on degraded soils in abandoned pasture land and, with some exceptions, the species planted have not grown successfully. Studies of adaptability and growth under these conditions are scarce, particularly for native species. In this paper we present data on growth and tree form at 3 years of age for 11 species planted in abandoned pastures. The research plantation was established at La Selva Biological Station, in the Atlantic lowlands of Costa Rica (10° 26′N, 83° 59′W). Survival, diameter at breast height (DBH), total height, basal area, volume index and tree form were used to evaluate the species performance. After 3 years, Vochysia guatemalensis displayed a survival significantly higher (98%) than that of the other species. The lowest survival was 75% for Pinus tecunumanii. There were significant differences in growth measures among species. Acacia mangium exhibited significantly higher growth rates than the other species. Although this species grew rapidly, it did not develop straight single stems. About 14% of trees of A. mangium had bifurcation below DBH and more than 50% showed multiple axes or branches as large in diameter as the principal axis. The native species with the highest growth rate was Vochysia guatemalensis (DBH 12.7 cm, total height 7.5 m, volume index 55 m³ ha⁻¹ at 3 years of age). Vochysia ferruginea exhibited a slightly lower growth rate. Both Vochysia species were ranked highly with regard to tree form, with more than 80% straight single stemmed trees. The lowest growth rates were exhibited by Pentaclethra macroloba, Pithecellobium macradenium and Virola koschnyi; however, the latter two species formed straight single terms. Pentaclethra macroloba and Inga edulis failed to form straight single stems. In general, the growth rates of the species studied were high in comparison with results reported from other tree plantations in the tropics. In spite of this, it is not prudent to draw final conclusions on the basis of these 3 year measurements.     

辽西地区不同人工林地土壤肥力变化研究

为研究辽西地区人工林对石灰性褐土土壤质量的定向改良作用,以油松×沙棘混交林、山杏纯林、油松纯林3种人工林地为研究对象,对在石灰性褐土上的人工林土壤肥力进行了分析。结果表明,油松沙棘混交林能够显著提高有机碳含量,比荒地高42.8%;油松沙棘混交林、油松纯林土壤碱解氮分别比荒地增加34.6%和33.6%,人工林对土壤全氮含量影响不显著;油松沙棘混交林的土壤速效磷和水溶性磷分别比荒地提高14.9%和128.57%;人工林增加了土壤速效钾含量;林木的改良土壤作用主要表现在土壤表层。     

不同林龄水杉人工林下土壤微生物量的变化研究

研究了上海市水杉人工林林下土壤中有机碳、全氮和土壤微生物量碳氮含量.结果显示:沿海地区水杉人工林表层土壤(0～10cm)的有机碳和全氮含量均处于一个比较低的水平,随着林龄的逐渐增大,其含量逐渐变大.土壤微生物量碳占有机碳的比例在0.18%～1.42%,处于-个较低水平;土壤微生物量氮占全氮含量的0.19%～7.04%,...     

Natural systems as models for the design of sustainable systems of land use

Natural ecosystems, whose components are the results of natural selection, are sustainable; most are productive, responsive to pests, and retentive of nutrients. Thus, they are appropriate models on which to base the design of new systems of land use. Abiotic and biotic stressors are related non-linearly; the nadir of total stress being mid-way along a gradient of environmental harshness. Superimposing the stress functions on Holdridge's life zone chart yields four broad categories of environments for agriculture: climates where annual rainfall is similar to potential evapotranspiration, plus three other categories that are either too cold, too arid, or too wet. Extremely cold lands have no potential for agriculture. Lands that are arid or infertile can be used successfully, although the cost of compensating for environmental limitations increases exponentially with increasing abiotic stress. Grazing animals (which act as trophic buffers between people and environment) have proven successful in dry and infertile environments. The humid tropical lowlands epitomise environments of low abiotic stress but overwhelming biotic intricacy. Here it pays to imitate natural systems rather than struggle to impose simplicity on ecosystems that are inherently complex. The keys to success are to (i) channel productivity into outputs of nutritional and economic importance, (ii) maintain adequate diversity to compensate for losses in a system simple enough to be horticulturally manageable, (iii) manage plants and herbivores to facilitate associational resistance and not associational susceptibility, and (iv) use perennial plants to maintain soil fertility, guard against erosion, and make full use of resources. This revised version was published online in June 2006 with corrections to the Cover Date.     

辽东山区退耕还林地植被恢复调查研究

辽东山区是辽宁省重要的水源涵养基地和中部城市群的天然绿色屏障,在退耕还林过程中选择不同的植被恢复模式对退耕地植被群落的发育演替、生态功能的发挥具有不同的作用。文章通过对草河口退耕还林监测场植被恢复不同模式连续3年的调查研究认为,辽东山区在坡耕地退耕之初的几年内,植被自然恢复比较快,生态功能也比较强,但人工辅助措施能加快植被恢复进程,尤其是乔灌模式植被群落发育最好,为生态功能的发挥提供了必要的物质基础。     

Genetic diversity of Lithocarpus harlandii populations in three forest communities with different succession stages

By using random amplified polymorphic DNA (RAPD) technique, this paper studied the genetic diversity and genetic differentiation of Lithocarpus harlandii populations in three forest communities (coniferous forest, coniferous and broad-leaved mixed forest, and evergreen broad-leaved forest) with different succession stages in Tiantai Mountain in Zhejiang Province. The results showed that a total of 173 repetitive loci were produced in 60 individuals of L. harlandii by 12 random primers, among which, 152 loci were polymorphic, and the total percentage of polymorphic loci was 87.86%. The average percentage of polymorphic loci of the populations was 65.32%, and their total genetic diversity estimated by Shannon information index was 0.4529, with an average of 0.3458, while that judged from Nei’s index was 0.3004, with an average of 0.2320. The percentage of polymorphic loci, Shannon information index, and Nei’s index of the populations were in the sequence of coniferous forest community > coniferous and broad-leaved mixed forest community > evergreen broad-leaved forest community. Analysis of molecular variance (AMOVA) showed that 72.85% of genetic variance was found within the populations, and 27.15% of genetic variance resided among the populations. The coefficient of gene diferentiation was 0.2277, and the gene flow was 1.6949. The genetic structure of L. harlandii was influenced not only by the biological characteristics of this species, but also by the microenvironment of different communities. The mean of genetic identity among three populations of L. harlandii was 0.8662, and the mean of their genetic distance was 0.1442. The genetic similarity between coniferous and broad-leaved mixed forest community and evergreen broad-leaved forest community was the highest, while that between evergreen broad-leaved forest community and coniferous forest community was the lowest. The unweighted pair group method with arithmeticmean (UPGMA) cluster analysis based on Nei’s genetic distance showed that conierous and broad-leaved mixed forest community first gathered with evergreen broad-leaved forest community, and then with coniferous forest community. __________ Translated from Chinese Journal of Ecology, 2007, 26(4): 509–514 [译自: 生态学杂志]     

保护区外围保护地带建设项目使用林地可行性探讨

依据保护区外围保护地带建设项目使用林地调查结果,阐明建设项目使用林地的必要性,分析了使用林地条件因素,提出了使用林地方案与保障措施。     

Fire history recorded on pine trunks and stumps: Influence of land use and fires on forest structure in North Karelia

Dendrochronological dating of fire scars was used to determine the history of forest fires, and the effects of the fires and of slash‐and‐burn cultivation on forest structure were studied in eastern Finland. A total of 67 fire years were dated over an area of 26 km². Forest fires increased towards the end of the 17th century and again towards the end of the 18th century, but decreased markedly in the middle of the 19th century. The mean fire interval was shorter near the historically known slash‐and‐burn cultivation areas than elsewhere. A forest survey map from 1913 was used to reconstruct the forest structure after the cessation of slash‐and‐burn cultivation and forest fires. This map showed that most of the younger forests were situated near old slash‐and‐burn cultivation areas, while the older forests were situated farther away from these. The proportion of deciduous trees decreased with increasing distance from slash‐and‐burn cultivation areas.     

Carbon stock changes of forest land in Finland under different levels of wood use and climate change

Context

Prediction of the effect of harvests and climate change (CC) on the changes in carbon stock of forests is necessary both for CC mitigation and adaptation purposes.

Aims

We assessed the impact of roundwood and fuelwood removals and climate change (CC) on the changes in carbon stock of Finnish forests during 2007–2042. We considered three harvest scenarios: two based on the recent projections of roundwood and fuelwood demand, and the third reflecting the maximum sustainable cutting level. We applied two climate scenarios: the climate was in the state that prevailed around year 2006, or it changed according to the IPCC SRES A1B scenario.

Methods

We combined the large-scale forestry model MELA with the soil carbon model Yasso07 for mineral soils. For soils of drained, forested peatlands, we used a method based on emission factors.

Results

The stock change of trees accounted for approximately 80 % of the total stock change. Trees and mineral soils acted as carbon sinks and the drained peatland soils as a carbon source. The forest carbon sink increased clearly in both of the demand-based scenarios, reaching the level of 13–20 Tg C/year (without CC). The planned increase in the use of bioenergy reduced the forest sink by 2.6 Tg C/year. CC increased the forest carbon sink in 2042 by 38 %–58 % depending on the scenario. CC decreased the sink of mineral soils in the initial years of the simulations; after 2030, the effect was slightly positive. CC increased the emissions from the drained peatland soils.

Conclusions

It is likely that forest land in Finland acts as a carbon sink in the future. The changes in carbon stocks of trees, mineral soils, and peatland soils respond differently to CC and fuelwood and roundwood harvests.     

The effects of cultivation history on forest recovery in fallows in the Eastern Arc Mountain, Tanzania

Using fallows under shifting cultivation systems as a case study, we examined the effects of landuse history (cultivation duration and cropping strategies) on rate and extent of forest recovery. Cultivation duration and five cropping strategies were investigated post facto, indirectly, and with regards to their effect on the structure (basal area, BA and stand complexity, C_HCI) and diversity (Fisher's α) of forests in fallows. Data were generated from vegetation surveys conducted in the Nguru Mountain block of the Eastern Arc Mountains, Tanzania. The surveys were conducted in primary forests, ongoing farms, and fallows that had been out of production for 1-31 years (N = 109, plot size = 0.1 ha). Recovery patterns between lowland (300-800 m) and submontane (800-1600 m) elevations varied substantially. BA and C_HCI recovery levels were consistently higher in submontane fallows. None of the fallows had attained BA and C_HCI levels equivalent to those of primary forests; α in lowland fallows, however, was 124% of primary forest levels. Forest recovery was limited to fallows whose cultivation period was ≤16 years. Recovery was fastest and highest in fallows located within a dense primary/old growth forest matrix. The findings provide a more thorough understanding of how local farming practices affect forest recovery. Improving the recovery outcomes of fallows that are located outside the old growth forest matrix will require (a) more strategic inclusion of remnant trees, (b) drastically shorter cultivation periods, and (c) human intervention through assisted regeneration.     

湖北省林地使用权流转情况调查与思考

为全面了解湖北省林地流转现状,2002年3～6月,湖北省范围内开展了一次林地使用权流转(以下简称林地流转)专题调研。通过调查,得到三点基本结论:一是湖北省林地流转发展势头强劲,效果显著,潜力巨大;二是林地流转亟待相应的政策支撑和法律规范,存在的问题不容忽视;三是林地流转给各级林业部门改进工作方法、加强资源监管提出了新的要求。     

Genetic diversity of Quercus glandulifera var. brevipetiolata populations in three forest communities with different succession stages

In order to understand the relationship between population succession and its genetic behavior, random amplified polymorphic DNA (RAPD) technique was used to analyze the genetic diversity of Quercu glandulifera var. brevipetiolata populations in three forest communities with different succession stages (coniferous forest, coniferous and broad-leaved mixed forest, evergreen broad-leaved forest). The results showed that 145 repetitive loci were produced in 60 individuals of Q. glandulifera using 11 primers, among which 120 loci were polymorphic, and the total percentage of polymorphic loci was 82.76% with an average of 64.14%. Estimated by the Shannon information index, the total genetic diversity of the three populations was 0.4747, with an average of 0.3642, while it was 0.3234, with an average of 0.2484, judged from the Nei index. Judged from percentage of polymorphic loci, Shannon inform at ion index and Nei index, the genetic diversity followed a decreasing order: coniferous forest > broad-leaved mixed forest > evergreen broad-leaved forest. Analysis of molecular variance (AMOVA) showed that 69.73% of the genetic variance existed within populations and 30.27% of the genetic variance existed among populations. The coefficient of gene differentiation (GST) was 0.2319 and the gene flow (N _m) was 1.6539. The mean of genetic identity among populations of Q. glandulifera was 0.8501 and the mean of genetic distance was 0.1626. The genetic identity between the Q. glandulifera population in the coniferous forest and that in the coniferous and broadleaved mixed forest was the highest. UPGMA cluster analysis based on Nei’s genetic distance showed that the population in the coniferous forest gathered with that in the coniferous and broad-leaved mixed forest firstly, then with that in the evergreen broad-leaved forest. The genetic structure of Q. glandulifera was not only characteristic of the biological characteristics of this species, but was also influenced by the microenvironment in different communities. __________ Translated from Journal of Northwest Forestry University, 2008, 23(1): 18–22 [译自: 西北林学院学报]     

Microbiological parameters as indicators of soil organic carbon dynamics in relation to different land use management

Labile C fractions: microbial biomass C (MBC), K₂SO₄ extractable C ( \textC_{\textK 2 \textSO 4} {\text{C}}_{{{\text{K}}_{ 2} {\text{SO}}_{ 4} }} ) and the cumulated mineralized C in 21 days incubation at 28°C (C–CO_2(21d)), were compared as land use indicators in a calcareous soil under three different management systems: native Querqus ilex forest (under and outside tree cover), a Pinus halepensis plantation, and cropped land (with cereals). Microbial biomass and activity were found to be low and coincided with high carbonate contents. As indicators of land use, \textC_{\textK 2 \textSO 4} {\text{C}}_{{{\text{K}}_{ 2} {\text{SO}}_{ 4} }} and C–CO_2(21d) showed the same sensitivity as MBC. C–CO₂ emissions were measured in an incubation experiment in order to study C mineralization kinetics. The data for cumulative amounts of C–CO₂ released showed a good fit (R ² > 0.94) to the first-order kinetic model C _m = C _o(1 − e^−kt ). The kinetic parameters C _o and C _o k were affected by land use and especially by tree cover. Principal components analysis was applied to the data and the relationship among microbial metabolic quotient (qCO₂), labile C pools, and MBC revealed a decrease in efficiency of organic substrate utilization with an increase in availability and lability of the organic matter.     

火干扰对天然红松林结构和演替过程的影响

Investigations on charcoal in the soil, fire-scarred trees, stand composition, forest structure as well as regeneration status were carried out in the natural broad-leaved/Korean pine (Pinus koraiensis) forest after fire disturbance at Liangshui Nature Reserve on the mid-north of Xiaoxing‘an Mountains from 1990 to 1992, and the ecological effects of fire disturbance on the formation and succession of this kind of forest were analyzed according to the survey results. The average depth of charcoal in the soil was related to the timing of the fire. According to the characteristic of fire-scarred trees, the dynamic map of the fire behavior was drawn onto the topographic map. It showed that the dimension and extent of the fire disturbance was closely related with site conditions. Fire disturbance only led to a significant difference in stand composition and diameter class structurefor the stands at different locations, rather than completely destroying the forest. After fire disturbance, the horizontal community structure was a mosaic of different patches, which were made up of different deciduous species or different sizes of Korean pines, and the succession trend of each patch was also different. In the sites with the heavy fire disturbance, the intolerant hardwood species were dominant, and there were a large number of regenerative Korean pine saplings under the canopy. In the moderate -disturbed sites, the tolerant hardwood species were dominant, and a small number of large size Korean pines still survived. In the light-disturbed sites, large size Korean pines were dominant.     

张北县退耕还林还草地域选择

退耕还林还草是当前生态环境建设和保护的主要途径。本文以河北省试点县张北县为研究对象,分析了退耕还林与可持续发展的关系问题,并在GIS的支持下,探讨了张北县退耕还林还草的地域选择问题,主要包括地域选择基本单元、选择方法、退耕地分析等问题,以期为合理实施退耕提供科学依据。     

Hillside forest land as a safety net for local people in a mountain village in West Java: an examination of differences in the significance of national and private lands

 In Kemang, a mountain village in West Java, Indonesia, the local people call the hillsides pasir, a term which includes both privately owned hillside land or nationally owned forest land. It is apparent that the national forest lands function as a social safety net, serving as land where the middle-class and the poor can conduct “informal” cultivation, through temporary agreements with the state forestry corporation, or even “illegal” cultivation without permission. In this study, the households cultivating on national forest lands were identified as: (1) having most household members living together; (2) having a relatively young head person; (3) cultivating a small area of rice field; (4) having participated in the former perhutanan sosial system; (5) being dependent on the income from hillside land; (6) taking advantage of the rare opportunities for off-farm income; and (7) having a low total income. Meanwhile, the talun-huma system is dominant on privately owned hillside land, where a part of the talun, or tree garden, is cleared for use as a swidden on a 30-year rotation. In such cases, the land functions as a safety net only for the limited number of people who are permitted access to the land. The function of the privately owned hillside land, through the mutual-aid system, should not be overestimated; it is probably less important than national forest land in terms of income redistribution. It is recommended that the government of Indonesia consider the possibility of formally ensuring the long-term rights of local people to utilize the national forest lands in Java. Received: April 6, 2001 / Accepted: October 24, 2002 Acknowledgments This paper is in part a result of the research activities of the Core University Program in Applied Bioscience between the University of Tokyo and Bogor Agricultural University, sponsored by the Japan Society for the Promotion of Science (JSPS). The authors would like to express their thanks to Prof. Sumiaki Iwamoto, the University of Tokyo, for his kind help. Correspondence to:M. Inoue