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Tree survival and maximum density of planted forests–Observations from South African spacing studies

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Forest Ecosystems 2015年第1期2卷 11-19页

作者： klaus v.gadow Heyns Kotze Department of Forest and Wood Science University of Stellenbosch University of G?ttingen Mondi South Africa Division Hilton South Africa

Background：Among the most important aspects of risk and hazard studies relating to forest ecosystems are maximum forest density and density-dependent tree ***：Long-term observations about the maximum density of unthinned Pinus patula and *** field plots based on the Correlated Curve Trend（CCT）spacing studies which were established almost 8 decades ago by O’Connor（Forest Research with Special Reference to Planting Distances and Thinning,1935）in South *** specific approaches were introduced for analysing maximum density and tree survival,namely the‘limiting line’,Nilson’s sparsity and tree survival with the Weibull ***：The main results are：a）Maximum densities differ greatly among the two species grown on the same site and within the same species grown on different sites;it is possible to relate these differences to site index in both species.b）The relationship between the quadratic mean diameter and the minimum average spacing of surviving trees（known as Nilson’s Sparsity）appears to be surprisingly similar in both species.c）An analysis of tree survival in response to different initial planting espacements shows that the Weibull survival function parameters can be estimated if the initial planting density is *** result is presented for each of the eight large experiments used in this ***：This study contributes to a better understanding of tree survival and maximum density which are the key factors required for estimating risk and *** risk of tree mortality is not constant,but varies with tree species,planting density,tree age and growing *** estimating that risk,therefore,continuous long-term observation on different sites and with varying planting densities,as provided by the unthinned CCT series,are essential.

关键词： Self-thinning Mortality CCT Pinus patula Pinus elliottii South Africa Nelder

Diversity and production in an Afromontane Forest

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Forest Ecosystems 2016年第4期3卷 275-286页

作者： klaus v.gadow GongQiao Zhang Graham Durrheim David Drew Armin Seydack Georg-August University in Gottingen Gottingen Germany Department of Forestry and Wood Science University of Stellenbosch Stellenbosch South Africa Chinese Academy of Forestry in Beijing Beijing China South African National Parks Knysna South Africa

Background：This contribution evaluates the effect of forest structure and tree species diversity on plot productivity and individual tree growth in the unique Knysna forests in Southern Africa using mapped tree data from an observational study that has been re-measured over a period of 40 ***：The effects of tree species diversity and forest structure on tree growth and forest production are evaluated on three levels of resolution：a） the forest community（canopy,sub-canopy species）,b） the subplots（number of trees per ha,skewness of the diameter distribution,diameter coefficient of variation） and c） the immediate neighborhood of selected reference trees（＂Mingling＂,＂Dominance＂,Aggregation＂ and ＂Size variation＂）.Results：An analysis of the community level identified two distinct clusters,one including dominant/canopy species with the highest growth rates and a greater variation of growth,and another cluster which includes the remaining subcanopy species which have a smaller maximum size and lower rates of *** area-based structure variables on plot level have a highly significant effect on total basal area ***,the effects of forest density and species richness on productivity were not straight *** basal area production of about 0.75 m^2/ha/year is achieved at medium levels of richness（around 20 species per ha） and medium levels of density（around 30 m^2/ha basal area） using percentile regression *** relative ＂Dominance＂ of a selected reference tree had a highly significant effect on individual tree growth on all investigated *** neighbourhood structure variables were only occasionally significant or not significant at ***：This contribution presents a new theoretical framework for analysing natural forests that includes community,plot and neighborhood variables of forest structure and diversity,and a first specific analysis of the structure and dynamics of the Knysna Afromontane Forest,based on a unique s

关键词： canopy neighborhood forests richness basal straight productivity occasionally remaining tropical

The national forest inventory in China:history-results-international context

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Forest Ecosystems 2015年第4期2卷 288-303页

作者： Wei Sheng Zeng Erkki Tomppo Sean P.Healey klaus v.gadow Academy of Forest Inventory and Planning State Forestry Administration Natural Resources Institute Finland Forest Service United States Department of Agriculture University of G?ttingen Beijing Forestry University Department of Forestry and Wood Technology University of Stellenbosch

Background： National forest resource assessments Inventories （NFI＇s）, constitute an important nationa and monitoring, commonly known as National Forest information infrastructure in many countries. Methods： This study presents details about developments of the NFI in China, including sampling and plot design and the uses of alternative data sources, and specifically · reviews the evolution of the national forest inventory in China through the 20th and 21st centuries, with some reference to Europe and the US; · highlights the emergence of some common international themes： consistency of measurement; sampling designs; implementation of improved technology; expansion of the variables monitored more efficient scientific transparency;· presents an example of how China＇s expanding NFI exemplifies these global trends. Results： Main results and important changes in China＇s NFI are documented, both to support continued trend analysis and to provide data users with historical perspective. Conclusions： New technologies and data needs ensure that the Chinese NFI, like the national inventories in other countries, will continue to evolve. Within the context of historical change and current conditions, likely directions for this evolution are suggested.

关键词： China Europe USA National forest inventories Forest inventory and analysis

Tree growth decline to warm-wet conditions in boreal forests is linked to stand density

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FOREST ECOSYSTEMS 2025年第1期12卷 74-82页

作者： Zhao, Bingqian Zhu, Yihong Gao, Lushuang Zhang, Qibing Liu, Mingqian von gadow, klaus Beijing Forestry Univ Res Ctr Forest Management Engn State Forestry Grassland Adm Beijing 100083 Peoples R China Beijing Forestry Univ State Forestry & Grassland Adm Key Lab Forest Reso Beijing 100083 Peoples R China Univ Calif Berkeley Dept Environm Sci Policy & Management Berkeley CA 94704 USA Chinese Acad Sci Inst Bot State Key Lab Vegetat & Environm Change Beijing 100093 Peoples R China Univ Ghent Lab Wood Technol Coupure links 653 B-9000 Ghent Belgium Georg August Univ Gottingen Fac Forestry & Forest Ecol Busgenweg 5 D-37077 Gottingen Germany Stellenbosch Univ Fac Agrisci Dept Forestry & Wood Sci Stellenbosch Private Bag X1 ZA-7602 Stellenbosch South Africa

Warm-wet climatic conditions are widely regarded as conducive to remarkable tree growth, alleviating climatic pressures. However, the notable decline in tree growth observed in the southern edge of boreal forests has heightened concerns over the spatial-temporal dynamics of forest decline. Currently, attaining a comprehensive grasp of the underlying patterns and their propelling factors remains a formidable challenge. We collected tree ring samples from a network of 50 sites across the Greater Xing'an Mountains. These samples were subsequently grouped into two distinct clusters, designated as Groups A and B. The percentage change of growth (GC, %) and the proportion of declining sites were utilized to assess forest decline. The decline in tree growth within Larix gmelinii forests exhibits significant regional variation, accompanied by temporal fluctuations even within a given region. Group A exhibited a pronounced increase in frequency (59.26%) of occurrences and encountered more severe declines (21.65%) in tree growth subsequent to the 1990s, contrasting sharply with Group B, which observed lower frequencies (20.00%) and relatively less severe declines (21.02%) prior to the 1980s. The primary impetus underlying the opposite radial growth increments observed in Larix gmelinii trees from the interplay between their differential response to temperatures and wetter climatic conditions, which is significantly influenced by varying stand densities. In cold-dry conditions, low-density forests may experience soil water freezing, exacerbating drought conditions and thereby inhibiting tree growth, in Group B. Trees growth in high-density stands is restrained by warm-wet conditions, in Group A. These results provide new insights into the variability at the southern edge of the boreal forest biome with different responses to density and climate.

关键词： Growth decline Stand density The southern edge of boreal forests Larix gmelinii

Tree growth decline to warm-wet conditions in boreal forests is linked to stand density

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Forest Ecosystems 2025年第1期 74-82页

作者： Bingqian Zhao Yihong Zhu Lushuang Gao Qibing Zhang Mingqian Liu klaus von gadow Research Center of Forest Management Engineering of State Forestry and Grassland Administration Beijing Forestry University State Forestry and Grassland Administration Key Laboratory of Forest Resources&Environmental Management Beijing Forestry University Department of Environmental Science Policy and ManagementUniversity of California State Key Laboratory of vegetation and Environmental Change Institute of BotanyChinese Academy of Sciences Laboratory of Wood Technology Ghent University Faculty of Forestry and Forest Ecology Georg-August-University G?ttingen Department of Forestry and Wood Science Faculty of AgriSciencesStellenbosch University

Warm-wet climatic conditions are widely regarded as conducive to remarkable tree growth, alleviating climatic pressures. However, the notable decline in tree growth observed in the southern edge of boreal forests has heightened concerns over the spatial-temporal dynamics of forest decline. Currently, attaining a comprehensive grasp of the underlying patterns and their propelling factors remains a formidable challenge. We collected tree ring samples from a network of 50 sites across the Greater Xing'an Mountains. These samples were subsequently grouped into two distinct clusters, designated as Groups A and B. The percentage change of growth(GC, %) and the proportion of declining sites were utilized to assess forest decline. The decline in tree growth within Larix gmelinii forests exhibits significant regional variation, accompanied by temporal fluctuations even within a given region. Group A exhibited a pronounced increase in frequency(59.26%) of occurrences and encountered more severe declines(21.65%) in tree growth subsequent to the 1990s, contrasting sharply with Group B, which observed lower frequencies(20.00%) and relatively less severe declines(21.02%) prior to the 1980s. The primary impetus underlying the opposite radial growth increments observed in Larix gmelinii trees from the interplay between their differential response to temperatures and wetter climatic conditions, which is significantly influenced by varying stand densities. In cold-dry conditions, low-density forests may experience soil water freezing,exacerbating drought conditions and thereby inhibiting tree growth, in Group B. Trees growth in high-density stands is restrained by warm-wet conditions, in Group A. These results provide new insights into the variability at the southern edge of the boreal forest biome with different responses to density and climate.

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Book review “Wattles: Australian Acacia species around the world” by David M. Richardson, Johannes J. Le Roux and Elizabete Marchante

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Forest Ecosystems 2024年第2期11卷 140-141页

作者： klaus von gadow Faculty of Forestry and Forest Ecology Georg-August-University GöttingenBüsgenweg 5D-37077GöttingenGermany Department of Forestry and Wood Science Faculty of AgriSciencesStellenbosch UniversityStellenbosch Private Bag X1Stellenbosch7602South Africa

In a world of Google and AI, developing an encyclopedic coverage of a theme that is of great interest to biologists, social scientists, politicians and environmental managers, is a daunting challenge. Wattles is a book that presents new knowledge, makes interesting reading, and has the potential to stimulate research in a variety of disciplines. We learn that Acacia, commonly known as the wattles or acacias, is a genus of shrubs and trees comprising 1,083 species of which 417 are known to have been introduced to areas outside their native range. We are surprised to read that Australian acacias are found almost everywhere, in virtually all terrestrial habitats, including woodlands, grasslands, alpine settings,rainforests, coastal dunes and deserts, causing major environmental and socio-economic changes in the invaded regions. Until recently, Acacia comprised a group of plant species native to Africa, South America and Australasia, but the name is now reserved for species predominantly from Australia, including some from Southeast Asia. The genus name Acacia is Neo-Latin, and refers to a preparation extracted from the leaves and fruit pods of vachellia nilotica, the original type of the genus.

关键词： Richardson outside Latin

Structure complexity is the primary driver of functional diversity in the temperate forests of northeastern China

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Forest Ecosystems 2022年第4期9卷 511-520页

作者： Zhenghua Lian Juan Wang Chunyu Fan klaus von gadow Research Center of Forest Management Engineering of State Forestry and Grassland Administration Beijing Forestry UniversityBeijing100083China Department of Forest Ecology School of Ecology and Nature ConservationBeijing Forestry UniversityBeijing100083China Faculty of Forestry and Forest Ecology Georg-August-University G€ottingenBüsgenweg 5D-37077GottingenGermany Department of Forest and Wood Science University of StellenboschStellenbosch7600South Africa

Background:Assessing functional diversity to identify its spatial patterns and drivers is an important step towards understanding the adaptive capacity of ecosystems to environmental change. However, until now, these mechanisms were poorly understood in the temperate forests of northeastern China, which prevented the development of new management methods aimed at increasing functional trait diversity and thus ecological ***:In this study, we mapped functional diversity distributions using a Kriging Interpolation Method. A specific random forest model approach was adopted to test the importance ranking of 18 variables in explaining the spatial variation of functional diversity. Three piecewise structural equation models (pSEMs) with forest types as random effects were constructed for testing the direct effects of climate, and the indirect effects of stand structure on functional diversity across the large study region. Specific causal relationships in each forest type were also examined using 15 linear structural equation ***:Although environmental filtering by climate is important, stand structure explains most of the functional variation of the forest ecosystems in northeastern China. Our study thus only partially supports the stressdominance hypothesis. Several abundant species determine most of the functional diversity, which supports the mass ratio ***:Our results suggest that forest management aimed at increasing structural complexity can contribute to increased functional diversity, especially regarding the mixing of coniferous and broad-leaved tree species.

关键词： Functional diversity distribution Forest types Forest management Random forest Stand structure attributes Structural equation modeling

Climate change effects in the Western Himalayan ecosystems of India: evidence and strategies

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Forest Ecosystems 2017年第3期4卷 232-240页

作者： vindhya Prasad Tewari Raj Kumar verma klaus von gadow Himalayan Forest Research Institute Georg-August University Department of Forestry and Wood Science University of Stellenbosch

Background： The fragile landscapes of the Himalayan region are highly susceptible to natural hazards, and there is ongoing concern about current and potential climate change impacts. This study provides background information on India＇s Western Himalayas and reviews evidence of warming as well as variability in precipitation and extreme ***： Understanding and anticipating the impacts of climate change on Himalayan forest ecosystems and the services they provide to people are critical. Efforts to develop and implement effective policies and management strategies for climate change mitigation and adaptation requires particular new research initiatives. The various studies initiated and conducted in the region are compiled ***： Several new initiatives taken by the Himalayan Forest Research Institute in Shimla are described. This includes new permanent observational field studies, some with mapped trees, in high altitude transitional zones for continuous monitoring of vegetation response. We have also presented new strategies for mitigating potential climate change effects in Himalayan forest ***： Assessment of the ecological and genetic diversity of the Himalayan conifers is required to evaluate potential responses to changing climatic conditions. Conservation strategies for the important temperate medicinal plants need to be developed. The impact of climate change on insects and pathogens in the Himalayas also need to be assessed. Coordinated efforts are necessary to develop effective strategies for adaptation and mitigation.

关键词： Himalayan ecosystem Climate change New strategies High altitude New observational studies

Mismatch between species distribution and climatic niche optima in relation to functional traits

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Forest Ecosystems 2022年第6期9卷 813-822页

作者： Zhenghua Lian Juan Wang Chunyu Zhang Xiuhai Zhao klaus von gadow Research Center of Forest Management Engineering of State Forestry and Grassland Administration Beijing Forestry UniversityBeijing100083China Department of Forest Ecology School of Ecology and Nature ConservationBeijing Forestry UniversityBeijing100083China Faculty of Forestry and Forest Ecology Georg-August-University GottingenBüsgenweg 5D-37077GottingenGermany Department of Forest and Wood Science University of StellenboschStellenbosch7600South Africa

Background:Forecasts of climate change impacts on biodiversity often assume that the current geographical distributions of species match their niche ***,empirical evidence has challenged this assumption,suggesting a *** examine whether the mismatch is related to functional traits along temperature or precipitation ***:The observed distributions of 32 tree species in northeast China were evaluated to test this *** models were used to estimate the climatic niche optima,*** habitats where the highest species growth and density can be *** mismatch is defined as the difference between the actual species occurrence in an assumed niche optimum and the habitat with the highest probability of species ***’functional traits were used to explore the mechanisms that may have caused the ***:Contrasting these climatic niche optima with the observed species distributions,we found that the distribution-niche optima mismatch had high variability among species based on temperature and precipitation ***,these mismatches depended on functional traits associated with competition and migration lags only in temperature ***:We conclude that more relevant research is needed in the future to quantify the mismatch between species distribution and climatic niche optima,which may be crucial for future designs of forested landscapes,species conservation and dynamic forecasting of biodiversity under expected climate change.

关键词： Demography Functional traits Mean annual temperature Mean annual precipitation Niche theory Species distribution