A bibliometric analysis using machine learning to track paradigm shifts and analytical advances in forest ecology and forestry journal publications from 2010 to 2022

Forest habitats are critical for biodiversity,ecosystem services,human livelihoods,and well-being.Capacity to conduct theoretical and applied forest ecology research addressing direct(e.g.,deforestation)and indirect(e.g.,climate change)anthropogenic pressures has benefited considerably from new field-and statistical-techniques.We used machine learning and bibliometric structural topic modelling to identify 20 latent topics comprising four principal fields from a corpus of 16,952 forest ecology/forestry articles published in eight ecology and five forestry journals between 2010 and 2022.Articles published per year increased from 820 in 2010 to 2,354 in 2021,shifting toward more applied topics.Publications from China and some countries in North America and Europe dominated,with relatively fewer articles from some countries in West and Central Africa and West Asia,despite globally important forest resources.Most study sites were in some countries in North America,Central Asia,and South America,and Australia.Articles utilizing R statistical software predominated,increasing from 29.5%in 2010 to 71.4%in 2022.The most frequently used packages included lme4,vegan,nlme,MuMIn,ggplot2,car,MASS,mgcv,multcomp and raster.R was more often used in forest ecology than applied forestry articles.R software offers advantages in script and workflow-sharing compared to other statistical packages.Our findings demonstrate that the disciplines of forest ecology/forestry are expanding both in number and scope,aided by more sophisticated statistical tools,to tackle the challenges of redressing forest habitat loss and the socio-economic impacts of deforestation.

Does ash dieback affect the reproductive ecology of Fraxinus excelsior L.?

Forest tree species reproduction is a key factor in maintaining the genetic diversity of future generations and the stability of forest ecosystems.The ongoing ash dieback disease could affect the reproductive ecology of Fraxinus excelsior L.and have a major impact on the quantity and quality of pollen and seeds.In this study,we investigated pollen production and viability of pollen and seeds of ash trees with different health status from 2018 to 2022.Inflorescences were collected from 105 trees(pollen production),pollen from 125 trees(pollen viability),and seeds from 53 trees(seed quality)in two seed orchards and in one floodplain forest in southern Germany.Not all parameters were examined at every site every year.The average pollen production per tree was estimated at 471.2±647.9 billion pollen grains.In addition,we found that a high number of inflorescences did not equate to high pollen production per inflorescence.Pollen production of healthy and diseased trees did not differ significantly,although only 47%of severely diseased male trees(vs.72%for healthy trees)produced flowers.With regards to pollen viability,the TTC test showed an average viability of 73%±17%.Overall,there was a slight tendency for diseased trees to have less viable pollen.However,a significant difference could only be calculated for trees in the floodplain forest.The percentage of germinable seeds in 2018 was 38%in the floodplain forest and 57%in one of the seed orchards.The percentage of viable seeds(TTC test)ranged from 17 to 22%in the orchards in 2020.Non-viable seeds were usually heavily infested by insects.In general,seed quality was not significantly different between healthy and diseased trees.Our results indicate that ash dieback affects flower formation and pollen viability but not pollen production or seed quality.Nevertheless,the fact that hardly any flowering was observed,especially for trees that were seriously affected,suggests a negative effect of ash dieback on reproductive performance.Thus,severely diseased trees will transfer their genes to a smaller extent to the next generation.

The Theory of Soil and Water Ecology is a Major Scientific Issue

The theory of soil and water ecology is an important scientific issue related to the fundamental and overall situation of ecological environment and has important strategic significance for the protection of the earth’s ecological environment.Applying the theory of soil and water ecology to soil and water conservation can upgrade soil and water conservation from version 1.0 to version 2.0 of soil and water ecological conservation and further expand the space of soil and water conservation.The paper suggests that while giving full play to the existing strength of soil and water conservation departments,it should establish national soil and water conservation commission for coordinating multi sector forces and vigorously promoting the realization of beautiful and rich China.

The Theory of Soil and Water Ecology is the Common Theoretical Basis in the Field of Ecological Environment

From the perspective of system concept and practical needs,the field of ecological environment needs new theories that can grasp the whole and command the overall situation.Soil and water ecology is the holistic view of nature of seeing both macrocosm and microcosm,is the largest common divisor of various types of ecosystems on the earth and will effectively integrate all ecological processes related to human beings,animals and plants.Starting from the principle of soil and water ecology,the paper resolved that:①the essence of landscape,forest,field,lake,grass,sand and ice is soil and water ecology and;②the fundamental reason of the ecological and environmental crises of climate change,global warming and loss of biodiversity lies in the change and destruction of the earth’s soil and water ecology.The theory of soil and water ecology is a major scientific issue related to the fundamental and overall situation of the ecological environment,is the golden key to understand and solve contemporary ecological and environmental issues and is the common theoretical basis in the field of ecological environment.

Landscape Ecology:Coupling of Pattern,Process,and Scale

Landscape ecology provides new theoretical frameworks and methodologies for understanding complex ecological phenomena at multiple scales.Studies of landscape ecology focus on understanding the dynamics of eco-logical patterns and processes,and highlight the integration of multiple disciplines.In this paper,we discussed the problems and challenges that landscape ecology is currently facing,emphasizing the limitations of current methods used to describe dynamic landscape patterns and processes.We suggested that the focus should be on the integration of ground-based observation,mobile monitoring,transect survey,and remote-sensing monitoring,as well as improved coupling of experimental and model simulations.In addition,we outlined the research frontiers in landscape ecology,including scaling,integrated pattern and process modeling,and regional synthesis.Lastly,a brief review of pat-tern-process-scale coupling studies in China was provided.We concluded by pointing out that pattern-process-scale interactions,correlations between natural,economic,and social processes,and the coupling of human and natural systems will be major research areas in landscape ecology in the future.

Urban Green Space Planning Based on Computational Fluid Dynamics Model and Landscape Ecology Principle:A Case Study of Liaoyang City,Northeast China

As a result of environmental degradation,urban green space has become a key issue for urban sustainable development.This paper takes Liaoyang City in Northeast China as an example to develop green space planning using the computational fluid dynamics (CFD) model,landscape ecological principles and Geographical Information System (GIS).Based on the influencing factors of topography,building density and orientation,Shou Mountain,Longding Mountain and the Taizi River were selected as the urban ventilation paths to promote wind and oxygen circulation.Oxygen concentration around the green spaces gradually decreased with wind speed increase and wind direction change.There were obvious negative correlation relationships between the oxygen dispersion concentration and urban layout factors such as the building plot ratio and building density.Comparison with the field measurements found that there was significant correlation relationship between simulated oxygen concentration and field measurements (R 2=0.6415,p<0.001),moreover,simulation precision was higher than 92%,which indicated CFD model was effective for urban oxygen concentration simulation.Only less than 10% areas in Liaoyang City proper needed more green space urgently to improve oxygen concentration,mainly concentrated in Baitai and west Wensheng districts.Based on land-scape ecology principle,green space planning at different spatial scales were proposed to create a green space network system for Liaoyang City,including features such as green wedges,green belts and parks.Totally,about 2012 ha of green space need to be constructed as oxygen sources and ventilation paths.Compared with the current green space pattern,proposed green space planning could improve oxygen concentration obviously.The CFD model and research results in this paper could provide an effective way and theory support for sustainable development of urban green space.

Philosophical Thinking on Soil and Water Ecology

Any ecosystem is commonly composed of organism and environmental system. Vegetation is primary producer and key factor of biological system,while water and soil are leading factors of environmental system. How to conform to and use nature,protect the integrity and continuity of the ecosystem,play ecological service function of the system,protect and improve eco-environment needs grasping key factor of ecosystem or principal contradiction,namely water,soil and vegetation. Said from the source,all human activities are dealing with water,soil and vegetation,and continuously using and changing water,soil and vegetation for production of material goods and social economic construction,thereby affecting and changing natural environment. Main problems of eco-environment are induced by the interference and destruction on water,soil and vegetation by human activities. But human beings cannot manipulate and change natural phenomenon and rule,such as sunlight,diurnal variation and revolution of the earth. Soil and water ecology is the deepening and development of soil and water conservation view,and innovation and expansion of ecological science,and indicates a kind of ecological equilibrium relationship among soil,water and vegetation on the earth inter-associating,inter-promoting and inter-developing. Broadly speaking,soil and water ecology indicates the sum total of all relations among water,soil and vegetation in motion and evolution process. Cognition of soil and water ecology from the height of philosophy is conducive to further understanding important position and role of soil and water ecology theory in eco-environment,correctly recognizing position and relationship between man and nature,and clearly finding the key of current eco-environment problem and its future and direction,which could provide important theoretic support for maintaining earth's eco-environment and realizing sustainable development of mankind.

Progress of Chinese zooplankton ecology research in Prydz Bay, Antarctica

Zooplankton are considered an important trophic link between primary producers and higher trophic level species in the Southern Ocean ecosystem. Since 1989, when the Chinese Antarctic Zhongshan Station was built, zooplankton have regularly been sampled and investigated in Prydz Bay through oceanographic surveys of each Chinese National Antarctic Research Expedition. This review summarizes the main results from zooplankton ecology studies conducted in Prydz Bay by Chinese researchers. Major topics covered in this review are： （1） a description of the biology and ecology of Antarctic krill （Euphausia superba）, the key zooplankton species of the Southern Ocean ecosystem; （2） zooplankton community structure, including the horizontal distribution in the epipelagic region and vertical distribution between 0-1500 m; （3） feeding ecology of dominant species such as Antarctic krill, salps and copepods; （4） a short introduction to the molecular research; and （5） prospects for future research.

Development of Prataculture and Construction of Landscape City Based on the Rule of Water and Soil Ecology

This paper explored the necessity of protecting and using grasslands, grass mountains, grass slopes and grass shallows, the significance of prataculture for the economic transformation and upgrading and urbanization, feasibility, scientificity and naturalness of landscape city construction. It was proposed that pratacultural development, construction of landscape city, agricultural, water conservancy and planning should all follow the laws of water and soil ecology, the relationship between man, water, soil, vegetation and natural environment should be handled properly, ecological balance should be kept, so as to achieve the harmony between man and nature in addition to economic development.

Theory and Practice of Soil and Water Ecology

Author of this paper introduced the formation and development, main viewpoints, and framework of the theory of soil and water ecology, as well as the role and value of realizing the sustainable utilization of soil and water ecological resources, the sustainable maintenance of ecological environment, and the sustainable development of economy and society. The paper argued that in the current era, it is imperative to maintain the integrity and continuity of soil and water ecology and culture, emphasize the planning and construction of soil and water ecological infrastructure, and ensure the service functions of urban ecosystem, so as to realize the sustainable utilization of soil and water ecological resources, and the sustainable maintenance of ecological environment, and the sustainable development of economy and society.

Promoting the Construction of Beautiful and Rich China with the Theory of Soil and Water Ecology

Started from the problems and perplexities of ecological environment in China,the scientific principle and value of the theory of soil and water ecology are discussed. It is thought that the theory of soil and water ecology clarifies the complicated problems of ecological environment. Environmental pollution can be controlled,but it is only a matter of time and cost. Soil and water ecology is the root of ecological environment problems. The clean water and green mountain are destroyed,which cannot be restored. With the theory of soil and water ecology,the idea that clean water and green mountain are golden and silver mountains is read,as well as the way of turning clean water and green mountain into golden and silver mountains and its different impacts on eco-environment. The developed and underdeveloped areas should treat the idea that clean water and green mountain are golden and silver mountains. The application of the theory of soil and water ecology in soil and water conservation broadens the space of soil and water conservation,and it is necessary to establish a national commission for the conservation of soil and water ecology. The theory of soil and water ecology is the golden key to solve the problems of contemporary ecological environment and the theoretical basis for building a beautiful and rich China.

Forest landscape ecology and its applications in China

Landscape ecology is playing an increasingly important role in resources management and landuse planning in recent decades and attracting much attention from resource managers and scientists in China as well as in the world. Reviews of landscape ecology development in China have been well documented, whereas forest landscape ecology and its applications receive relatively fewer reviews. In this paper, we first present a brief review of the historical development and current advances of landscape ecology in China and then introduce the applications of landscape ecology to forest park designs, urban greenspace planning, ecological restoration, biodiversity conservation and forest eco-hydrology. Finally, the problems with the application of forest landscape ecology in China, such as inadequate synthesis and integration, lack of basic research on patterns and processes, basic data shortage and model usage problem are discussed on the basis of which we suggest a future direction of forest landscape ecology in China.

Diet and feeding ecology of invasive icefish Neosalanx taihuensis in Erhai Lake,a Chinese plateau mesoeutrophicated lake

A comprehensive study of the invasive icefish Neosalanx taihuensis feeding ecology in Erhai Lake was conducted from November 2009 to October 2010. Prey items in the guts of the icefish sampled varied significantly according to season. This finding suggests a relationship between fluctuations in available prey in the environment and selective feeding by icefish. N. taihuensis preferred large-sized zooplankton, such as Daphnia and calanoids. Additionally, the gut fullness values differed significantly （P〈0.001） among sampling times. To compare the values at different times, samples were taken over a 24 h period every 2 months for the entire year. The feeding activities of the fish were concentrated either in the morning （8：00） and/or at dusk （20：00）, except in September 2010. This finding can be explained primarily by the variation in optimum light intensity. Daily N. taihuensis zooplankton consumption varied significantly, both diurnally and among seasons. The daily consumption values ranged from 0.089 to 0.237 g （wet weight） per 100 g wet fish weight in temperatures between 11.50℃ and 24.68℃. This is the first report of diel feeding periodicity and daily food consumption of icefish in their invaded ecosystems.

Soil and Water Ecology as the Core Issue of Contemporary Biodiversity Conservation:A Case Study of the Population of Elk,an Endemic Species in China

From a new vision of the theory of soil and water ecology,it is discussed that soil and water ecology is the core issue of contemporary biodiversity protection.First,soil and water ecology constitutes the habitat for biological survival,and is the premise and foundation of biodiversity.Second,soil and water ecology is the material and energy source of biological survival and the prerequisite of biodiversity.Human beings are the beneficiaries and operators of soil and water ecology,which is related to the future and destiny of biodiversity on the earth.It should protect and restore the original,diverse,complete and clean soil and water ecology on the earth from three aspects of protecting pure natural soil and water ecology,protecting and restoring natural soil and water ecology,and building and regenerating artificial soil and water ecology,so as to fundamentally achieve biodiversity protection.

On Soil and Water,Soil and Water Ecology,and Soil and Water Ecological Conservation

On the basis of discussing the positions and functions of soil and water in terrestrial ecosystem,the concept of soil and water ecology is put forward.It is thought that the integral concept of inseparability between vegetation and soil,water is an important feature of soil and water ecology.Meanwhile,a new definition for soil and water ecological conservation is given,and it is divided into four types:ecological,natural,production and construction.At the height of soil and water ecology,it is an active,organic and holistic concept of soil and water conservation,and is deepening and development of the cognitive view on soil and water conservation to understand and control soil and water loss from the source and linkage of elements,which will make soil and water ecological conservation enter a new era.

Spatio-temporal Differentiation and Driving Factors of Industrial Ecology of Restricted Development Zone from Adaptive Perspective:A Case Study of Shandong,China

Based on the adaptive analysis paradigm,this paper constructs an evaluation index system and an evaluation model of the level of industrial ecology of a restricted development zone from the perspective of the industrial system and of the environmental system,and studies the spatial-temporal differentiation characteristics and the driving factors of the level of industrial ecology of the restricted development zone of the Shandong Province,China,by using a variety of measurement methods.The results show that:1)In the temporal dimension,the level of industrial ecology of the research area increased from 2005 to 2017,while in the regional dimension,it was higher in the eastern coastal areas,followed by the northwestern area and the southwestern area;2)In the spatial dimension,from 2005 to 2017 the level of industrial ecology of the research area had a clear spatial dependence,and the regional spatial agglomeration of the restricted development zones with similar industrial ecology levels become increasingly evident;3)On the whole,the industrial ecology level in the study area had a clear spatial differentiation pattern,as it was higher in the north and in the east and lower in the south and in the west.Moreover,its evolution model changed from a‘three-core driven model’to a‘spatial scattered mosaic distribution model’,and then to a‘single-core driven model’;4)Industrial ecology was positively correlated with economic development,foreign investment,science and technology,and negatively correlated with the government role,while industrial structure and environmental regulation failed to pass the statistical significance test.

Ecology,growth and management of black locust(Robinia pseudoacacia L.),a non-native species integrated into European forests

Black locust(Robinia pseudoacacia L.),a species native to the eastern North America,was introduced to Europe probably in 1601 and currently extends over2.3×10~6 ha.It has become naturalized in all sub-Mediterranean and temperate regions rivaling Populus spp.as the second most planted broadleaved tree species worldwide after Eucalyptus spp.This wide-spreading planting is because black locust is an important multipurpose species,producing wood,fodder,and a source of honey as well as bio-oil and biomass.It is also important for carbon sequestration,soil stabilization and re-vegetation of landfills,mining areas and wastelands,in biotherapy and landscaping.In Europe,black locust is drought tolerant so grows in areas with annual precipitation as low as 500-550 mm.It tolerates dry,nutrient poor soils but grows best on deep,nutrient-rich,well-drained soils.It is a fast-growing tree and the height,diameter and volume growth peak before the age of 20.It mostly regenerates vegetatively by root suckers under a simple coppice system,which is considered the most cost-effective management system.It also regenerates,but less frequently,by stool sprouts.Its early silviculture in production forests includes release cutting to promote root suckers rather than stool shoots,and cleaning-respacing to remove low-quality stems,reduce the number of shoots per stool,and adjust spacing between root suckers.In addition,early,moderate and frequent thinning as well as limited pruning are carried out focusing on crop trees.The species is regarded as invasive in several European countries and its range here is expected to expand under predicted climate changes.

Contribution of Study Bioecology of the Fauna Chamaerops humilis in the Region of Tlemcen （Algeria）

The region of Tlemcen is situated in the north-west of Algeria. The aridity of the climate had lead to the development of the matorral, a state of degradation of the Mediterranean, and the composed xerophytes plants such as doum and diss, had been found. Chamaerops humilis, xerophyte plant, with special morphologic and botanic character presents a resistance of these climatic. The authors have proposed study of fauna closly linked to this plant. A faunistic inventory was realized in the Mansourah area （region of Tlemcen）. Four stations have been described. Collecting sample was performed during June 2003-Mar. 2004, replying on sixteen （16） prelevements. The number of species were estimated of about 136, in which 111 are Arthropoda, the Entomofauna represented by 97 species and the other inventory are Arachnida by 8 species and Myriapoda by 6 species. 18 species are related to Gastropoda. The vertebrates are few. The importance of different groups＇ recolted on the Chamaerops humilis in the four stations is done particular to the insects. Analysis factorial correspondence （A.F.C） show different grouping of animal species.

The Present Situation and Development Research of Recreation Ecology

With the continuous development of society,the problem of the tourism also appears more outstanding.The article analyzed the relationship between ecotourism and recreation ecology on the basis of the understanding and researching,and put recreation ecology forward a deeper level of request.How to develop the tourism,including ecotourism,is the problem to be solved.Five research methods about recreation ecology were introduced,namely the field survey method,the positioning method,the ecological simulation method,the modern information technology method and the tourism evaluation and planning method,from the point of view of research methods to elaborate the present situation of recreation ecology at home and abroad.The relationship of recreation ecology and landscape ecology,landscape architecture,biological statistics and the potential were discussed at the end of the article.

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments