نتایج جستجو برای: forest dynamics

تعداد نتایج: 539268  

Journal: :Theoretical population biology 1998
H Lischke T J Löffler A Fischlin

Individual based, stochastic forest patch models have the potential to realistically describe forest dynamics. However, they are mathematically intransparent and need long computing times. We simplified such a forest patch model by aggregating the individual trees on many patches to height-structured tree populations with theoretical random dispersions over the whole simulated forest area. The ...

Journal: :Ecology letters 2007
Kyle S Van Houtan Stuart L Pimm John M Halley Richard O Bierregaard Thomas E Lovejoy

Many ecologists believe birds disappear from tropical forest fragments because they are poor dispersers. We test this idea using a spatially explicit capture data base from the Biological Dynamics of Forest Fragments Project near Manaus, Brazil. We measure bird movements directly, over relatively large scales of space and time, both before and after landscape fragmentation. We found that specie...

Journal: :محیط زیست طبیعی 0
حسین وارسته مرادی استادیار گروه محیط زیست، دانشکده شیلات و محیط زیست، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، ایران

population management of exploited species requires information on absolute density and abundance through reliable survey methods. the baseline information is further needed for population dynamics studies and determination of conservation status. the current population size of pheasant is totally unknown, because there is no official attempt to estimate population size in previous years. in th...

2002
I. KOZAK

Results of investigation of fir forest dynamics in the Bieszczady Mountains using a FORKOME (FORest KOzak MEnshutkin) model in response to climate changes are presented. The model was verified in field trials in 1998–2001 in a fir forest in forest district Procisne in the Bieszczady Mountains (Poland). Prediction of tree biomass and tree number was made for the next 600 years. The simulation de...

2012
V M RAVI KUMAR

Major focus has been devoted in the last three decades to administrative and economic aspects of colonial forest policies in south India, but scientific aspects received little attention. Consequently scientific dynamics of British forestry remained a less focused domain in the literature on colonial forest history. By examining the history of forest policies in south India this paper proposes ...

Journal: :آب و خاک 0
علی آزموده عطااله کاویان کریم سلیمانی قربان وهاب زاده

abstract land use change, especially natural ecosystems transformation, has high effects on soil physico-chemical as well as biological characteristics and also, has effect on runoff and soil erosion. analysis of runoff and soil erosion dynamics can be useful in improvement of management proposals and quantifying runoff and soil erosion changes. so, this research was carried out to investigate ...

2008
Yves Bergeron Pierre J.H. Richard Christopher Carcaillet Sylvie Gauthier Mike Flannigan

Because some consequences of fire resemble the effects of industrial forest harvesting, forest management is often considered as a disturbance having effects similar to those of natural disturbances. Although the analogy http://www.ecologyandsociety.org/vol2/iss2/art6/ (1 of 11) [9/5/2008 10:08:21 AM] Conservation Ecology: Variability in fire frequency and forest composition i...'s southeastern...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه گیلان - دانشکده علوم انسانی 1392

this study investigated how group formation method, namely student-selected vs. teacher-assigned, influences the results of the community model of teaching creative writing; i.e., group dynamics and group outcome (the quality of performance). the study adopted an experimental comparison group and microgenetic research design to observe the change process over a relatively short period of time. ...

2015
Maria O. Hunter Michael Keller Douglas Morton Bruce Cook Michael Lefsky Mark Ducey Scott Saleska Raimundo Cosme de Oliveira Juliana Schietti Runguo Zang

Gap phase dynamics are the dominant mode of forest turnover in tropical forests. However, gap processes are infrequently studied at the landscape scale. Airborne lidar data offer detailed information on three-dimensional forest structure, providing a means to characterize fine-scale (1 m) processes in tropical forests over large areas. Lidar-based estimates of forest structure (top down) differ...

2012
Zhen Sui Zhaofei Fan Xingang Fan

Forests of the coastal plain region of the southern United States are unique in their productivity, biodiversity, and economic value. However, natural and anthropogenic disturbances may trigger forest age structure and spatial distribution variation. Detecting and predicting tree species distribution patterns can help to understand the dynamics of disturbances in order to develop adequate fores...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید