• Wei-Sheng Zeng added an answer:
    Can I estimate a simultaneous equation system containing different observations?

    I want to develop a biomass model system including aboveground biomass model, belowground biomass model and stem, branch and foliage biomass models. Because the observations are different, so I deveolped two equation systems for aboveground biomass and belowground biomass respectively. But somebody suggest that we can use dummy variables for fitting both equation systems simultaneously. Could anyone give me detailed suggestion to solve the problem using dummy variables? Thank you.

    Wei-Sheng Zeng

    Dear Jamal, thank you. I will read the references you suggested at first.

  • Taqiyeddine Bensouilah added an answer:
    Is there any index used to determine the diversity of wildlife in plantation area?

    I am not really sure about and how to used the index and determine the wildlife or insects in natural forests or plantation areas.

    Taqiyeddine Bensouilah

    Dear Yonny,

    You can try Shannon diversity index


  • James Aaron Hogan added an answer:
    Has anyone information or articles about the destruction of the forests of the world over the past decade ?

    We are investigating the destruction of the forest
    and factors contributing to the degradation of Hyrcanian forests in Iran.

    James Aaron Hogan

    Science 7 December 2012:
    Vol. 338 no. 6112 pp. 1305-1306
    DOI: 10.1126/science.1231070
    Global Decline in Large Old Trees
    David B. Lindenmayer1, William F. Laurance2, Jerry F. Franklin3

  • Juan Cabris added an answer:
    Are there any case studies where Integrated Pest management has been implemented in forestry?

    Any references would be appreciated

    Juan Cabris

    You are very welcome, Phillip. I regret that everything I had at the moment was in Spanish. I should be glad if it was useful. Best regards, Juan

  • Bernhard Meier zu Biesen added an answer:
    Can vertical farming be used in tropical forests as an alternative to conventional (horizontal) farming?

    Farming is considered to be the first cause of deforestation in the tropics. Our research team is currently looking for farming solutions that may replace conventional small- and large-scale farming in Brazilian rainforests. Our current assumption is that vertical farming, mainly conceived for urban areas, may be an alternative that has a much smaller impact on the forest because of their small footprint and diffuse spatial distribution (vertical farms scattered around the forest, instead of being clustered), thus drastically reducing deforestation. We are confronted with the following questions:

    - Is there any knowledge on how productive vertical farms are in tropical forests?

    - What kind of new problems would vertical farms bring for farmers?

    - Can current farming products be stacked vertically?

    - Can vertical farming be realised with low-tech solutions?

    We would highly appreciate any feedback on these questions.

    Bernhard Meier zu Biesen

    These orientations from my side:

    1. Question has to be answered simply by "No", but VF can be --- in probably all agro-eco-systems --- a fantastic and trial-worthy supplement to conv. farming, also in view of the future high needs of food, industrial raw-materials, crops of biogas-units, etc..

    2. I have tested this year how much I can produce in a vertical-setting on 1 square-meter; it is breath-taking, but not easily possible on large land-areas.

    3. I suggest to focus on a few very practical and pragmatic part-options and test further (the 3,000 or so potential crops offer a wide spectrum of options):

    -----a. Growing crops like zucchini or eggplant in mixture with maize-like plants. These offer an enormous yield-intensity.

    -----b. Searching / checking / using the benefits of allelopathy-effects of plants in perma-culture-settings for VF.

    -----c. Applying drip-irrigation-systems for easy irrigation and little water-consumption.

    -----d. Priorizing climbing / creaping plants and letting them go-up on trees, stakes, palls, etc.

    -----e. Checking the option of a potatoe-box principle: start growing on ground, then filling gradually continuously in the 1 or 2 or 3 or10 cubic-meter-box; after end of growth (period) just tearing the soil apart and picking the potaties. Many tuber-crops might offer this option for VF. The famous potatoe-box is usually 1 cub.m.

    4. The systems and chances for VF depend largely on the a) technical material for erecting / constructing durable vertical levels. Best is looking for some sec.hand-material from construction-sites or factories, etc. b) irrigation demands the cheap systems of drip / trickle irrigation in case the tropical forest is not rainy enough. c) Mulching, mixed crop-stands, perma-culture or systems like that need to ensure highest yields per squaremeter.

    5. With adequate agronomical creativity and good www-search you could even find solutions for a "Yes" to the question.

  • Abhishek Raj added an answer:
    How can we measure bulk density of a different types of forest soil?

    Thanks in advance for your replies.

    Abhishek Raj

    see attached articles. 

    + 1 more attachment

  • Neal Ferris added an answer:
    Does anybody know any other central tree for the European colonial empires?

    Acajou (Khaya sp.), okume (Aucoumea klaineana) and teka (Tectona grandis) were very important for the French, German, Spanish and British  forestry colonial economy. Does anybody know any other central tree for the European colonial empires?

    Neal Ferris

    In a different vein but perhaps of interest, the eastern white pine (Pinus strobus) of the northeast of North America was a key resource for shipbuilding in particular (very tall and straight trees ideal for masts, and very strong but light material). It was key for the British in the later 17th and 18th centuries, since otherwise they were in competition for supplies elsewhere in the world. Surveys of forests led to trees being marked as King's property, often ignored by colonialists, and was another tension leading up to the American Revolution.

    Cheers, Neal

  • Fabrice Dagrain added an answer:
    Can you comment on the indirect estimation of wood density and its importance in forestry?
    See above
    Fabrice Dagrain

    Dear Uthappa,

    I confirm the information given by Vladimirs. I'm using micro-drilling on wood. Based on applied load on bit and torque while drilling, it is possible to assess some properties of the wood such as density.

    Best regards,


  • Abhishek Raj added an answer:
    Is it possible that trees of same species have different response to light conditions at different ages?

    For example SLA (Specific Leaf Area) and biomass allocated to leaves have different responses to light condition at different ages.
    In other hand, in smaller trees, SLA decreased by increasing light availability but in bigger ones, it increased by increasing light availability.

    Thanks for your helps

    Abhishek Raj

    Yes, the requirement of light varies with species, and in the same species, at the various stages of its development. That why on the basis of their tolerance, they are classified into light demanders, shade bearers and shade demanders.  In shade demanders is covers trees those require light in early stages (seedling) but after a certain stage is demanded for shade for tolerance.  for examples, Fir and Taxus species in moist temperate forest, Oak in subtropical forest, Kusum, Jamun in tropical moist deciduous forest and Mesua ferrea in tropical wet evergreen forest  shows that type of light requirement as per different growth stages in same species.

    In actual practice, the classification becomes complicated due to varying responses to light by species not only in different conditions  but also at various stages of their development. For example, sal is able to persist under moderate shade but its best development is obtained by admission of complete overhead light, right from earlier stage, though it requires partial shade in the beginning.  

  • Tia Hayes added an answer:
    Is there literature on palm tree distribution through primary and secondary forest in Ecuador?

    I looked at number of juveniles, nearest adult, height of each palm, species of palm, amount of light coming through the canapy, humidity and temperature any help would be great 

    Tia Hayes

    Thank you guys ill give them all a read through your a great help :)

    Kind Regards 


  • Omid Fathizadeh added an answer:
    How to measure stemflow of coppice stands such as Quercus sp?

    As we know, coppice species like Quercus sp create several stems per tree making them somewhat hard to estimate their hydrological processes accurately. Does anybody have any ideas as to how to do it?

    Take a look at attached file to see a coppice tree.

    Omid Fathizadeh

    Hi dear Ugur,

    Yes, I know a little about it, but, it needs some requirements/instruments that you are not able easily access them here.


  • Carl W. Mize added an answer:
    How far apart do forest inventory plots need to be apart to be considered a systematic sample?

    I am helping foresters in the tropical forests of the Yucatan Peninsula with the analysis of inventory data.  They use strip plots but often have relatively few in an inventory so their t value for a confidence interval is large and the confidence interval for volume is large also. They are considering changing to systematically arranged fixed area plots and would like to keep them relatively close. That creates the question - how close?

    Carl W. Mize

    thanks and i agree with you.  unfortunately, the people tend to take a 1 or 2 percent cruise by tradition.  it is often too small to achieve required precision but they accept that for economic reasons.  also, random location in a tropical forest is much more work than in temperate forests.  they usually do strip plots as they can measure trees while moving through the forest.  it is more efficient.  though they have been receptive to the idea of taking larger plots at fixed distances - systematic sampling along lines.

  • Abhishek Raj added an answer:
    What is a suitable method to determine rate of combustion of tropical peat?

    to compare tropical peat by depth

    Abhishek Raj

    Hi Dayang

    See an article entitled "Combustion and thermal characteristics of peat fire in tropical peatland in Central Kalimantan, Indonesia by Aswin USUP, Yoshihiro HASHIMOTO, Hidenori TAKAHASHI and Hiroshi HAYASAKA (link: https://www.jstage.jst.go.jp/article/tropics/14/1/14_1_1/_article)

    Also see an attached article for more valuable information.

    + 1 more attachment

  • Mugunthan Perumal added an answer:
    What is the best transplanting period for Shorea macrophylla seedlings after nursery stage to the field?

    Reforestation, Soil Fertility, Ecology 

    Mugunthan Perumal

    Dear Afi, could you mind to share with me any papers/journals related to the suitability of seedlings to be planted after nursery stage? The one you have mentioned earlier in Kalimantan. Many thanks.  

  • Rabiou Habou added an answer:
    Can we use c-band data for estimation of above ground biomass in woodlands?

    We know l & p bands data are better than c-band data for estimation of AGB, But l & p bands data not available for woodlands in Iran.

    Rabiou Habou

    it is possible if you can utlise lazer range finder to estimate the distance between the individual and a point on the azimuth direction in the observation band. This way you can increase the size of your sample and eventuelement reliability of your analysis.

  • Sean C Thomas added an answer:
    Which criteria should be considered when buying a fish-eye lens for the measurement of leaf area index (LAI)?

    I have a planning on buying a fish-eye lens, and therefore, I need to know some criteria before buying. Most Regards, Moein

    Sean C Thomas

    An additional critical point is that the fisheye lens should be equalangular (a displacement along the image radii at any distance from the center to the edge should correspond to the constant angular displacement).  Some analysis software will allow you to adjust for non-equalangular lenses, but mostly this property is assumed.

  • Md. Siddiqur Rahman added an answer:
    How can the contribution of the forestry sector of any country be measured towards GDP calculation accurately?

    Forestry sector contributing toward national GDP has always been underestimated in the tropics due to many reasons. Ranging from environmental to educational, and widening between infrastructural and methodological approaches adopted; how best forest assests and liabilities could be accounted using GAAP (Generally Accepted Accounting Principles)?

    Md. Siddiqur Rahman

    that's what I was talking about...

  • Jean O'Dwyer added an answer:
    What is the best Life Cycle Assessment software in terms of cost:benefit?

    I am involved in a Forestry themed project and am assessing cascade use of harvested wood products and would like to employ LCA (though it is not the whole focus). However, the software is quite expensive for the big names i.e. SimaPro, GaBi, etc.

    Has anyone used OpenLCA? How does this compare to the paid platforms in terms of ease of use, accuracy, defensibly etc. 

    Any help would be greatly appreciated.

    Jean O'Dwyer

    Thank you all for your valuable insight. You have all been a great help.

  • Xiping Zhao added an answer:
    Which statistical analysis should I use to analyse my data?

    I want to compare Specific Leaf Area (SLA), Leaf Area Index (LAI) and biomass allocation of different tree components in different light condition (light gradient) for three species. I have three light level and also have the amount of light (%) for each tree individual. There are three replication for each light level and there are three trees in each replication. I want to know the impact of light and species on my above variables. Moreover, trees are not the same size and size affects the results. I want size to be ignored. only impact of the light and species.

    Thanks in advanced

    Xiping Zhao

    hi, Ardalan.The size affects the results. So,you can ignore that. I think  You can use a mixed effects model to analyze your data with tree size being a covariant.

  • Abhishek Raj added an answer:
    Which method on gene transfer on forest species is better?


    For improve the velocity of the plant growth, on arid forest species, which biblography o references are recommending? Regards

    Abhishek Raj

     I agree with Nicola sir. It is depending on type of species you require for studies of  method of gene transfer.

    For detail and more information u can look "Gene Transfer in Forest Trees" by M. R. Ahuja in Genetic Manipulation of Woody Plants, Basic Life Sciences Volume 44, 1988, pp 25-41. (link: http://link.springer.com/chapter/10.1007%2F978-1-4613-1661-9_2)


    Abhishek Raj

    + 1 more attachment

  • Abhishek Raj added an answer:
    What are the opportunities and challenges in adopting ecosystem-based approach for managing degraded ecosystems in semiarid landscapes (Ghana)?

    Role of local knowledge practices.

    Climate change and variability impacts.

    Abhishek Raj

    Hii Yaw Agyeman

    You may look a case study on "Adaptation Learning Programme in Ghana: Women take lead in tackling climate change" in CareClimateChange under Climate change information centre. (link: http://careclimatechange.org/case-studies/adaptation-learning-programme-ghana-women-lead/)

    Also see an attached file for more valuable information

    + 2 more attachments

  • Neil Andrew White added an answer:
    Is it important to carry out a research to determine fruit yield of Mangos? Interpret results to needy communities on yield of fruit trees planted.

    Departmental Orchards in Northern Namibia.

    Determining fruit yield of Mangos.

    Neil Andrew White

    This is important in all societies. Growers need access to the affect of management on fruit yield regardless of their socio-economic status. Muhammad's answer is interesting to me as we are investigating a range of "radical" approaches to increasing yield per ha in mango, macadamia and avocado, including training, high density and dwarfing rootstocks.

  • Peter Salonius added an answer:
    To integrate or to segregate: what are the best approaches for the conservation of forest biodiversity?

    In Europe, but also in other parts of the world, there are two different main approaches for forest biodiversity conservation on a larger scale (landscape, regional, national scale). The segregative approach separates large areas for nature reserves without any management from other areas with intensive forest management for economic purposes. The integrative approach tries to combine nature conservation and economic management by including the provision of e.g. structural heterogeneity, species mixtures and DWD in a more extensive, so-called 'close-to-nature' forestry.

    I wonder if there are studies and scientific results regarding the efficiency and cost-benefit ratios of both approaches in comparision. I would be glad if you could provide me with any information on this for any part of the world.

    There is a nice publication of the European Forest Institute (EFI) providing more insights in the integrative approach (see link).

    Thanks a lot in advance.

    Best regards,

    Peter Salonius

    Subject: Subsidy alternatives to change forest management 
     you may be interested to read:
    'Shifting regeneration subsidies - A route to saving money and restoring temperate forest
    starting on Page 5 and continuing on Page 7........ at:

    Peter Salonius

  • Christoph Leibing added an answer:
    In short rotation forestry, which density per hectare provides the greatest amount of biomass in 5 years for poplar sp.?

    For short rotation forestry, which density per hectare provides the greatest amount of biomass in 5 years for poplar sp.?

    Christoph Leibing


    modern 5 a rotation SRC in Europe with max yield in bdt/ha is 1660 trees per ha, usually in 3x2m spacing. The genotypes used are usually P. euroamericana clones. Would be great to receive a copy of your article once you are published lulian.



  • Emily Gilbert added an answer:
    Can a strip sampling method be as effective as line transect sampling for tree inventory?

    I wanted to know if a strip sampling method can be as effective as line transect sampling for tree inventory especially in representing a 0.1 ha of a forest area.

    Emily Gilbert

  • Farhad Khorsandi added an answer:
    Why is acacia sp. more popular for paper production than kenaf sp?
    As I made some revision on this species, kenaf is quite a multipurpose species. So I wonder why this species is not really well known among the people.
    Farhad Khorsandi

    Excellent answers by Frank and Tarig. I may also add that in general Acacia species require less water, which is an important factor in dry arid regions.

  • Iulian Danila added an answer:
    Any suggestions on seedling, cuttings or rods for short rotation forestry (SRF)?

    what is the most productive type of material for reproduction in biomass production? generally is used for poplar SRF - cuttings, seedlings and sits (rods). Thanks.

    Iulian Danila

    in Romania we have some different results about all type of reproduction material, so for different density (1333 - 2667 trees/ha), and different cycle we obtained that seedlings and rods (sits) are higher than cuttings of Max 4.

  • Megan Foley added an answer:
    How to estimate Leaf Area Index/Canopy Area Index (LAI/CAI) of individial trees by using of hemispherical photos?

    Hello all,

    I am about to estimate leaf area index (in the leafed period) and canopy area index (in the leafless period) of some sparse oak forest stands. Since these forest are very sparse in density, we should consider, first, some individual trees to estimate and generalize these individual estimates to whole stands then. So, we need to estimate LAI and CAI of single trees. Meanwhile, change detection of aforementioned indexes in various phenological stages is the reason for using hemispherical photos.

    Best wishes,


    Megan Foley

    Here's a paper you might find useful: "Validation of LAI and FPAR products" (http://data.auscover.org.au/xwiki/bin/view/Good+Practice+Handbook/LAIFPARValidation?xpage=office&attachment=LAIandFPAR_Validation_For_AusCover_Greenbook_v13.docx)

    And here's one of the instruments discussed that is good for measuring LAI in the field: http://www.cid-inc.com/products/leaf-area-lai/plant-canopy-imager 

    Hope that helps!

  • Sean C Thomas added an answer:
    What is a standard method to calculate carbon sequestration by trees?

    We have counted trees for carbon sequestration of our university. I wish to know the standard method to calculate carbon sequestered by these trees.

    Sean C Thomas

    As mentioned the most common approach for forest C inventory is to utilize allometric equations for biomass, and then to assume that woody tissue is 50% carbon.  This latter assumption is, however, incorrect - see publications below for guidance.

    • Source
      [Show abstract] [Hide abstract]
      ABSTRACT: Accurate knowledge of carbon (C) content in live wood is essential for quantifying tropical forest C stocks, yet generic assumptions (such as biomass consisting of 50% carbon on a weight/weight basis) remain widely used despite being supported by little chemical analysis. Empirical data from stem cores of 59 Panamanian rainforest tree species demonstrate that wood C content is highly variable among co-occurring species, with an average (47.4±2.51% S.D.) significantly lower than widely assumed values. Prior published values have neglected to account for volatile C content of tropical woods. By comparing freeze- and oven-dried wood samples, we show that volatile C is non-negligible, and excluding the volatile fraction underestimates wood C content by 2.48±1.28% (S.D.) on average. Wood C content varied substantially among species (from 41.9-51.6%), but was neither strongly phylogenetically conserved, nor correlated to ecological (i.e. wood density, maximum tree height) or demographic traits (i.e. relative growth rate, mortality rate). Overall, assuming generic C fractions in tropical wood overestimates forest C stocks by ∼3.3-5.3%, a non-trivial margin of error leading to overestimates of 4.1-6.8 Mg C ha(-1) in a 50-ha forest dynamics plot on Barro Colorado Island, Panama. In addition to addressing other sources of error in tropical forest C accounting, such as uncertainties in allometric models and belowground biomass, compilation and use of species-specific C fractions for tropical tree species would substantially improve both local and global estimates of terrestrial C stocks and fluxes.
      PLoS ONE 08/2011; 6(8):e23533. DOI:10.1371/journal.pone.0023533

    + 1 more attachment

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