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Peer review report 2 on “Slope position influences vegetation-atmosphere interactions in a tropical montane cloud forest”
Agricultural and Forest Meteorology 217 (2016) 239
Contents lists available at ScienceDirect
Agricultural and Forest Meteorology journal homepage: www.elsevier.com/locate/agrformet
Peer Review Report
Peer review report 2 on “Slope position influences vegetation-atmosphere interactions in a tropical montane cloud forest”
Original Submission Recommendation Minor Revision Comments to Author Berry and colleagues present a study examining variability in sap flow velocity across a topographic gradient for dominant canopy species in a tropical mountain cloud forest. The study uses heat pulse sap flow velocity measurements and measurements of key environmental drivers. The authors find that, in general upslope trees exhibit stronger responses to environmental drivers, and that these responses vary between day and night, and clear and foggy conditions. The conclusion in thus that accounting for variable transpiration responses to environmental drivers associated with differences in topographic and environmental conditions will improve areal estimates of transpiration at the catchment scale. The methodology seems fine to me, and I think that this paper makes a nice contribution. The paper should be improved via a few fairly minor revisions before being considered further for publication. The introduction would benefit from a more explicit description of what we know about tree water dynamics in TMCFs. I’ve gathered from checking some of your references that leaf wetness and fog are associated with foliar water uptake, but you never come out and state this clearly. People who work in TMCF ecosystems probably understand what’s going on, but it is less clear for folks like myself who work in other systems. I also find myself wondering about what mechanisms and processes might be responsible for your results. Can foliar uptake act in a similar manner to stem recharge? etc. . . Some of this may fit better in the discussion section, but I think a more explicit description of what we know about plant water use in these systems would help make the paper more accessible, and this is important since it addresses interesting questions about topographic variation that are of broader interest. In general, the writing could be tightened up a bit, which would improve clarity of the manuscript. The discussion section in particular seems as if it may have been written in haste. There are some
DOI of published article: http://dx.doi.org/10.1016/j.agrformet.2016.02.012. http://dx.doi.org/10.1016/j.agrformet.2016.11.065 0168-1923/
cumbersome sentences with redundant word use that are clunky and unclear. Also, I think the discussion section would benefit from the addition of subsections. It has several distinct themes, so why not break it up a bit. I’m wondering if the variation in response of sap flow velocity across slope positions might change with time, or if there are lags in the responses? For example, as the dry season progressed would you expect to see a stronger coupling between sap flow velocity and environmental drivers at the low slope site? At longer time scales you might see responses to soil moisture, which most likely does not vary on short timescales like the other environmental drivers. Related, it would be nice to see soil moisture data presented in Table 2. Since you look at immediate responses of sap flow velocity to environmental drivers, this would be hard to test, and I’m not necessarily suggesting that you should. You do touch on soil moisture in the discussion, but it may be worth including some more discussion on this topic. Specific Comments L59: What are “These drivers” the previous sentence mentioned only water potential gradients, and plant anatomy traits. L77: By ‘these variables’ are you referring to environmental drivers? L78: Does ‘strong solar radiation’ mean high PAR, high incident SW, or large daily integrated values? L156: What year was the study conducted? L 194: Where is this in the canopy, what is the canopy height? L260 - 262: Was the May 26 - July 2 window the entire study period, or is there data from outside these time periods. Table 2 - Perhaps you could show soil moisture here as well. Figure 1 - It would be interesting to see a mean velocity for each slope position as well. Last, here is a good ref related to tree sample size and scaling: Mackay, D.S., Ewers, B.E., Loranty, M.M. and Kruger, E.L., 2010. On the representativeness of plot size and location for scaling transpiration from trees to a stand. Journal of Geophysical Research: Biogeosciences (2005-2012), 115(G2). Anonymous Available online 2 December 2016
Contents lists available at ScienceDirect
Agricultural and Forest Meteorology journal homepage: www.elsevier.com/locate/agrformet
Peer Review Report
Peer review report 2 on “Slope position influences vegetation-atmosphere interactions in a tropical montane cloud forest”
Original Submission Recommendation Minor Revision Comments to Author Berry and colleagues present a study examining variability in sap flow velocity across a topographic gradient for dominant canopy species in a tropical mountain cloud forest. The study uses heat pulse sap flow velocity measurements and measurements of key environmental drivers. The authors find that, in general upslope trees exhibit stronger responses to environmental drivers, and that these responses vary between day and night, and clear and foggy conditions. The conclusion in thus that accounting for variable transpiration responses to environmental drivers associated with differences in topographic and environmental conditions will improve areal estimates of transpiration at the catchment scale. The methodology seems fine to me, and I think that this paper makes a nice contribution. The paper should be improved via a few fairly minor revisions before being considered further for publication. The introduction would benefit from a more explicit description of what we know about tree water dynamics in TMCFs. I’ve gathered from checking some of your references that leaf wetness and fog are associated with foliar water uptake, but you never come out and state this clearly. People who work in TMCF ecosystems probably understand what’s going on, but it is less clear for folks like myself who work in other systems. I also find myself wondering about what mechanisms and processes might be responsible for your results. Can foliar uptake act in a similar manner to stem recharge? etc. . . Some of this may fit better in the discussion section, but I think a more explicit description of what we know about plant water use in these systems would help make the paper more accessible, and this is important since it addresses interesting questions about topographic variation that are of broader interest. In general, the writing could be tightened up a bit, which would improve clarity of the manuscript. The discussion section in particular seems as if it may have been written in haste. There are some
DOI of published article: http://dx.doi.org/10.1016/j.agrformet.2016.02.012. http://dx.doi.org/10.1016/j.agrformet.2016.11.065 0168-1923/
cumbersome sentences with redundant word use that are clunky and unclear. Also, I think the discussion section would benefit from the addition of subsections. It has several distinct themes, so why not break it up a bit. I’m wondering if the variation in response of sap flow velocity across slope positions might change with time, or if there are lags in the responses? For example, as the dry season progressed would you expect to see a stronger coupling between sap flow velocity and environmental drivers at the low slope site? At longer time scales you might see responses to soil moisture, which most likely does not vary on short timescales like the other environmental drivers. Related, it would be nice to see soil moisture data presented in Table 2. Since you look at immediate responses of sap flow velocity to environmental drivers, this would be hard to test, and I’m not necessarily suggesting that you should. You do touch on soil moisture in the discussion, but it may be worth including some more discussion on this topic. Specific Comments L59: What are “These drivers” the previous sentence mentioned only water potential gradients, and plant anatomy traits. L77: By ‘these variables’ are you referring to environmental drivers? L78: Does ‘strong solar radiation’ mean high PAR, high incident SW, or large daily integrated values? L156: What year was the study conducted? L 194: Where is this in the canopy, what is the canopy height? L260 - 262: Was the May 26 - July 2 window the entire study period, or is there data from outside these time periods. Table 2 - Perhaps you could show soil moisture here as well. Figure 1 - It would be interesting to see a mean velocity for each slope position as well. Last, here is a good ref related to tree sample size and scaling: Mackay, D.S., Ewers, B.E., Loranty, M.M. and Kruger, E.L., 2010. On the representativeness of plot size and location for scaling transpiration from trees to a stand. Journal of Geophysical Research: Biogeosciences (2005-2012), 115(G2). Anonymous Available online 2 December 2016