1、Dear Editors and Reviewers,Thank you for your letter and comments on our manuscript titled “Temporal variability in soil moisture after thinning in semi-arid Picea crassifolia plantations in northwestern China” (FORECO_2017_459). These comments helped us improve our manuscript, and provided importan
2、t guidance for future research. We have addressed the editors and the reviewers comments to the best of our abilities, and revised text to meet the Forest Ecology and Management style requirements. We hope this meets your requirements for a publication.We marked the revised portions in red and highl
3、ighted them yellow in the manuscript. The main comments and our specific responses are detailed below:Editor:Please explain how the results in this paper are significantly different from those in Zhu, X., He, Z.B., Du, J., Yang, J.J., Chen, L.F., 2015. Effects of thinning on the soil moisture of the
4、 Picea crassifolia plantation in Qilian Mountains. Forest Research. 28, 5560.) Response: We apologize for our earlier lack of clarity about the differences between our study and those in “Zhu, X., He, Z.B., Du, J., Yang, J.J., Chen, L.F., 2015. Effects of thinning on the soil moisture of the Picea c
5、rassifolia plantation in Qilian Mountains. Forest Research. 28, 5560” (named “previous article” below). Specifically, we found three main differences in the temporal variability and hydrological responses of soil moisture between our study and the “previous article”. First, the scope of data analysi
6、s and use were different: The “previous article” just applied the one growing season data (from June 28th to October 25th 2013) from the natural forest and the plantations with no thinning and thinned in 20% intensity. In addition, the “previous article” also has not considered the effect of 40% thi
7、nning on the soil moisture of the Picea crassifolia plantation. However, in the present study, we applied four years data (from June 27th 2012 to October 30th 2015 in HD and NF; from January 1th 2014 to October 29th 2015 in MD and LD) from the natural forest and the plantations with no thinning, thi
8、nned in 20%, and thinned in 40% intensity to analysis the temporal variability and hydrological responses of soil moisture in semi-arid Picea crassifolia plantations in northwestern China.Second, the content of the research was different: The “previous article” only considered the spatial and tempor
9、al dynamic changes of soil moisture, but did not involve the inter-annual, and seasonal dynamic changes of the soil moisture. In the present study, however, not only did we considered the effects of thinning on the spatial and temporal dynamic changes, the inter-annual changes, and seasonal dynamic
10、changes of the soil moisture; but we also considered the changes in soil hydrological response after thinning. Our goals were to understand the changes in soil hydrological response and soil moisture dynamics, and to determine whether thinning management can effectively improve the state of soil moi
11、sture in the subalpine Picea crassifolia plantations in the Qilian Mountains.Third, the research purpose and the result were also different: The mainly purpose of the “previous article” was to preliminary explore the thinning on the plantation forest soil moisture, and they found that the intermedia
12、te thinning can significantly increase soil moisture content at the depth of 60 cm. However, they didnt point out that which or what the thinning intensity or plantation density can be benefit to sustainability of planted forests in these water-limited regions. In this study, not only we did confirm
13、ed that the intermediate thinning can significantly increase soil moisture content at the deep soil layer, but we also found that high planting density was the main cause of severe soil moisture deficits in the long-term, and it could be mitigated by 20 - 40% thinning (3139 trees ha-1). In addition,
14、 by investigating the effect of thinning on the soil hydrological response, we found that soil hydrological response may be temporarily modified by thinning according to changes in canopy structure, precipitation properties, and antecedent soil moisture conditions. Soil moisture in natural forest ra
15、pidly infiltrated into deep soil, which greatly improved the efficiency of precipitation use. Thinning significantly increased the capacity for soil infiltration, and moderate thinning intensity may be conducive to deep soil-water recharge. Further, according to the global circulation prediction mod
16、els and trend analysis results and weather patterns, deep VSWC may increase if precipitation patterns shift to produce larger but less frequent rainfall events during the growing season, and this change will benefit growth of the vegetation planted at higher density in this semi-arid region.Reviewer
17、 1I found the topic very interesting. The scientific (experimental) set-up is valid and the data is presented clearly, and analyzed in detail. My detailed comments are all in the attached pdf-file.Response: Thank you for your encouraging remarks and valuable comments. We corrected our text according
18、 to your comments submitted in the attached pdf-file. Our responses to your comments are as follows:Comments in attached pdf-file1. Keywords: maybe re-consider “Rainfall”Response: We fully agree that it is necessary to re-consider “Rainfall” in the Keywords section. In addition, the statement of “Ra
19、infall” was corrected as “Soil hydrological response” (L31). 2. Ln. 37: Expand, i.e. why are these specific regions water-limited.Response: We apologize for our earlier lack of clarity. To increase clarity, we have re-written this sentence accordingly, and we have corrected “Grassland afforestation
20、is critical in efforts to prevent wide-spread land degradation in arid and semi-arid regions of China (Chen et al., 2008a; Yang et al., 2014). However, sustainability of planted forests is severely limited by soil moisture conditions. Soil moisture is fundamental to sustainability in water-limited e
21、cosystems (Newman et al., 2006; Yang et al., 2014).” as “Grassland afforestation is critical in efforts to prevent wide-spread land degradation in arid and semi-arid regions of China (Chen et al., 2008a; Yang et al., 2014), where rainfall is the main source of soil moisture, and where many vegetatio
22、n restoration projects were implemented (Li, 2004). However, soil moisture is the most crucial factor to sustainability of planted forests in these water-limited ecosystems (Newman et al., 2006; Yang et al., 2014). (L35-40)”.3. Ln. 47: What is meant by “statistical moments of soil moisture, such as
23、mean and variance”?Response: It is meant that changes to canopy structure due to large-scale clearings or intermediate disturbance events may lead to changes in the mean and the variance of the soil moisture. We amended our text to clarify, and now it reads: “Changes to forest canopy structure due t
24、o large-scale harvesting may lead to changes in soil properties, residual tree growth, and the mean and the variance of the soil moisture (Chen et al., 1993; Olchev et al., 2009; He et al., 2013; Kaarakka et al., 2014).” (L48-51). 4. Ln. 60: add “ecosystems” (instead of cosystem)Response: The statem
25、ent of “cosystem” was corrected as “ecosystems” (L62).5. Ln. 68: change “determining” to “affecting”Response: The statement of “determining” was corrected as “affecting” (L71).6. Ln. 71: Expand this sentence a bit. Growing season where? At the studied region/area?Response: To increase clarity, we ha
26、ve re-written this sentence accordingly (L71-75). And our studied region/area is also experiencing this precipitation patterns, with larger but less frequent rainfall events during the growing season, and more frequent extreme hydrological events.7. Ln. 7480: Heisler-White, He et al. and Sun et al.
27、showed where, in what type of ecosystem, how does it relate to the studied one, i.e. elaborate more on how these studies relate to the current one.Response: That was an excellent suggestion, and we have made revisions according to your comments (L78-80, L83, L85-86). The study of Heisler-White et al
28、. (2008) provides a background knowledge of the supply of the precipitation on soil profile. The studies of He et al. (2012) and Sun et al. (2015) investigated the soil moisture dynamics of typical ecosystems (forestland, shrubland, grassland, and meadows) in response to precipitation, which can pro
29、vide a reference for our research.提供背景知识，了解降水对土壤的补给情况；He et al. and Sun et al.的研究研究了祁连山天然植被（林地、草地和灌丛）的土壤水分情况，是本文章研究的基础。The response of soil moisture to rainfall event size in subalpine grassland and meadows in a semi-arid mountain range: A case study in northwestern Chinas Qilian MountainsSun, F., L
30、, Y., Wang, J., Hu, J., Fu, B., 2015. Soil moisture dynamics of typical ecosystems in response to precipitation: A monitoring-based analysis of hydrological service in the Qilian Mountains. Catena 129, 63-75.8. Ln. 98: ponderosa PonderosaResponse: The statement of “ponderosa” was corrected as “Ponde
31、rosa” (L97).9. Ln. 118121: what is meant by “Tianbao”. Re-phrase this sentence, not sure what is meant by “returning the grain areas.” Refers to shift from agriculture to forestry?Response: Thank you for your valuable suggestions. We amended our text to clarify, and now it reads: “In recent decades,
32、 with the implementation of projects National Forest Conservation Program, “Grain for Green” program, and others and others, the area of planted vegetation in the Qilian Mountains has increased significantly (Li, 2004), and many semi-arid grasslands were converted to Picea crassifolia plantation for
33、ests (He et al., 2012).” (L128-132). 10. Ln. 124: Remove “growth efficiency”Response: The “growth efficiency” was removed (L134).11. Ln. 125: What is “weak stability” in this context soil moisture or something else?Response: We were happy to clarify the idea of a “weak stability of the ecosystem”, w
34、hich meant that the stability of the whole ecological system will show a decreasing trend with vegetation succession. To increase the validity of this point, we included literature sources that related to the stability of the ecosystem (Yue and Ma, 1991; Sankaran and McNaughton, 1999; Jiang et al.,
35、2002), and the bases on which stability was evaluated: (1) suitability for local environmental conditions, (2) the resistance to and the ability to recover from an external disturbance, (3) the ability of self-renewal and normal development, and (4) having a relatively stable population structure. 1
36、2. Ln. 126: Replace: “enhancement” “Improving the stability of the system”Response: The statement of “Enhancement of the stability in this system” was corrected as “Improving the stability of the system” (L136).13. Ln. 163: What is meant by “limited number of Larix” maybe add a stem density estimate
37、?Response: Thank you for your valuable suggestions. We added a stem density to clarify, and now it reads: “The vast, recently afforested areas had a high stand density around 4500 trees ha-1, and contained a limited number of Larix principis-rupprechtii Mayr trees (around 210 trees ha-1).” (L172-174
38、).14. Ln. 165: Remove “management”Response: The “management” was removed (L175).15. Ln. 166167: last sentence of the paragraph needs re-phrasing The thinning aimed to remove poor-growing trees as well those lacking vigor. What is meant by “fish-scale pit”, if this a regional term, define it. Does de
39、nsity in this context refer to stand density (i.e. to the density of the trees in a given area, in the pit)?Response: That was an excellent suggestion, and we have made revisions according to your comments (L167-177). The “fish-scale pit” in this study is a regional term and meant that “the pit of t
40、he plant trees”. In addition, the density in this context refer to stand density of the trees in a given area.16. Ln. 169: Rephrase. Maybe something like: “In early August 2013, a survey was carried out in the P. crassifolia plantation and in the nearby/adjacent natural P. crassifolia stand, which a
41、t the time of sampling were 31 and 41 years, respectively. Selected stands had similar site conditions.”Response: That was an excellent suggestion, and we have made revisions according to your comments (L182-185).17. Ln. 176177: Remove “except for the gathering of wild mushrooms between July and Aug
42、ust”Response: The “except for the gathering of wild mushrooms between July and August” was removed (L190).18. Ln. 198: Change to “a soil pit with the dimensions of”Response: The statement of “a soil pit with a dimensions of” was corrected as “a soil pit with the dimensions of” (L210).19. Ln. 199: Ch
43、ange 5 “five”Response: the statements of “5” was corrected as “five” (L212).20. Ln. 204205: What is meant by “the accepted range of soil temperature change”?( -40 to +60 C) temperature change in the soil or where? If in the soil, why such extreme numbers?Response: 这个只是仪器的测定范围，研究区土壤温度在什么什么范围（各个图层的都加加
44、上），所以用该仪器可以保证所测区域温度准确。21. Ln. 206: Remove “nearly-original”Response: The “nearly-original” was removed (L?).22. Ln. 212: Why was this data (20142015) not available? Maybe add an explanation.Response: The 80-cm data from the NF stand were not available for the 2014 and 2015 growing season due to the
45、volumetric water content and temperature ECH2O sensor at this layer was damaged. And we added an explanation at the line of L225-227.23. Ln. 214: Equation equationsResponse: The statement of “equation” was corrected as “equations” (L229).24. Ln. 192: Add “Total nitrogen (Ntot)” use that for total ni
46、trogen rather than “TN” (Ln. 268)Response: The statement of “total nitrogen” was corrected as “Total nitrogen (Ntot)”, and we use “Ntot” rather than “TN” in the following parts (L205).25. Ln. 268: Rephrase so that the reader understands that the SOC and Ntot varied with thinning intensity maybe .” s
47、oil depths tended to decrease with increased thinning intensity, while soil bulk density tended to increase.”Response: Thank you for your valuable suggestions. We amended our text to clarify, and now it reads: “Generally, SOC and Ntot in all sampled soil depths tended to decrease with increased thin
48、ning intensity, while soil bulk density tended to increase” (MS, L283-284). 26. Ln. 273274: Rephrase so that there will be less repetition.Response: We have re-written this part according to the Reviewers suggestion (L270-281).这句感觉没有重复。27. Ln. 287: Considered rephrasing “improving the utilization efficiency of precipitation”. Efficiency of the soil, stand?Response: thus improving the utilization efficiency of precipitation for soil.28. Ln. 334336: Here, the data is well presented, sums the results for the reader (for VSWC)Response: 除了10 cm外，NF在其他各个图层土壤水分最高。Soil moisture conten
