**5. Conclusions**

In this study, we explored the effects of strip filling and ecological thinning on the litterfall production and monthly dynamics of cypress plantations. In contrast with our hypothesis, both managemen<sup>t</sup> practices significantly reduced the annual production of total litter, leaf litter and reproductive organ litter, and only strip filling significantly increased twig litterfall and miscellaneous litterfall. Nevertheless, managemen<sup>t</sup> practices obviously changed the monthly dynamic patterns of twig litterfall, reproductive organ litterfall and miscellaneous litterfall but had few effects on total litterfall and leaf litterfall. Furthermore, the dominant factors affecting annual and monthly litterfall production were diameter at breast height and wind speed, respectively. These results confirmed the significant responses of litterfall production to managemen<sup>t</sup> practices in cypress plantations, but the investigation remains limited in terms of managemen<sup>t</sup> time and study continuity. There is a high need to further integrate carbon and nutrient inputs, address their cycling processes, and accurately evaluate the effects of strip filling and ecological thinning via long-term continuous research. Even so, the results presented here provide a primary reference for exploring the material mechanism by which managemen<sup>t</sup> practices affect cypress plantations.

**Supplementary Materials:** The following supporting information can be downloaded at: https: //www.mdpi.com/article/10.3390/f13101581/s1, Figure S1: Monthly average wind speed, air temperature, relative humidity and total precipitation during the study period; Figure S2: The proportion of broad leaf and needle leaf to total leaf litterfall in different plantations; Table S1: General descriptions of different plantations in the study site; Table S2: Repeated-measures ANOVA results for the responses of litterfall production to sampling time and plantations.

**Author Contributions:** Conceptualization, Q.W. (Qinggui Wu), Y.Y., C.Y. and J.H.; investigation, L.W., H.Y. and Q.W. (Qiang Wang); formal analysis, Y.Y., H.Y. and C.Y.; visualization, H.Y., Y.Y. and C.Y.; writing—original draft preparation, L.W., H.Y. and Y.Y.; writing—review and editing, Y.Y., J.Y., Q.D. and Q.W. (Qinggui Wu); funding acquisition, Q.W. (Qinggui Wu), C.Y., Y.Y. and Q.D. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was supported by the National Natural Science Foundation of China (32071747), the National Natural Science Foundation of Sichuan Province (2022NSFSC0087, 2022NS-FSC1173), the Open Fund of Ecological Security and Protection Key Laboratory of Sichuan Province, Mianyang Normal University (ESP2203) and the Research Fund of Mianyang Normal University (QD2020A18).

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Acknowledgments:** We are grateful to the Ecological Security and Protection Key Laboratory of Sichuan Province.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
