TAILIEUCHUNG - Constructing mortality models for natural forest state III in four provinces of the Central region, Vietnam

In this research, the dead trees were defined as the standing trees that died between the two occasions at which measurements were taken. The data on 300 subplots from 12 permanent sample plots were collected. The response variable was the number of dead trees per subplot. | Silviculture CONSTRUCTING MORTALITY MODELS FOR NATURAL FOREST STATE III IN FOUR PROVINCES OF THE CENTRAL REGION, VIETNAM Cao Thi Thu Hien Vietnam National University of Forestry In this research, the dead trees were defined as the standing trees that died between the two occasions at which measurements were taken. The data on 300 subplots from 12 permanent sample plots were collected. The response variable was the number of dead trees per subplot. The results suggest that we successfully developed the mortality model by using both generalized linear and generalized linear mixed models for count data to address the problem of overdispersion. Arithmetic mean diameter of the subplot, plot basal area, and provinces as a categorical variable were found to be the most significant explanatory variable. With the generalized linear model, we found that the Negative Binomial GLM was the most appropriate model for predicting the number of recruitment for three groups. From using the provinces as a grouping variable, we realized that the mean numbers of dead trees was different in the four different locations, namely the number of dead trees for group 1 and group 2 in Thua Thien Hue were the highest, while in Ha Tinh these were the lowest. With the generalized linear mixed model, the Negative Binomial GLMM solves overdispersion by treating a plot as a random effect. The GLMM with random intercept was selected as the equation for the direct prediction of dead trees across each of the two species groups, and for N. melliferum. The GLMM with a random slope was chosen for S. wightianum. Keywords: Generalized linear model, generalized linear mixed model, mortality model, Negative Binomial GLM, tropical rainforests. 1. INTRODUCTION Natural mortality of trees is a crucial process that determines forest dynamics (Rüger et al., 2011). When a tree dies, the reduced competition benefits the trees near the dead tree, positively affecting their growth (Yang et al, 2003); in addition, .

TAILIEUCHUNG - Chia sẻ tài liệu không giới hạn
Địa chỉ : 444 Hoang Hoa Tham, Hanoi, Viet Nam
Website : tailieuchung.com
Email : tailieuchung20@gmail.com
Tailieuchung.com là thư viện tài liệu trực tuyến, nơi chia sẽ trao đổi hàng triệu tài liệu như luận văn đồ án, sách, giáo trình, đề thi.
Chúng tôi không chịu trách nhiệm liên quan đến các vấn đề bản quyền nội dung tài liệu được thành viên tự nguyện đăng tải lên, nếu phát hiện thấy tài liệu xấu hoặc tài liệu có bản quyền xin hãy email cho chúng tôi.
Đã phát hiện trình chặn quảng cáo AdBlock
Trang web này phụ thuộc vào doanh thu từ số lần hiển thị quảng cáo để tồn tại. Vui lòng tắt trình chặn quảng cáo của bạn hoặc tạm dừng tính năng chặn quảng cáo cho trang web này.