Abstract

The use of an appropriate design is a very important aspect of agroforestry experimentation. Since different species of trees may interact spatially, plots in agroforestry could be connected through network of trees which would create non-directional adjacency effects on a plot. Hence, there is a need to take the “direct effect of trees” and “tree network effects” on the crop into account when designing an agroforestry experiment. Tree network effect refers to the influence a tree exerts on the surrounding plots as a result of adjacency of the plots. In this paper, a class of network designs incorporating effects of trees from adjacent plots has been obtained. The characterization properties of the designs have also been studied. The designs are found to be variance balanced for the estimation of direct as well as network effects of trees. They are also highly efficient designs, and hence, are recommended for agroforestry experimentation with multiple tree species and a single crop.

摘要

使用适当的设计是农林业试验的一个非常重要的方面。由于不同种类的树木可能在空间上相互作用，农林业中的地块可以通过树木网络连接起来，这将在地块上产生非方向性的邻接效应。因此，在设计混农林业试验时，需要考虑到“树木的直接影响”和“树木网络效应”对作物的影响。树网效应是指一棵树由于相邻地块而对周围地块产生的影响。在本文中，已经获得了一类结合了相邻地块树木影响的网络设计。还研究了设计的特征特性。发现这些设计在估计树木的直接效应和网络效应时是方差平衡的。