Читать книгу North American Agroforestry - Группа авторов - Страница 100

It is true that we have made significant improvements in our understanding of ecological interactions in temperate agroforestry. As this chapter has revealed, we have information on above‐ and belowground interactions that define the ecological sustainability of some of the well‐known agroforestry practices such as alley cropping and silvopasture in the United States and other temperate regions of the world. We also have information on the management techniques that may reduce competitive interactions while enhancing complementarity in those systems. However, our knowledge is still limited in several areas. For example, despite much research examining resource competition, we still lack a deeper understanding of the interactive effects of multiple resources on system productivity in several agroforestry systems. Modeling has helped us understand multiple resource interactions to a great extent (Lovell et al., 2017), but continued acquisition of information at a range of scales is urgently needed. Although information on specific components and their interactions are important, we also need to pay attention to interactions of agroforestry systems with the biotic and abiotic components of the surrounding landscape matrix. Watershed‐level research and studies of agroforestry systems as wildlife habitats and corridors need to explore these relationships in detail.

Another area that needs immediate attention is the screening of species and germplasm for above‐ and belowground complementarity. Most of the improved germplasm currently used in agroforestry comes from breeding efforts for monoculture cropping systems. Breeding for crops and trees that can perform better under shade and under interspecific competition for water and nutrients needs to be initiated.

The available literature on facilitative interactions in temperate agroforestry is very limited. For example, the concept of hydraulic lift is yet to be experimentally proven in a temperate context. Information on the canopy and root architecture of many common agroforestry species is still not readily available. Dinitrogen fixation remains an unexplored and underutilized concept in many of the well‐studied temperate agroforestry systems.

A number of agroforestry practices have received little attention from the scientific community despite their popularity. For example, forest farming is an attractive agroforestry practice in many parts of the United States. However, ecological sustainability or component interactions have seldom been investigated in these systems. Similarly, incorporation of high‐value agronomic or horticultural crops into existing agroforestry practices or the design of new agroforestry systems also needs to be explored.