Understanding the performance of agroforestry woody species in controlled and free grazing systems is crucial for scaling up agroforestry practices. The objective of this study was to identify and evaluate the determinants of agroforestry woody species composition and regeneration in free and controlled grazing systems in the Ethiopian highlands. Household and field surveys were conducted on 83 and 171 households selected from controlled grazing (CG) and free grazing (FG) systems, respectively. Woody species performance was compared between the two grazing systems using independent T-test. Seemingly unrelated regression (SUR) was used to identify the factors determining woody species density/abundance, diversity and regeneration. Most trees were grown for fuel wood and timber rather than for fodder. CG users owned more diversified species and abundant regenerates and mature trees/shrubs than FG users. The SUR results showed that herd size, farmland size, fencing, plantation of seedlings, education, wealth, grazing system, farmland distance from homestead and slope were the major factors affecting the composition and regeneration of species. Specifically the SUR results per-household indicated that woody species regeneration was highly affected by grazing system. Fencing is the common underlying factor positively affecting species diversity, regeneration and density of mature trees. Homestead distance from road and number of planted seedlings significantly affected density of regenerates and mature trees. Density of mature trees and species diversity were significantly affected by agroecology and slope. Woody species diversity was significantly affected by education, wealth, farmland size and project participation. Our findings revealed that the scaling up of woody species in agroforestry requires not only CG and favorable agroecology but also matching of agroforestry options with household and farmland characteristics.

了解农林业木本物种在受控和自由放牧系统中的表现对于扩大农林业实践至关重要。本研究的目的是确定和评估埃塞俄比亚高地自由和受控放牧系统中农林业木本物种组成和再生的决定因素。对分别从控制放牧 (CG) 和自由放牧 (FG) 系统中选出的 83 户和 171 户进行了住户和实地调查。使用独立 T 检验比较两种放牧系统之间的木本物种性能。看似无关的回归 (SUR) 用于确定决定木本物种密度/丰度、多样性和再生的因素。大多数树木是为了薪柴和木材而不是饲料而种植的。CG 用户比 FG 用户拥有更多样化的物种和丰富的再生和成熟的树木/灌木。SUR结果表明，畜群规模、农田规模、围栏、苗木种植、教育、财富、放牧制度、农田距宅基地的距离和坡度是影响物种组成和更新的主要因素。具体来说，每户的 SUR 结果表明，木本物种的再生受放牧制度的影响很大。围栏是对成熟树木的物种多样性、再生和密度产生积极影响的共同潜在因素。宅基地与道路的距离和种植的幼苗数量显着影响再生树和成熟树的密度。成熟树密度和物种多样性受农业生态和坡度的显着影响。木本物种多样性受到教育、财富、农田规模和项目参与的显着影响。我们的研究结果表明，在农林业中扩大木本物种不仅需要 CG 和有利的农业生态学，还需要将农林业选择与家庭和农田特征相匹配。