J Plant Ecol ›› 2020, Vol. 13 ›› Issue (1): 12-19.DOI: 10.1093/jpe/rtz042

• Research Articles • Previous Articles     Next Articles

Pure and mixed plantations of Persian walnut (Juglans regia L.) for high quality timber production in Chile, South America

Verónica Loewe-Muñoz1,*, , Mónica Balzarini2 and Marta Ortega González3   

  1. 1Chilean Forest Institute (INFOR), Metropolitan Office, Sucre 2397, Ñuñoa, Santiago, Chile, 2CONICET Biometry Unit, College of Agriculture, Universidad Nacional de Córdoba, Ciudad Universitaria, CC509, CP 5000, Córdoba, Argentina, 3Chilean Forest Institute (INFOR), Biobío Office, Camino a Coronel Km 7.5, San Pedro de la Paz, Concepción, Chile
  • Received:2019-02-26 Revised:2019-07-17 Accepted:2019-08-20 Online:2019-08-22 Published:2020-02-01

Abstract:

Aims

Persian walnut (Juglans regia L.), an interesting forest species for the veneering industry, requires adequate management to produce valuable high-quality logs. Since species associations and management level can improve stand productivity, the novelty of this work was to assess Persian walnut performance in different planting mixtures and in pure plantations conditioned to management intensity.

Methods

Growth, straightness and survival measurements were taken annually for 7 years after planting pure and mixed plantations under two contrasting management scenarios. Diseases were recorded at Age 7 in all plantations. Under each management intensity, besides the monoculture, three mixtures were tested: a mixture of only main forest species, main forest species plus one arboreal companion species, Black alder (Alnus glutinosa L.) and main species plus the shrub Russian olive (Elaeagnus angustifolia L.) as nurse species. A test of interaction between plantation type and management scenario was conducted using repeated growth data.

Important Findings

The interaction was significant, indicating the presence of different mechanisms underlying plantation effects under high and low management level. Compared with pure plantations, Persian walnut associated with the nurse shrub exhibited 78% higher height and 53% higher diameter growth in plantations under low management. Health benefits (lower presence of walnut blight than in the monoculture) and better straightness were also found in the association including the shrub when the management intensity was not high. These beneficial effects in the presence of Russian olive were not present under high management intensity (irrigation, fertilization, tutoring and frequent pruning). Site-specific designs for Persian walnut plantations would depend on the foreseen management intensity.

Key words: noble wood, monoculture, forest associations, companion species, Russian olive

摘要:
波斯胡桃(Juglans regia L.)是用于装饰工业的一种森林物种,需要适当的管理才能生产出经济效益好的高质量原木。由于种间关联和管理水平可以提高林分生产力,因此本研究的创新之处在于评估波斯胡桃在不同混合种植中以及在适度的管理强度的纯人工林中的表现。在两种截然不同的管理方案下种植纯林和混交林后,连续7年每年对波斯胡桃的生长、直度和存活率进行测定。在第7年时,记录所有人工林中病害情况。在每种管理强度下,除纯林外,检验三种混交林:仅与主要森林物种混交、主要森林物种和黑桤木(Alnus glutinosa L.,伴生种)混交,以及主要物种和灌木俄罗斯橄榄(Elaeagnus angustifolia L.,保育种)混交。利用重复生长数据对人工林类型与管理方案之间的交互作用进行检验。研究发现人工林类型与管理方案的交互作用显著,表明在管理水平高和低的条件下,人工林效应存在不同的机制。与纯林相比,在低管理水平下,有保育灌木混交的波斯胡桃的树高增加了78%、直径生长增加了53%。同样,在管理强度不高的情况下,与灌木混交有更多的健康益处(胡桃枯萎病的发生率低于单一栽培)和更好的直度。在高管理强度下(灌溉、施肥、抚育和频繁修剪),与俄罗斯橄榄混交时这些有益效应消失。因此,波斯胡桃种植园的具体选址设计取决于可预见的管理强度。

关键词: 高质量木材, 单一栽培, 森林协会, 伴生种, 俄罗斯橄榄