Tree plantations with native species combine economic and environmental gains but are still underrepresented in the plantations of tropical countries. In Brazil, is one of the most relevant native species considered for plantation. This conifer characterizes the mixed rainforests from southeast of South America, which were overexploited over the 20th to early 21st century due to the valuable timber of . These forests were largely converted into agriculture and exotic ( spp.) plantations, thus threatening with extinction. Nowadays, the timber of is still highly sought after in Brazil, despite the harvesting of remnant populations being restricted by law. Increasing plantations would benefit its conservation by increasing its coverage in the landscapes and diminishing illegal logging pressure on native forest remnants. A comprehensive investigation of growth and related controlling factors is lacking for plantations. Here, we describe the growth variability of trees on stands established in the state of Rio Grande do Sul (RS), and investigate environmental and plantation factors that influence in the Basal Area Increment (BAI) for each tree (BAI) and in a given stand (BAI). Based on the analysis of legal certification applications by the State's environmental agency, we selected 97 stands, totaling 5521 trees, distributed across RS. The mean diameter increment of the stands was 1.02 cm/year and the mean BAI was 58.32 cm²/ha/year. We found large BAI variability within and between stands across RS. Regression Tree Modelling showed that BAI was mostly explained by plantation stand density and soil type. The logarithmic density vs. tree diameter relationship, or stand density index, indicated a slope of −1.5807, similar to many other tree species. Besides that, many stands seemed to be understocked, potentially because of poor planting success or initial planting density. Future approaches including genetic factors and management should improve the knowledge of the silvicultural potential of to conservation use.

中文翻译：

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南洋杉人工林树木生长的区域变异和决定因素

本地树种种植园结合了经济和环境效益，但在热带国家的种植园中所占比例仍然不足。在巴西，它是考虑种植的最相关的本地物种之一。这种针叶树是南美洲东南部混合雨林的特征，由于珍贵的木材，这些雨林在 20 世纪至 21 世纪初遭到过度开发。这些森林大部分被转变为农业和外来种植园，因此面临灭绝的威胁。如今，尽管法律限制剩余木材的采伐，但巴西木材仍然受到高度追捧。增加种植园将增加其在景观中的覆盖范围并减少对原生森林残余物的非法采伐压力，从而有利于其保护。缺乏对种植园生长和相关控制因素的全面调查。在这里，我们描述了南里奥格兰德州 (RS) 州建立的林分上树木的生长变异性，并调查了影响每棵树 (BAI) 和给定情况下的断面积增量 (BAI) 的环境和种植园因素。站（BAI）。根据对国家环境机构合法认证申请的分析，我们选择了97个林分，总计5521棵树，分布在RS各地。林分平均直径增量为 1.02 厘米/年，平均 BAI 为 58.32 平方厘米/公顷/年。我们发现 RS 内和林间之间的 BAI 差异很大。回归树模型表明，BAI 主要由人工林密度和土壤类型来解释。对数密度与树木直径的关系，或林分密度指数，表明斜率为-1.5807，与许多其他树种相似。除此之外，许多林地似乎库存不足，可能是由于种植成功率不佳或初始种植密度所致。未来的方法，包括遗传因素和管理，应提高对保护利用的造林潜力的认识。