Enhancing Tree Performance Through Species Mixing: Review of a Quarter-Century of TreeDivNet Experiments Reveals Research Gaps and Practical Insights

IF 9 1区农林科学 Q1 FORESTRY

Current Forestry Reports Pub Date : 2024-01-26 DOI:10.1007/s40725-023-00208-y

{"title":"Enhancing Tree Performance Through Species Mixing: Review of a Quarter-Century of TreeDivNet Experiments Reveals Research Gaps and Practical Insights","authors":"","doi":"10.1007/s40725-023-00208-y","DOIUrl":null,"url":null,"abstract":"<h3>Abstract</h3> <span> <h3>Purpose of Review</h3> <p>International ambitions for massive afforestation and restoration are high. To make these investments sustainable and resilient under future climate change, science is calling for a shift from planting monocultures to mixed forests. But what is the scientific basis for promoting diverse plantations, and what is the feasibility of their establishment and management? As the largest global network of tree diversity experiments, TreeDivNet is uniquely positioned to answer these pressing questions. Building on 428 peer-reviewed TreeDivNet studies, combined with the results of a questionnaire completed by managers of 32 TreeDivNet sites, we aimed to answer the following questions: (i) How and where have TreeDivNet experiments enabled the relationship between tree diversity and tree performance (including productivity, survival, and pathogen damage) to be studied, and what has been learned? (ii) What are the remaining key knowledge gaps in our understanding of the relationship between tree diversity and tree performance? and (iii) What practical insights can be gained from the TreeDivNet experiments for operational, real-world forest plantations?</p> </span> <span> <h3>Recent Findings</h3> <p>We developed a conceptual framework that identifies the variety of pathways through which target tree performance is related to local neighbourhood diversity and mapped the research efforts for each of those pathways. Experimental research on forest mixtures has focused primarily on direct tree diversity effects on productivity, with generally positive effects of species and functional diversity on productivity. Fewer studies focused on indirect effects mediated via biotic growing conditions (e.g. soil microbes and herbivores) and resource availability and uptake. Most studies examining light uptake found positive effects of species diversity. For pests and diseases, the evidence points mostly towards lower levels of infection for target trees when growing in mixed plantations. Tree diversity effects on the abiotic growing conditions (e.g. microclimate, soil properties) and resource-use efficiency have been less well studied to date. The majority of tree diversity experiments are situated in temperate forests, while (sub)tropical forests, and boreal forests in particular, remain underrepresented.</p> </span> <span> <h3>Summary</h3> <p>TreeDivNet provides evidence in favour of mixing tree species to increase tree productivity while identifying a variety of different processes that drive these diversity effects. The design, scale, age, and management of TreeDivNet experiments reflect their focus on fundamental research questions pertaining to tree diversity-ecosystem function relationships and this scientific focus complicates translation of findings into direct practical management guidelines. Future research could focus on (i) filling the knowledge gaps related to underlying processes of tree diversity effects to better design plantation schemes, (ii) identifying optimal species mixtures, and (iii) developing practical approaches to make experimental mixed plantings more management oriented.</p> </span>","PeriodicalId":48653,"journal":{"name":"Current Forestry Reports","volume":"35 1","pages":""},"PeriodicalIF":9.0000,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Current Forestry Reports","FirstCategoryId":"97","ListUrlMain":"https://doi.org/10.1007/s40725-023-00208-y","RegionNum":1,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"FORESTRY","Score":null,"Total":0}

引用次数: 0

Abstract

Purpose of Review

International ambitions for massive afforestation and restoration are high. To make these investments sustainable and resilient under future climate change, science is calling for a shift from planting monocultures to mixed forests. But what is the scientific basis for promoting diverse plantations, and what is the feasibility of their establishment and management? As the largest global network of tree diversity experiments, TreeDivNet is uniquely positioned to answer these pressing questions. Building on 428 peer-reviewed TreeDivNet studies, combined with the results of a questionnaire completed by managers of 32 TreeDivNet sites, we aimed to answer the following questions: (i) How and where have TreeDivNet experiments enabled the relationship between tree diversity and tree performance (including productivity, survival, and pathogen damage) to be studied, and what has been learned? (ii) What are the remaining key knowledge gaps in our understanding of the relationship between tree diversity and tree performance? and (iii) What practical insights can be gained from the TreeDivNet experiments for operational, real-world forest plantations?

Recent Findings

We developed a conceptual framework that identifies the variety of pathways through which target tree performance is related to local neighbourhood diversity and mapped the research efforts for each of those pathways. Experimental research on forest mixtures has focused primarily on direct tree diversity effects on productivity, with generally positive effects of species and functional diversity on productivity. Fewer studies focused on indirect effects mediated via biotic growing conditions (e.g. soil microbes and herbivores) and resource availability and uptake. Most studies examining light uptake found positive effects of species diversity. For pests and diseases, the evidence points mostly towards lower levels of infection for target trees when growing in mixed plantations. Tree diversity effects on the abiotic growing conditions (e.g. microclimate, soil properties) and resource-use efficiency have been less well studied to date. The majority of tree diversity experiments are situated in temperate forests, while (sub)tropical forests, and boreal forests in particular, remain underrepresented.

Summary

TreeDivNet provides evidence in favour of mixing tree species to increase tree productivity while identifying a variety of different processes that drive these diversity effects. The design, scale, age, and management of TreeDivNet experiments reflect their focus on fundamental research questions pertaining to tree diversity-ecosystem function relationships and this scientific focus complicates translation of findings into direct practical management guidelines. Future research could focus on (i) filling the knowledge gaps related to underlying processes of tree diversity effects to better design plantation schemes, (ii) identifying optimal species mixtures, and (iii) developing practical approaches to make experimental mixed plantings more management oriented.

查看原文本刊更多论文

通过树种混交提高树木性能：回顾 TreeDivNet 四分之一世纪的实验，揭示研究差距和实践启示

摘要审查目的国际社会对大规模植树造林和恢复森林雄心勃勃。为了使这些投资在未来气候变化的情况下具有可持续性和复原力，科学界呼吁从种植单一树种转向种植混交林。但是，推广多样化人工林的科学依据是什么？作为全球最大的树木多样性实验网络，TreeDivNet 在回答这些迫切问题方面具有得天独厚的优势。以 428 项经同行评审的 TreeDivNet 研究为基础，结合 32 个 TreeDivNet 站点的管理人员填写的问卷调查结果，我们旨在回答以下问题：(i) TreeDivNet 实验如何以及在哪些地方对树木多样性与树木性能（包括生产力、存活率和病原体损害）之间的关系进行了研究？(iii) 从 TreeDivNet 实验中可以获得哪些实用见解，用于实际操作的人工林？最新研究结果我们建立了一个概念框架，确定了目标树木性能与当地邻近地区多样性相关的各种途径，并绘制了每种途径的研究工作图。有关混交林的实验研究主要集中于树木多样性对生产力的直接影响，一般来说，物种和功能多样性对生产力有积极影响。较少研究关注通过生物生长条件（如土壤微生物和食草动物）以及资源可用性和吸收的间接影响。大多数关于光吸收的研究发现，物种多样性具有积极影响。在病虫害方面，大多数证据表明，在混交种植园中生长的目标树木感染率较低。迄今为止，有关树木多样性对非生物生长条件（如小气候、土壤特性）和资源利用效率影响的研究较少。大多数树木多样性实验都是在温带森林中进行的，而（亚）热带森林，尤其是北方森林的代表性仍然不足。总结 TreeDivNet 提供了支持混合树种以提高树木生产力的证据，同时确定了驱动这些多样性效应的各种不同过程。TreeDivNet 实验的设计、规模、树龄和管理反映了其对有关树木多样性-生态系统功能关系的基础研究问题的关注，这种科学关注使得将研究结果转化为直接的实际管理指南变得更加复杂。未来的研究重点可放在：(i) 填补与树木多样性效应的基本过程有关的知识空白，以更好地设计种植方案；(ii) 确定最佳物种混合物；(iii) 开发实用方法，使实验性混合种植更注重管理。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Current Forestry Reports Agricultural and Biological Sciences-Ecology, Evolution, Behavior and Systematics

CiteScore

15.90

自引率

2.10%

发文量

期刊介绍： Current Forestry Reports features in-depth review articles written by global experts on significant advancements in forestry. Its goal is to provide clear, insightful, and balanced contributions that highlight and summarize important topics for forestry researchers and managers. To achieve this, the journal appoints international authorities as Section Editors in various key subject areas like physiological processes, tree genetics, forest management, remote sensing, and wood structure and function. These Section Editors select topics for which leading experts contribute comprehensive review articles that focus on new developments and recently published papers of great importance. Moreover, an international Editorial Board evaluates the yearly table of contents, suggests articles of special interest to their specific country or region, and ensures that the topics are up-to-date and include emerging research.