刊首语

郑晓笛

2009年，在我开启棕地再生领域博士研究的初期，无论是与风景园林专业的专家沟通，还是向政府相关部委及环境工程领域的领导专家请教，得到的第一句反馈基本都是“棕地是什么？”10年间，不仅“棕地”这个概念在中国逐渐被认识和接受，政府、行业与相关专业对棕地污染修复与再利用领域的关注热度、实践探索与研究推进更是发展迅猛。这一方面是因为中国土壤污染问题所带来的迫切性，另一方面也是响应人民大众随着经济水平升高而日益提升的环保意识与对美好人居环境需求的呼声。

2018年“世界土壤日”中国活动的主题为“土壤污染防治”，第一届全国土壤修复大会同期在南京召开。我有幸作为规划设计领域的唯一嘉宾受邀参加“城乡空间规划、绿色金融与修复科技创新”论坛并发言。论坛嘉宾来自各个行业和领域，包括政府投资建设单位、科技园区管委会、民营环境修复企业、世界银行专员、资深环境修复国企和高校大数据实验室等。棕地再生的复杂性与长期性要求跨学科、跨领域、跨行业合作的特征愈发凸显。10年前，当我希望向资深土壤修复专家求教如何促进跨学科合作时，得到的是“我们不需要合作”的回答。而在2018年的论坛上，最后的对话讨论环节中，一位环境修复公司的专家大声呼吁要进行体制机制的创新，以使规划设计领域人员能够在早期参与到棕地的修复改造决策过程中。作为棕地再生领域发展的亲历者，能够听到来自环境工程修复行业这样的呼声，心情是激动而复杂的。在全行业的努力下，风景园林专业在棕地再生领域的价值与贡献正在被逐渐认识，然而我们是否做好了迎接这一挑战的准备？

30年前，美国哈佛大学设计学院(GSD)举办的“制造场地”国际会议第一次把德国北杜伊斯堡景观公园介绍到北美，第一次邀请石油企业代表来GSD进行学术交流，第一次把棕地作为风景园林专业学术会议的核心议题。在此之后，棕地成为众多重要景观项目的对象，包括悉尼和伦敦的奥林匹克公园等。20世纪90年代后期兴起的景观都市主义，尽管本身在学术界饱受争议，但棕地以其复杂性与大尺度而成为其中备受关注的探讨类型，美国清溪垃圾填埋场的改造更是被列举为“成熟的景观都市主义作品的代表”。在项目类型上，国外棕地再生实践除了常见的工业闲置地、矿业废弃地与垃圾填埋场，还包括军事用地、废弃机场，甚至墓地等。由于法规标准相对健全、行业分工与职业制度相对成熟，风景园林师在项目中的角色是相对明确的。项目团队基本由多专业的人员构成，污染的勘测与修复由专门的环境工程团队负责，风景园林师需要统筹各方信息以服务于最终的场所营造，常常在团队中起主导作用。

中国的情况则不同。2019年1月1日，《土壤污染防治法》终于开始实施，但相关的技术标准与规范还在修订或制定的过程中。棕地再生项目的团队构成可能千差万别，设计方在其中所起的作用可能由很多主观而随机的因素决定。有机会参与其中的设计团队，也可能因为从未接触过此类项目而感到力不从心。

在棕地再生领域，中国风景园林师所面临的挑战更为艰巨，责任也更加重大。我们也许可以从2个方面来更好地应对这一挑战(本期5篇主题文章也以此思路进行组织)，一方面聚焦于风景园林的专业内核，包括对学术研究的最新进展、趋势与未来可能研究方向的把握；以及专业领域的实践，如垃圾填埋场封场再生策略的探索、废弃工业用地与医院的改造更新。另一方面是要更加有意识地关注可能的外延领域，如新的土壤污染防治立法对城乡绿地系统可能产生怎样的影响并带来什么机遇，从区域的层面如何更加有效地使相对独立的场地改造产生合力，以贡献于更大范围的开放空间与生态系统构建。

中国的棕地再生领域研究仍处在起步阶段，发展前景广阔。正如国际风景园林师联合会新上任的詹姆斯·海特(James Hayter)主席在他为本期特别供稿的文章最后所说：“与其将城市棕地视为遗留下来、被抛弃和不受欢迎的地方，不如说它们反而是风景园林领域中令我们的城市更加人性化和更具有绿化价值的瑰宝。”

In 2009, when I started my doctoral research in the field of brownfield regeneration,whether it was to communicate with experts in the landscape architecture profession, or to consult with relevant government officials and environmental engineering experts, the first feedback was often "what is brownfield?" In the past 10 years, not only has the concept of "brownfield" been gradually recognized and accepted in China, but the government,industry and related professions have been pushing forward research and practice rapidly in the field of brownfield remediation and reuse. This development is due to the urgency brought about by China's soil pollution problem, and on the other hand, it is also responding to the increasing awareness of environmental protection and the demand for a better living environment of the people as the economic level rises.

The theme of the "World Soil Day" China event in 2018 is "Soil Pollution Prevention and Control". The first National Soil Remediation Conference was held in Nanjing at the same time. I had the honor to be invited as the only speaker of the planning and design field to participate and give a speech in the forum on "Urban and Rural Spatial Planning,Green Finance and Rehabilitation Technology Innovation". The forum speakers came from various fields and industries, including government investment and construction units, science and technology park management committees, private environmental remediation enterprises, World Bank commissioners, senior state environmental remediation enterprises, and university big data laboratories. The complexity and long-term nature of brownfield regeneration requires an increasingly cross-disciplinary, cross-field and crossindustry collaboration. Ten years ago, when I wanted to ask senior soil remediation experts about how to promote interdisciplinary cooperation, I got the answer "we don't need cooperation." In last year's forum, in the final round-table discussion, an environmental remediation company's executive called for innovation in institutional mechanisms to enable professionals in the planning and design field to participate in the brownfield regeneration and decision-making process at an early stage. As a witness to the development of brownfield regeneration, I have mixed feelings of both excitement and concern when hearing the voice from the environmental engineering sector. With the efforts of the entire landscape society, the value and contribution of landscape architecture in the field of brownfield regeneration is gradually being recognized, but are we ready to take on this challenge?

Thirty years ago, the International Conference on Manufactured Sites organized by Harvard University Graduate School of Design (GSD) introduced Duisburg-Nord Landscape Park in Germany to North America for the first time. For the first time, representatives of oil companies were invited to GSD for academic exchanges. For the first time, brownfield was the core issue of an academic conference on landscape architecture. Since then,brownfields have been the targets of many important landscape projects, including the Olympic Parks in Sydney and London. Due to its complexity and large scale, brownfield has become one of the hot topics of landscape urbanism that emerged in the late 1990s,despite the controversy of this theory in the academic circle. The transformation of the Fresh Kills Landfill in the United States is even listed as "the representative of mature landscape urbanism works". In terms of project types, foreign brownfield regeneration practices include not only common industrial vacant land, mining wasteland and landfills, but also military land, abandoned airports, and even cemeteries. Because the regulations and standards are relatively sound, and the responsibilities of various project members and requirements of professional conducts are specified, the role of landscape architects in the project is relatively clear. The project team is normally composed of multi-disciplinary professionals.The investigation and remediation of pollution are carried out by the dedicated environmental engineering team. Landscape architects need to synthesize all aspects of information to work for the final spatial design, and often play a leading role in the team.

The situation in China is quite different. On January 1, 2019, the Soil Pollution Prevention Law is finally in place, but the relevant technical standards and guidelines are still being revised or formulated. The composition of the brownfield regeneration project team may vary widely, and the role of the designer in it may be determined by many subjective and random factors. The design team that has the opportunity to participate in might also feel powerless because they have never been exposed to such projects.

In the field of brownfield regeneration, the challenges faced by Chinese landscape architects are more arduous and their responsibilities are even more important. We may be able to better cope with this challenge in two ways (the five thematic articles in this issue are also organized in this way): on the one hand, focusing on the professional core knowledge of landscape architecture, including the latest developments and trends in academic research, and the future research direction, and the practice of professional fields, such as the exploration of regeneration strategies for landfill site, abandoned industrial land and hospital renovation; on the other hand, it is necessary to pay more attention to possible extension areas, such as how the new soil pollution control legislation may affect the urban and rural green space system and what opportunities it may bring, and how to more effectively transform relatively independent sites from the regional level to produce synergies to contribute to a wider range of open spaces and ecosystems.

China's brownfield regeneration research is still in its infancy and has broad prospects for development. As the newly appointed IFLA President James Hayter said at the end of his special article for this issue, "rather than thinking of urban brownfields as left over,abandoned and unloved places, they are instead the jewels in our profession's role to humanise and green our cities."