城市中的荒野

綜合一些國(guó)際組織或一些國(guó)家機(jī)構(gòu)對(duì)荒野的定義來(lái)看，荒野指的是人類沒有或者僅僅輕微干預(yù)的區(qū)域，在這個(gè)區(qū)域中，自然完全是按照本身的規(guī)律進(jìn)行著演變。

今天地球表面的陸地范圍已有83%的土地被人類開發(fā)利用，而且受到人類影響和干預(yù)的區(qū)域還在擴(kuò)大，所以地球上符合荒野定義的區(qū)域占陸地面積的比率已經(jīng)不多，并且還將越來(lái)越少。由此看來(lái)，整個(gè)人類社會(huì)發(fā)展的過程，就是人類不斷拓展、荒野不斷退縮的過程。

然而地球上還有一些土地，這里曾經(jīng)由于人類的各種開發(fā)和建造完全改變了原有的天然狀況，但當(dāng)人類不再施加影響之后，土地逐漸荒蕪，植被開始萌發(fā)，經(jīng)過持續(xù)地演替發(fā)展、各種物種不斷在此棲息，形成了具有荒野特征和屬性的景觀。

荒野，我們可以理解為自然的一種狀態(tài)。未經(jīng)人工干預(yù)或只有極少人工干預(yù)的區(qū)域可以是荒野；曾經(jīng)受到人工影響，但當(dāng)人為控制不再繼續(xù)，自然重新獲得控制權(quán)，土地按自身進(jìn)程進(jìn)行演變的區(qū)域也可以是荒野，前者被稱為初級(jí)荒野，后者為次級(jí)荒野。

城市中會(huì)有荒野嗎？在全球范圍內(nèi)，越來(lái)越多的人生活在城市之中，但是大多數(shù)人并不了解荒野，許多人會(huì)將荒野與“雜亂荒蠻”對(duì)應(yīng)，并認(rèn)為這樣的“野地”與我們所追求的方便、舒適和優(yōu)美的城市生活格格不入。許多城市管理者也會(huì)覺得荒野會(huì)損害城市的景觀及風(fēng)貌，在管理上也有一定困難。于是在城市迅速更新和擴(kuò)張過程中，城市及周邊大量呈現(xiàn)出自然面貌的荒野地或被徹底開發(fā)用于城市建設(shè)，或被改造為人工建造和人工管理的公園綠地。如果哪座城市中還能保存有初級(jí)荒野，那真是這座城市的幸運(yùn)。

但是城市中總會(huì)有因?yàn)楦鞣N原因被長(zhǎng)期廢棄無(wú)人管理的地段，如撂荒的田園、時(shí)常被水淹的河灘、被遺棄的場(chǎng)地或棕地等，從而形成了以自然而非人為主導(dǎo)的土地，這里的植物在自然演替過程中呈現(xiàn)出自由生長(zhǎng)的景象，這些地塊就是一種次級(jí)荒野。

如1999—2003年間，杭州玉皇山南麓一個(gè)名叫江洋畈的山谷成了西湖一次大規(guī)模疏浚存積淤泥的泥庫(kù)。隨后，在無(wú)人干擾的情況下，植物從淤泥中萌發(fā)出來(lái)，并隨著泥庫(kù)表面水量的變化呈現(xiàn)出獨(dú)特的自然演替過程，逐步形成了城市中一片由自然主導(dǎo)的荒野。

荒野之于城市的價(jià)值主要體現(xiàn)在其經(jīng)濟(jì)和高效的生態(tài)服務(wù)功能。由自然過程主導(dǎo)的荒野是一種最接近自然狀態(tài)的、穩(wěn)定的生態(tài)系統(tǒng)。自然狀態(tài)下的植物群落能夠自發(fā)生長(zhǎng)，相互競(jìng)爭(zhēng)適應(yīng)，從而形成適宜場(chǎng)地環(huán)境的種群形態(tài)和穩(wěn)定、優(yōu)越的生態(tài)系統(tǒng)。在維持和改善城市生態(tài)環(huán)境、為當(dāng)?shù)貏?dòng)植物提供適宜的生境、豐富城市棲息地類型和物種多樣性方面，荒野較之那些精心設(shè)計(jì)、建造和管理的城市綠地更具有優(yōu)越性。

10年前，杭州市利用江洋畈淤泥庫(kù)建造了生態(tài)公園，公園的設(shè)計(jì)充分尊重、維護(hù)、順應(yīng)并展示了這片次生荒野的自然演變進(jìn)程。如今，公園呈現(xiàn)的是充滿自然生機(jī)、動(dòng)態(tài)變化的景觀。幾十種鳥類棲息于此，泥塘中生活著野生的魚、小龍蝦、蟹，自然觀測(cè)者們?cè)谶@里共發(fā)現(xiàn)了56種蝴蝶。作為一個(gè)自然系統(tǒng)能夠按照自身規(guī)律進(jìn)行演替的公園，江洋畈充分展現(xiàn)了它在城市中的生態(tài)價(jià)值。

實(shí)際上在高密度的城市中，即使是比江洋畈面積更小的荒野地也都能發(fā)揮特殊的生態(tài)功能?，F(xiàn)在，許多國(guó)家都在充分保護(hù)城市中由于各種原因形成的微小次生荒野，同時(shí)將一些環(huán)境受損的土地進(jìn)行“再野化”的生態(tài)修復(fù)，也會(huì)在新建的大尺度公園中的某個(gè)區(qū)域，模擬荒野的特征建造一種類荒野景觀，讓自然在城市中自由發(fā)展，為當(dāng)?shù)氐奈锓N提供棲息的環(huán)境，也為城市展現(xiàn)不斷生長(zhǎng)變化、充滿自然氣息的景觀。

除了生態(tài)價(jià)值外，城市中的荒野同樣具有游覽、科普和科學(xué)研究的意義。這些小片荒野的存在，讓我們知道如果沒有人類干擾城市中自然應(yīng)該有的狀態(tài)，也讓我們反思應(yīng)該如何設(shè)計(jì)和管理城市中的自然。

一座健康的城市必然是一座綠色的城市，但是，如果城市僅僅具有充足的綠量，也未必就一定能成為一座生態(tài)系統(tǒng)健全的城市。城市之中那些以滿足人的各種使用需要為目的，依據(jù)人的審美標(biāo)準(zhǔn)建造和管理的生態(tài)結(jié)構(gòu)單一、維護(hù)費(fèi)用高昂的綠地，其生態(tài)系統(tǒng)服務(wù)功能都是極為有限的。麥克哈格（Ian Lennox McHarg）在《設(shè)計(jì)結(jié)合自然》中曾提到，城市中存在兩個(gè)重要的系統(tǒng)，即自然的系統(tǒng)與人工的系統(tǒng)，優(yōu)秀的城市中這兩個(gè)系統(tǒng)是互相平衡的。而自然的系統(tǒng)并非指綠色的自然，而是指能夠真正按照自己的演變進(jìn)程發(fā)展的自然。城市中的荒野就屬于這一類自然。我們應(yīng)該深知荒野對(duì)于城市的意義，更加珍惜城市中的荒野，也更應(yīng)該能夠欣賞荒野所獨(dú)具的動(dòng)態(tài)變化和自由萌發(fā)的美。

PREFACE

Wilderness in the City

Regarding to definition of wilderness by several international organizations and national institutions，the wilderness refers to the area where human beings did not intervene or only slightly intervened with，in which nature naturally evolves according to its own laws.

Today，83% of the land surface of the earth has been exploited by human being，and the area affected by human influence and intervention is still expanding.Therefore，the proportion of land on earth that meets the definition of the wilderness is not much，and will be on the decrease.From this point of view，the whole process of social development is the process of continuous expansion of human beings and constant drawing back of wilderness.

However，there are still some land on the earth where the original natural condition has been completely changed due to the various development and construction of human beings，yet when human no longer exert influence，the land would gradually go wild with the vegetations germinating.It develops through the continuous succession，the inhabitation of various species，forming a landscape with wilderness characteristics and attributes.

The wilderness，we can understand as a state of nature.Areas without human intervention or with minimal human intervention can be wilderness.It can also be wilderness where had been artificially affected，but later it could evolve according to its own process when artificial control stopped and nature regained the control.The former can be called the primary wilderness，and the latter is the secondary wilderness.

Is there wilderness in the city? On a global perspective，more and more people are living in cities，but most people don't understand the wilderness well.Many people will associate the wilderness with“disordered and uncultivated” and think that such “wild land” is incompatible with the expected convenience，comfort and beautiful city life.Many city managers will also feel that the wilderness will damage the city's landscape and style，also there are certain difficulties in management.Therefore，in the process of rapid urban renewal and expansion，some wilderness in the city and its surrounding areas were developed or used for urban construction，or some were transformed into artificially constructed and manually managed parks.So，it is so lucky for a city to own a primary wilderness.

However，there are always abandoned areas in the city that have been discarded for a long time，such as abandoned farmlands，beaches being frequently flooded，brownfields，etc.，forming a nature controlled rather than human oriented land.Here plants present its free-growth during natural succession，can be called a secondary wilderness.

For example，between 1999 and 2003，a valley named Jiang Yang Fan in the south of Yuhuang Mountain in Hangzhou of China became a mud deposit place during a silt-dredging project of the West Lake.Subsequently，in the absence of human interference，the plants sprouted out of the silt and showed a unique natural succession process with the change of the water volume，gradually forming a wilderness in the city dominated by nature.

The value of wilderness to city is mainly embodied in its economic and efficient ecological service functions.The wilderness dominated by natural processes is a stable ecosystem that is closest to its natural state.The plant communities in natural conditions can grow spontaneously and adapt to each other in competition，finally to form a population suitable for site environment and a stable ecosystem.The wilderness is superior to the well-designed，constructed and manually managed urban green spaces in terms of maintaining and improving urban ecological environment，providing suitable habitats for local animals and plants，and enriching the diversity of urban habitats.

Based on the Jiang Yang Fan silt reservoir，an ecological park was built ten years ago in Hangzhou，which was designed to respect，maintain，accommodate and demonstrate the natural evolution of this secondary wilderness.Nowadays，the landscape full of natural vitality and dynamic changes is presented in the park，with dozens of birds inhabiting here.Wild fishes，crayfishes and crabs are living in the mud ponds.Natural observers have found 56 species of butter flies here.As a park where the natural system can succeed in accordance with its own laws，Jiang Yang Fan fully demonstrates its ecological value in the city.

In fact，in high-density cities，even the wilderness with smaller area than Jiang Yang Fan can also provide special ecological service.Nowadays，many countries are trying to protect the micro-secondary wilderness in cities.At the same time，some environmentally damaged land is being “re-wilded” for ecological restoration.Meanwhile，the wilderness-like landscape are widely welcomed to be built to simulate the characteristics of wilderness in a certain area of the newly built large-scale park which will allow nature to develop freely in the city，providing habitats for local species，and also showcasing the constantly growing and changing landscape full of natural atmosphere for the city.

Besides the ecological value，the wilderness in city also owns the significance of tourism，science education and scientific research.The existence of these small wilderness let us know the state of nature without human interference，and also let us reflect on how to design and manage the nature in the city.

A healthy city is bound to be a green city.However，if the city only has sufficient green quantity，it may not become a city with healthy ecosystem.In cities，those green spaces with single ecological structure and high maintenance cost，which are built and managed according to human aesthetic standards and to meet the various needs of people，have extremely limited their ecosystem service functions.Ian Lennox McHarg mentioned in Design with Nature that there are two important systems in the city，namely the natural system and the artificial system，which would be very well-balanced in good cities.And the natural system does not refer to the green nature，but the nature that can freely develop according to its own evolution process.The wilderness in the city belongs to the latter.We should be fully aware of the significance of wilderness to the city，cherish it，and appreciate its unique beauty of dynamic changes and free germination.

Translator:WANG Xiyue

Chief Editor:Prof.Dr-Ing.WANG Xiangrong

July 25th，2019