A Solution to the Lack of Urban Vegetation解決城市植被缺乏的方法

喬萍萍/譯

The relentless spread of buildings and roads turns urban areas into heat islands， discomforting residents and exacerbating dangerous heatwaves， which are in any case likely to become more frequent as the planet warms.

高樓和道路的瘋狂擴張將城市地區變成熱島，導致居民不適，加劇危險熱浪強度。隨著全球變暖，以上情況無論如何都有可能變得更加頻繁。

A possible answer to the problem of heat is trees. Trees cool things down. Besides transpiration， they provide shade. Their leaves have， after all， evolved to intercept sunlight， the motor of photosynthesis.

針對高溫問題，種樹是一個可行的解決方式。樹木可以降溫。除了蒸騰作用，樹木還提供陰涼，畢竟樹葉進化出了攔截光照的特性，而光照正是光合作用的動力。

To cool an area effectively， though， trees must be planted in quantity. In 2019 researchers at the University of Wisconsin found that American cities need 40% tree coverage to cut urban heat back meaningfully. Unfortunately， not all cities—and especially not those now springing up in the worlds poor and middle-income countries—are blessed with parks， private gardens or even ornamental street trees in sufficient numbers.

然而，要想給一個區域有效降溫，種植的樹木必須成大體量。2019年，威斯康星大學的研究員發現，美國城市的樹木覆蓋率達到40%才能有效給城市降溫。不幸的是，并不是所有的城市都有數量充足的公園、私人花園，或者行道樹，全球貧困和中等收入國家中正在興起的城市尤其欠缺植被。

Under the greenwood tree

綠林蔭下

One group of botanists believe they have at least a partial solution to this lack of urban vegetation. It is to plant miniature simulacra of natural forests， ecologically engineered for rapid growth. Over the course of a career that began in the 1950s their leader， Miya-waki Akira， a plant ecologist at Yokohama National University， in Japan， has developed a way to do this starting with even the most unpromising derelict areas.

一組植物學家認為，對于城市植被缺乏，至少存在可以解決部分問題的方案。這個方案便是建造天然林的微型模擬物，借助生態學手段快速造林。這組植物學家的領導者、日本橫濱國立大學的植物生態學家宮脅昭自20世紀50年代著手此事，他已經研究出一種方案，可以從最無望的廢棄區域開始試驗。

Dr Miyawakis insight was to deconstruct and rebuild the process of ecological succession1， by which bare land develops naturally into mature forest. Usually， the first arrival is grass. Shrubs sprout later， followed by small trees and， finally， larger ones. Incipient and mature woodlands therefore contain different species. The Miyawaki method skips some of the early phases and jumps directly to planting the kinds of species found in a mature wood.

宮脅博士的觀點是解構和重建生態演替過程，即裸地自然發展為成熟林的過程。通常情況下，最先出現的是草，隨后灌木發芽，接著是小樹，最后是大樹。因此，幼林地和成熟林地包含的物種不同。宮脅造林法跳過了早期幾個階段，直接種植成熟林地中的物種。

When starting a Miyawaki forest， those involved， who often refer to themselves as gardeners， first analyse the soil in which it will grow. If necessary， they improve it by mixing in suitable fertilisers. They then select 100 or so local plant species to deploy. These are chosen by surveying the nearby area on foot instead of relying on published guidebooks， which have a habit of being out of date or even simply wrong.

建造宮脅森林之初，參與這項工作的人——他們通常稱自己為“園工”——首先會分析待種土地的土壤。如果有必要，他們會在土壤中混入適當肥料來改善土質。接著，園工們會選擇100種左右的當地植物搭配種植。這些植物物種都是園工們實地調研周邊區域后選出來的，沒有參考已出版的指南，因為這些指南通常已過時，甚至是完全錯誤的。

Using a wide mix of species， not all of them trees， is important. Most plantations， having been created for commercial purposes， are monocultures. But trees， shrubs and ground-covering herbs all coexist in natural forests， and the Miyawaki versions therefore have this variety from the start. Not only does that pack more greenery into a given space， it also encourages the plants to grow faster—for there are lots of positive ecological relations in a natural forest. Vines rely on trees for support. Trees give shade to shrubs. And， beneath the surface， plants roots interact with each other， and with soil fungi， in ways that enable a nutrient exchange which is only now beginning to be understood.

很重要的一點是，宮脅森林中要混種各種各樣的植物，而非全都種上樹。大多數為商業目的而建的種植園里種的都是單一植物物種，但是天然林中樹木、灌木和地被草本植物共存，因此宮脅森林從一開始就體現了這種多樣性。這樣不僅能在給定的空間里種植更多綠色植物，還能加速植物生長——因為天然林中存在許多積極的生態關系。例如：樹木給藤本植物以支撐，還能為灌木遮蔭；地表之下，植物根系之間相互作用，還與土壤真菌相互作用，以各種方式交換養分，而這一點人們才剛剛有所了解。

After selecting their species， the gardeners gather seeds and plant them at random， rather than in rows. And they plant at high density. The seedlings therefore have to fight for sunlight， so only the fastest-growing survive. Trees planted in this way can shoot up2 as much as 14% more rapidly than normal. For three years， the gardeners water and nurture their handiwork. Then it is left to fend for itself3. A couple of decades later the whole thing reaches maturity.

選好植物物種后，園工們收集種子，但不會成行播種，而是隨意播種，種植密度也很高。因此，幼苗必須爭奪光照，只有生長最快的才能存活。以這種方式種植的樹木生長起來比正常情況下快14%。播種后的3年里，園工們會澆灌、培育他們親手種下的植物，隨后便任其自行生長。幾十年后，整個森林便成熟了。

Dr Miyawaki has supervised the planting of more than 1，500 of these miniature forests， first in Japan， then in other parts of the world. Others are now following in his footsteps. India is particularly keen. In Mumbai， more than 200，000 trees are found in Miyawaki forests throughout the city and its suburbs. In Bangalore， more than 50，000. A group in Chennai has set up 25 such forests. The authorities in Tirunelveli， in the countrys south， use the Miya-waki method to create green cover in the citys schools. Hyderabad started growing the largest individual forest of the lot， across four hectares， in 2020.

宮脅博士已經指導建造了1500多個微型森林，先是在日本，然后在世界其他地方。其他國家與地區正跟隨宮脅的腳步，印度尤其熱衷于此。在孟買，整個城市及其郊區的多個宮脅森林中共有20多萬棵樹。在班加羅爾，這一數量超過了5萬。金奈的一個園工小組已經建造了25個宮脅森林。印度南部蒂魯內爾維利當局使用宮脅造林法在當地學校里建立綠色植被。2020年，海德拉巴開始建造單體最大的微型森林，面積達4公頃。

The method is becoming popular outside Asia， too. In Europe， Belgium， France and the Netherlands are all home to Miyawaki forests. There are also a handful in Latin America. Wherever they are planting， though， gardeners are not constrained to follow natures recipe book to the letter. Miyawaki forests can be customised to local requirements. A popular choice， for example， is to include more fruit trees than a natural forest might support， thus creating an orchard that requires no upkeep.

宮脅造林法在亞洲之外的地方也越來越流行。在歐洲，比利時、法國和荷蘭都有宮脅森林。拉丁美洲也有幾個。然而，無論在哪里造林，園工們并不嚴格遵循大自然的秘方。宮脅森林可以因地制宜。例如，目前比較流行在宮脅森林中種植高于天然林承載量的果樹，這樣就會得到一個不需要維護的果園。

One such pomologist is Shubhendu Sharma. Mr Sharma has， through Afforestt， a firm he founded in 2011， become a leading proponent of the Miyawaki method. He was once an engineer at Toyotas factory in Bangalore and has brought his experience building cars to bear on4 the question of tree planting. He is particularly hot on5 time and motion6. He has measured how long， on average， it takes to plant each sort of seed or seedling and uses that information to schedule their sowing. Since its foundation， Afforestt has created over a hundred forests in ten countries in this way， and is currently setting up more. It has also spawned at least 15 imitators， in places as disparate as Australia， Chile and Iran.

舒本杜·夏爾馬就是采用這種方法的果樹栽培學家。2011年，夏爾馬成立Afforestt公司，由此成為宮脅造林法的主要支持者。曾在豐田班加羅爾工廠擔任工程師的夏爾馬，將自己制造汽車的經驗運用到植樹造林上。夏爾馬特別擅長設計最佳工作方法。他測量了栽種每種種子或幼苗平均需要多長時間，并利用這一信息來安排何時播種。自成立以來，Afforestt已經以這種方式在10個國家打造了100多個森林，目前還在建造更多的森林。Afforestt還孵化出了至少15個模仿其模式的公司，分布在澳大利亞、智利、伊朗等不同的地方。

Heres one I prepared earlier

準備已久

Mr Sharmas epiphany came one day in 2009， when Dr Miyawaki arrived at his workplace to plant a forest there. He was so impressed by this that he decided to transform his own backyard in like manner， with a planting that featured especially guava trees. Once the trees were established， Mr Sharma found that the temperature under his trees was 5°C below that of the surrounding area. As to guava， the forest grew so many of them that his mother had to give them away to neighbours.

夏爾馬的頓悟發生在2009年的一天，當時宮脅博士來到夏爾馬工作的地方，在那兒種下了一個森林。夏爾馬對此印象深刻，于是決定以同樣的方式改造自己的后院，主要種植番石榴樹。番石榴樹種下后，夏爾馬發現樹下溫度比周邊低了5℃。至于番石榴，由于后院森林里結了太多果，夏爾馬的母親不得不把它們送給鄰居。

What Mr Sharma and others like him offer looks like a modern version of the 19th-century movements7 that brought city parks and their associated health benefits to the industrialising West. In those days the prevailing attitude towards nature was to try to tame it， and the parks created reflect that in their controlled， formal design. Now， greenery and environmentalism are the fashion， and the quasi-wild Miyawaki approach reflects this to a T8. The purpose is the same as before—to introduce rus in urbe9. But the means are completely in tune with the times.

夏爾馬和其他志同道合之人所從事的似乎是19世紀城市美化運動的現代版本。當時的運動把城市公園以及與其相關的健康福利帶到了正在工業化的西方。在那個時代，人們對于自然的普遍態度是試圖馴服自然，這種態度在新建公園規規矩矩、整整齊齊的設計中得到了體現?，F在，綠色植物和環保主義成為時尚，宮脅模擬天然林的造林法恰恰說明了這一點。建造微型森林的目的和以前一樣，即打造鬧市中的田園，但手段卻完全與時代并進了。

（譯者為“《英語世界》杯”翻譯大賽獲獎者；單位：滁州職業技術學院）

1生態演替指一定地區內，群落的物種組成、結構及功能隨著時間進程而發生的連續的、單向的、有序的自然演變過程。

2 shoot up迅速長高。? 3 fend for oneself照料自己。

4 bring sth to bear （on sth）對……施加影響。? ?5 be hot on sth善于（做某事）；（對某事）了解很多。? 6 time and motion = time-and-motion study指為估計生產或工作效率而進行的時間與動作研究。? 7指城市美化運動（city beautiful movement）。19世紀末20世紀初，由美國知識分子、商人、建筑師發起并實踐的，致力于改善基礎設施、美化城市面貌的城市改革運動。

8 to a T〈習語〉（用以表示完全合適）恰好，絲毫不差。? 9 rus in urbe〈拉丁語〉城鎮中的鄉村。