稀有蝴蝶屢被毁家

【明報專訊】香港擁有240種蝴蝶，但不少蝴蝶的棲息地，並非理想安樂窩。綠色力量發現，近日接連有稀有蝴蝶的棲息地遭破壞，當中位於荃灣川龍路旁一幅面積僅如籃球場的草地，大片植物出現不正常枯萎，懷疑有人施以除草劑，令大量植物及稀有的苧麻珍蝶蟲蛹及成蟲死亡。
綠色力量行政總幹事文志森表示，02年本港首次發現苧麻珍蝶，之後每年3、4月起便會在荃灣川龍一幅草地發現牠們的蹤影，由幼蟲一直生長至成蟲，是該種蝴蝶的重要棲息地。他上月底曾兩度到該處拍攝，首次拍攝時並無異樣，但事隔兩三日，第二次到上址時發現大片植物苧麻出現不正常枯萎，由於該處附近沒有燒焦痕迹，他估計有人曾噴灑除草劑，令植物在短時間內枯萎。
苧麻珍蝶棲息地疑被噴除草劑
他說，川龍是全港唯一有苧麻珍蝶繁殖的地點，事發前粗略統計該處約有50多隻苧麻珍蝶及不少蟲蛹，事後只剩下約10多隻苧麻珍蝶在小部分未枯萎的苧麻之間飛舞，蟲蛹則僅餘一兩個，相信對該群落的苧麻珍蝶造成極大打擊，擔心從此絕迹本港。目前全中國只錄得兩種珍蝶科蝴蝶，苧麻珍蝶是其中一種。
另外，新界西唯一的蝴蝶熱點龍鼓灘，近南朗一幅面積相等於一個籃球場的蕉林內，大量植物遭砍伐，包括蝴蝶的「美食」鬼針草及馬纓丹等，令棲息該處的紅鋸蛺蝶數目大減。龍鼓灘孕育最少116種蝴蝶，是大埔鳳園以外，本港錄得最多蝴蝶的地點之一。紅鋸蛺蝶只在本港數個地點出沒，但以龍鼓灘的群落最穩定。
文志森說，本港觀賞蝴蝶的熱點雖然有40多個，遍佈港九、新界及離島，當中約四分之三因處於郊野公園外，未有受到適當保護，部分地點的環境更非常惡劣，例如苧麻珍蝶的聚居地川龍，竟然是行車路旁的一片草地。
他未能確定兩處地點是否遭人惡意破壞，但指事件反映政府的保育政策被動，以致具保育價值的土地面對被破壞的危機，「以川龍為例，噴除草劑的人未必有惡意，結果卻殺死了大量稀有蝴蝶，如果政府主動保育這些土地，相信不會發生以上事件」。

Organic food 'better' for heart

organic fruit and vegetables may be better for you than conventionally grown crops, US research suggests.

A ten-year study comparing organic tomatoes with standard produce found almost double the level of flavonoids - a type of antioxidant.

Flavonoids have been shown to reduce high blood pressure, lowering the risk of heart disease and stroke.

Writing in the Journal of Agricultural and Food Chemistry, the team said nitrogen in the soil may be the key.

Dr Alyson Mitchell, a food chemist at the University of California, and colleagues measured the amount of two flavonoids - quercetin and kaempferol - in dried tomato samples that had been collected as part of a long-term study on agricultural methods.

These findings also confirm recent European research, which showed that organic tomatoes, peaches and processed apples all have higher nutritional quality than non-organic Peter Melchett, Soil Association

They found that on average they were 79% and 97% higher respectively in the organic tomatoes than in the conventionally grown fruit.

New Scientist magazine reported that the different levels of flavonoids in tomatoes are probably due to the absence of fertilisers in organic farming.

Flavonoids are produced as a defence mechanism that can be triggered by nutrient deficiency, such as a lack of nitrogen in the soil.

The inorganic nitrogen in conventional fertiliser is easily available to plants and so, the researchers suggests, the lower levels of flavonoids are probably caused by over-fertilisation.

Conflicting evidence

Flavonoids have also been linked with reduced rates of some types of cancer and dementia.

The Food Standards Agency says there is some evidence that flavonoids can help to reduce the risk of cardiovascular disease and they are currently carrying out a study to look at the health benefits in more detail.

However, a spokesperson said there was no evidence that organic food was healthier.

"Our long-standing advice on organic food is there can be some nutrient differences but it doesn't mean it's necessarily better for you."

For example, a recent study found that organic milk had higher levels of omega-3 fatty acids, but the FSA points out that these short-chain fatty acids do not seem to have the health promoting benefits offered by long-chain omega-3 oils found in oily fish.

Peter Melchett, Soil Association policy director said: "We welcome the now rapidly growing body of evidence which shows significant differences between the nutritional composition of organic and non-organic food.

"This is the second recent American study to find significant differences between organic and non-organic fruit.

"These findings also confirm recent European research, which showed that organic tomatoes, peaches and processed apples all have higher nutritional quality than non-organic."

"As further scientific evidence emerges from new research looking at differences between organic and non-organic food, the Soil Association will be asking the FSA to keep their nutritional advice to consumers under review."

九龍醫院太陽能發電

【明報專訊】九龍醫院與機電工程署及中華電力合作，在醫院康復大樓天台安裝太陽能光伏板系統，面積有200至300平方呎，利用太陽能發電，提供9千瓦電力，可為兩間病房提供冷氣通風所需。

中電撥款90萬興建

機電署衛生工程部衛生工程經理蔡國權指出，這個太陽能發電系統的省電效果有限，但希望藉此增加市民對可再生能源的認識，期望未來技術有更好發展，增加成本效益，讓再生能源更普及。

該太陽能系統耗資90萬元，由中電創新能源基金撥款興建，歷時半年。系統接駁至中電供電網，為康復大樓主電力供應的一部分。中電輸電及供電業務部總監潘偉賢表示，發展可再生能源供電系統需要大量地方，集團期望透過發展大量小型供電設施達到集腋成裘的效果。

九龍醫院將於西翼展開第二期工程，落成後可望提供比第一期高3倍的電力。機電署表示，現時全港的太陽能光伏板系統共提供700千瓦電力。