Question

如圖是一個(gè)森林生態(tài)系統(tǒng)的植被生長情況，其他成分未表示出。有位科學(xué)家研究了圖上的光合作用與光照強(qiáng)度之間的關(guān)系（圖甲），及葉肉細(xì)胞中的相對含水量與光照強(qiáng)度之間的關(guān)系（圖乙）。請據(jù)圖分析回答：

⑴圖甲中的a點(diǎn)（曲線與橫軸交點(diǎn)）表示__________________________________________；b點(diǎn)（曲線與縱軸交點(diǎn)）時(shí)葉肉細(xì)胞產(chǎn)生ATP的細(xì)胞器是：______________。

⑵能夠反映a點(diǎn)時(shí)生理過程及變量關(guān)系的是右上圖中的                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           

⑶測定森林喬木在炎熱夏季一天中的光合作用時(shí)，往往發(fā)現(xiàn)光合作用強(qiáng)度要下降，原因是葉肉細(xì)胞中缺少_______（生理過程）的原料；與森林中人參、三七等植物光合作用相對應(yīng)的是圖甲中的曲線__________。

⑷圖乙中表示喬木葉肉細(xì)胞的相對含水量與光照強(qiáng)度之間關(guān)系的曲線是________。

⑸假設(shè)將圖中部分區(qū)域的喬木用無色細(xì)眼網(wǎng)一棵棵套住，則由于破壞了_________，網(wǎng)內(nèi)喬木將凋亡。一段時(shí)間后，林下的灌木、草本植物也不能生存，其主要影響因素是________________________，試分析其原因________________________________________

Answer 1

⑴此光照強(qiáng)度下，某植物光合作用吸收的CO₂量等于與呼吸作用釋放的CO₂量/此光照強(qiáng)度下，某植物光合作用強(qiáng)度等于呼吸作用強(qiáng)度/此光照強(qiáng)度下，某植物光合速率等于呼吸速率      線粒體；⑵A ；⑶暗反應(yīng)    Ⅲ   ⑷1   ⑸食物鏈    陽光/光照  喬木凋亡后，陽光直射底層，使底層光照過強(qiáng)，耐陰植物因水分蒸騰過快而死亡

解析:

⑴⑵見答案。⑶炎熱夏季中午植物蒸騰作用過強(qiáng)導(dǎo)致保衛(wèi)細(xì)胞由于過渡失水而使植物氣孔關(guān)閉；這樣會造成葉片組織間隙CO₂濃度降低，影響暗反應(yīng)的進(jìn)行。人參、三七等植物屬于陰生植物，適合在弱光環(huán)境條件下生存，對弱光的利用能力強(qiáng)；對強(qiáng)光的利用能力弱。⑷相對于灌木和草本植物來說，喬木根系發(fā)達(dá)，吸水力強(qiáng)，葉片相對含水量受光照強(qiáng)度的影響小。