凋落物叶和土壤浸提液对红松种子萌发及 幼苗生长的影响

选择黑龙江凉水国家级自然保护区红松人工林、椴树红松混交林和枫桦红松混交林3种林型,分别采集红松、椴树、枫桦林地上当年凋落的枯叶及其枝条上当年生的鲜叶以及0～10 cm土样,将处理过的4种不同浓度梯度(质量(g)体积(mL)比分别为1:10、1:30、1:50、1:100)浸提液和灭菌蒸馏水(对照)5种处理共10种类型的溶液等量加入放有经催芽、消毒、冲洗的红松种子的培养皿和栽植有红松幼苗的试验盆内,分别进行发芽和盆栽试验,测定其种子的发芽率、发芽势、胚轴和胚根长度以及苗高、根系总长和干质量等7个指标。结果表明:各林型不同浓度土壤浸提液(椴树红松混交林及枫桦红松混交林1:100除外)大多抑制红松种子的萌发,种子平均发芽率大小排序依次为对照(47%)>椴树红松混交林(44%)>枫桦红松混交林(42%)>红松人工林(33%); 各林型高浓度(1:10)浸提液对以上7个测定指标均有抑制作用,且红松人工林土壤浸提液对它们的抑制作用最强,分别较对照显著降低55.32%、51.35%、54.07%、55.51%、15.93%、58.01%、35.71%(P<0.05); 随着浓度的降低,抑制作用减弱,甚至消失或者转变为促进作用。低浓度(1:100)椴树枯叶浸提液对除苗高外的其他6个指标的促进作用最强,依次较对照显著提高38.30%、37.84%、31.10%、25.94%、61.34%、21.43%(P<0.05); 低浓度(1:100)椴树鲜叶浸提液对苗高的促进作用最强,较对照显著提高15.13%(P<0.05)。

Influence of leaf litter and soil leaching liquor on seed germination and seedling growth of Pinus koraiensis

The current fallen leaves from Pinus koraiensis, Tilia amurensis and Betula costata, and their fresh leaves, 0-10 cm soil samples were collected from the P. koraiensis plantation, T. amurensis-P. koraiensis and B. costata-P. koraiensis mixed forests in Liangshui National Nature Reserve in Heilongjiang Province. After the leaves and soil samplings were air dried, smashed(ground), sieved, soaked and filtered, ten types of solutions, including five treatments of leaching liquors with 4 different concentration gradients(1:10, 1:30, 1:50, 1:100)and sterilized distilled water(CK), were equivalently put into culture dishes containing pregerminated, sterilized, and washed P. koraiensis seeds and experimental pots with P. koraiensis seedlings. The germination test and pot experiment were performed respectively to measure the 7 indices including germination percentage, germination potential, hypocotyl and radicle length, seedling height, root length and dry mass. The results showed that the different concentration leaching liquors inhibited the germination of P. koraiensis seeds for all forest types except 1:100 concentration for T. amurensis-P. koraiensis and B. costata-P. koraiensis mixed forests, their mean germination percentage successively ranked in the CK(47%)>T. amurensis-P. koraiensis mixed forest(44%)>B. costata-P. koraiensis mixed forest(42%)>P. koraiensis plantation(33%). High concentration(1:10)leaching liquor had suppressive effects on the 7 measured indices mentioned above, and the strongest suppressive effect was caused by the soil leaching liquor in P. koraiensis plantation, they significantly decreased by 55.32%, 51.35%, 54.07%, 55.51%, 15.93%, 58.01%, 35.71%(P<0.05)as compared with the CK, respectively. The suppressive effects of leaching liquor became weak with its decreasing concentration, it would disappear at a certain concentration or turned into promoting effects. The strongest promoting effects on the other 6 indices except for the seedling height resulted from low concentration(1:100)leaching liquor of T. amurensis fallen leaves, they significantly increased by 38.30%, 37.84%, 31.10%, 25.94%, 61.34%, 21.43%(P<0.05)in comparison with the CK, respectively. The strongest promoting effects on the seedling height came from low concentration(1:100)leaching liquor of T. amurensis fresh leaves, it was significantly raised by 15.13%(P<0.05)compared by the CK.