Page 53 - 《广西植物》2023年第9期
P. 53
9 期 包明慧等: 千岛湖片段化生境中木本植物种子雨基本特征及其影响因子 1 6 0 1
Abstract: Seed rain can affect species compositionꎬ forest community diversityꎬ and plant population and community
renewal. Studying the characteristics of seed rain is of great significance for in ̄depth research on regeneration strategies
and restoration of plant population. In order to explore the basic characteristics of seed rain in fragmented habitatsꎬ this
study used monthly seed rain data collected from 2015 to 2020ꎬ and used the Kruskal ̄Wallis test to analyze the annual
difference of the seed rain density of woody plantꎬ and to analyze the monthly difference of the seed rain density of
species with different dispersal syndromes. Then we used linear mixed ̄effect models to test the relationships among island
spatial attributes (i. e.ꎬ island areaꎬ the distance to the mainlandꎬ and the distance to the nearest island)ꎬ climatic
factors (i. e.ꎬ accumulated temperature above 0 degreesꎬ precipitation) and seed rain density of woody plant and species
with different dispersal syndromes. The results were as follows: (1) During the six years of 2015- 2020ꎬ a total of
877 178 mature seeds of woody plant were collected from 240 seed traps in 29 study islandsꎬ belonging to 26 familiesꎬ 40
genera and 52 species. (2) Zoochory was the major dispersal syndrome in the Thousand Island Lakeꎬ there were great
differences in the temporal dynamics of seed rain in different dispersal syndromes. (3) The annual density of seed rain of
woody plant was significantly positively correlated with island area and annual accumulated temperatureꎬ and
significantly negatively correlated with annual precipitation. (4) The monthly density of seed rain of autochory was
significantly positively correlated with the distance to the nearest islandꎬ while that of zoochory was significantly
positively correlated with the distance to the mainlandꎬ and that of anemochory was significantly positively correlated with
the monthly accumulated temperature. In conclusionꎬ habitat fragmentation affect the temporal dynamics of the seed rain
of woody plant through island spatial attributes.
Key words: seed rainꎬ dispersal syndromeꎬ habitat fragmentationꎬ temporal dynamicꎬ woody plant
种子雨是指种子植物的种子或果实从母树向 (郭华仁ꎬ2019)ꎮ 种子雨的季节性动态由不同的
地表散落的过程(杜彦君和马克平ꎬ2012a)ꎮ 种子 种子传播策略驱动(Li et al.ꎬ 2012)ꎮ 风力传播的
雨是森林种群和群落更新的关键因子之一( Perini 物种倾向于在干季果实成熟传播ꎬ动物传播的物
et al.ꎬ 2019)ꎮ 种子雨的时间动态是种子雨的基 种倾向于在雨季果实成熟传播ꎬ这一结论已在多
本特征之一ꎬ主要表现为群落、种群和个体水平上 项研究中得到验证ꎬ如厄多瓜尔的季节性干旱热
的季节动态和年际变化( 于顺利等ꎬ2007ꎻ Wang et 带森林(Jara ̄Guerrero et al.ꎬ 2020)、巴西卡廷加旱
al.ꎬ 2017)ꎮ 由于种子受环境中生物因子和非生 生热带林(Griz & Machadoꎬ 2001)ꎮ 种子传播对维
物因子的影响ꎬ这些因子包括温度和降水等非生 持种群和群落结构等功能至关重要ꎬ但在片段化
物因子以及物种自身生物学-生态学特征如种子 生境中ꎬ它是被破坏 最 严 重 的 过 程 之 一 ( Burnsꎬ
传播方式等ꎬ因此种子雨可作为种群和群落动态 2005ꎻ McConkey et al.ꎬ 2012ꎻ Emer et al.ꎬ 2018)ꎮ
的指 标 ( Rahbekꎬ 2005ꎻ Barrettꎬ 2013ꎻ Zhang et 生境片段化是指连续的生境被分割成多个相
al.ꎬ 2013)ꎮ del Cacho 等(2013) 发现ꎬ温度升高、 互隔离的小斑块(片段)(Wilcove et al.ꎬ 1986)ꎬ及
年降雨量增加提升了多花欧石楠(Erica multiflora) 其带来的生境面积减小、生境隔离度增加和边缘
的种 子 雨 产 量ꎮ Muller ̄Landau 等 ( 2008) 对 BCI 效应增强等过程( Fischerꎬ 2006)ꎮ 生境片段化通
(Barro Colorado Island) 50 hm 森林动态监测样地 常会导致生物同质化ꎬ从而导致群落以喜光和耐
2
中 41 个树种的研究发现ꎬ种子传播方式相同的不 旱物种为主( Lobo et al.ꎬ 2011)ꎬ并加剧物种之间
同物种ꎬ其种子越重传播距离越近ꎮ 的 竞 争ꎬ 减 少 了 物 种 多 样 性 ( Bregman et al.ꎬ
种子传播方式可分为自主传播和借物传播ꎮ 2015)ꎮ 此外ꎬ生境片段化还会导致种子传播者的
其中ꎬ借物传播又可分为水力传播、风力传播和动 多度和丰富度的改变ꎬ尤其是大型种子扩散者的
物传播三大类ꎻ自主传播是指种子通过本身的构 减少(Hagen et al.ꎬ 2012)ꎬ破坏了动物对种子的有
造机能ꎬ经由重力、弹跳或旋钻等方式离开母体甚 效传播ꎬ减少了动物传播植物的补员率(Cordeiro &
或入土ꎮ 种子因动物的携带而传播到他处称为动 Howeꎬ 2003ꎻ Lehouck et al.ꎬ 2009)ꎬ并导致植物灭
物传播ꎮ 靠风力传播的传播方式称为风力传播 绝概率最高可达 10 倍(Caughlin et al.ꎬ 2014)ꎮ