The effects of external forcing agents on the biodiversity and species richness associated with the environmental history of Louisiana's wetlands over the late Holocene
The effects of external forcing agents on the biodiversity and species richness associated with the environmental history of Louisiana's wetlands over the late Holocene
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DOI：
10.1016/j.quascirev.2022.107865
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发表时间：
2022-11-11
影响因子：
4
通讯作者：
McCloskey，Terrence A.
中科院分区：
文献类型：
--
作者：
Ryu，Junghyung;Liu，Kam-biu;McCloskey，Terrence A.
这项研究评估了美国路易斯安那州东南部小湖附近的植物多样性和物种丰富度水平，并重建了过去 3200 年的环境历史。由于环境条件的变化，从地方（人类活动）、区域（三角洲波瓣转换）到全球（海平面上升），出现了六个连续的生态系统：分流间海湾（3.2-2.3卡吉尔BP）、水生淡水沼泽（2.3-1.42卡吉尔BP）、中生沿海草原（1.42-0.92卡吉尔BP） BP)、香蒲沼泽 (0.92–0.33 cal kyr BP)、中间沼泽 (0.33 cal kyr Bp – ad, 1972 CE)、咸湿沼泽 (197 CE2-现在)。对每个生态系统的生物多样性进行了评估，最大多样性出现在三角洲增长最大时期，因为河流动态通过创造多样化的栖息地（包括沼泽、沼泽、牛轭湖和天然堤坝）增加了景观异质性，而海侵阶段则由于盐度增加而呈现出最低的生物多样性。多变量分析用于识别每个阶段的主要沉积过程并推断最接近的强迫剂。早期的生态系统变化是由三角洲周期的阶段控制的，而最近的变化与人类活动和全球气候变化的影响有关，例如海平面上升和更强烈的热带气旋。
This study evaluates plant diversity and species richness levels and reconstructs the environmental history of a site near Little Lake in southeast Louisiana, USA over the past 3200 years. Six successive ecosystems occurred as a result of changing environmental conditions, ranging from the local (anthropogenic activities), regional (delta lobe switching), and to global (sea level rise): interdistributary bay (3.2–2.3 cal kyr BP), hydrophytic freshwater marsh (2.3–1.42 cal kyr BP), mesophyte coastal prairie (1.42–0.92 cal kyr BP),Typhamarsh (0.92–0.33 cal kyr BP), intermediate marsh (0.33 cal kyr Bp – ad, 1972 CE), brackish marsh (197 CE2-present). Biodiversity was evaluated for each ecosystem, with maximum diversity occurring during the period of maximum delta-growth as the river dynamics increased landscape heterogeneity by creating diverse habitats, including marsh, swamps, oxbow lakes, and natural levees, while the transgressive phase presents the lowest biodiversity due to increasing salinity. Multivariate analysis is used to identify the primary depositional processes for each stage and infer the proximate forcing agents(s). Early ecosystem shifts were controlled by the stages of the delta cycle, while more recent shifts are associated with anthropogenic activities and the effects of global climate change such as sea-level rise, and more intense tropical cyclones.