地理距离和环境因子对阿拉善戈壁植物群落β多样性的影响

doi:10.17520/biods.2022029

摘要/Abstract

摘要：

内蒙古阿拉善地区分布着超过20万km²的典型戈壁生态系统, 且这些戈壁生态系统正遭受着持续性气候变暖与极端天气的影响。然而, 土壤、气候、空间变量等因子对阿拉善戈壁大尺度植物β多样性及其关键组分的相对影响还没有得到系统研究。本文通过对阿拉善典型戈壁生境的276个样方进行植物群落组成调查, 并结合气候、土壤等数据, 探讨了地理距离和环境因子对阿拉善戈壁区植物群落β多样性及其组分的影响。研究表明: (1)在阿拉善戈壁区, 随着地理距离的增加, 植物群落β多样性及物种周转组分显著增加, 而且β多样性主要源于物种周转组分, 物种嵌套组分的贡献非常有限; (2)偏Mantel分析显示环境因子和地理距离对β多样性及其物种周转组分均有显著的单独作用; 方差分解结果进一步表明, 环境因子和地理距离共同解释了植物β多样性及其物种周转组分10.84%-17.67% (Bray-Curtis)和15.47%-24.81% (Sørensen)的变异, 但环境因子可以单独解释更多的变异(6.62%-9.97% (Bray-Curtis)和8.98%-14.51% (Sørensen))。在众多环境因子中, 气温日较差、土壤含水量和地表砾石盖度对植物群落β多样性和物种周转组分的贡献更大。以上结果表明, 环境过滤、扩散限制以及其他未知过程可能共同影响阿拉善戈壁区植物群落β多样性格局, 其中环境过滤可能具有更大的影响。

关键词: β多样性, 物种周转, 物种嵌套, 环境过滤, 扩散限制

Abstract

Aims: The gobi desert covers over 200,000 km² on the Alxa Plateau in northern China. Due to climate change, the ecosystem is subject to continuous warming and extreme weather events. Yet, the relative impacts of environmental filtering versus dispersal limitations on β diversity and its two components, species turnover and nestedness, in this unique ecosystem are still unclear.

Methods: We selected 276 plant plots in the gobi desert region of Alxa to examine how geographic distance and environmental factors influence β diversity and its two components.

Results: The results showed that: (1) β diversity and species turnover had a significantly linear relationship with geographic distance, and most of the variance in β diversity of the plant community was caused by species turnover and not nestedness. (2) A partial Mantel analysis showed that both environmental distance and geographic distance impacted β diversity and species turnover. Variance partitioning analysis indicated that while environmental distance and geographic distance together explained 10.84%-17.67% and 15.47%-24.81% of the variation in β diversity and species turnover on the Bray-Curtis and Sørensen indices, respectively, environmental distance alone explained 6.62%-9.97% and 8.98%-14.51%. Among all environmental factors, mean diurnal range, soil water content, and surface gravel coverage were the most important variables for explaining β diversity and species turnover.

Conclusion: Our results suggest that while β diversity in the gobi desert region of Alxa is determined by environmental filtering, dispersal limitation, and other unexamined processes together, environmental filtering may have the strongest impacts.

Key words: β diversity, species turnover, species nestedness, environmental filtering, dispersal limitation

曲梦君, 努尔依拉·阿巴拜克, 邹旭阁, 赵航, 朱威霖, 王健铭, 李景文 (2022) 地理距离和环境因子对阿拉善戈壁植物群落β多样性的影响. 生物多样性, 30, 22029. DOI: 10.17520/biods.2022029.

Mengjun Qu, Nueryila·Ababaike , Xuge Zou, Hang Zhao, Weilin Zhu, Jianming Wang, Jingwen Li (2022) Influence of geographic distance and environmental factors on beta diversity of plants in the Alxa gobi region in northern China. Biodiversity Science, 30, 22029. DOI: 10.17520/biods.2022029.

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链接本文: https://www.biodiversity-science.net/CN/10.17520/biods.2022029

https://www.biodiversity-science.net/CN/Y2022/V30/I11/22029

图/表 6

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变量 Variables	范围 Range	平均值 Mean	标准差 SD
经度 Longitude	98.06°-106.33° E	102.82	2.38
纬度 Latitude	37.47°-42.49° N	40.54	1.36
海拔 Altitude (m)	855.00-1,937.67	1,228.55	245.82
土壤含水量 Soil water content (%)	0.05-7.87	1.93	1.79
土壤全氮 Soil total nitrogen (mg/g)	0.06-1.47	0.34	0.24
土壤有机碳 Soil organic carbon (mg/g)	0.99-12.46	4.02	2.13
土壤pH值 Soil pH value	7.65-9.55	8.45	0.42
地表砾石盖度 Surface gravel coverage (%)	0.00-0.95	0.46	0.26
年均温 Mean annual temperature (℃)	5.18-9.14	7.85	1.07
最冷月均温 Mean temperature of coldest month (℃)	-12.40 to -7.60	-10.29	1.12
最热月均温 Mean temperature of warmest month (℃)	20.00-26.50	24.00	1.57
气温日较差 Mean diurnal range (℃)	12.80-15.00	14.32	0.57
气温年较差 Temperature annual range (℃)	42.90-51.50	48.18	2.11
年降水量 Annual precipitation (mm)	29.00-223.00	90.20	53.73
湿润指数 Moisture index	-97.48 to -75.73	-91.57	5.18
实际蒸散量 Actual evapotranspiration (mm)	32.00-202.00	86.14	45.67
潜在蒸散量 Potential evapotranspiration (mm)	919.00-1,157.00	1,086.26	54.99

变量 Variables	范围 Range	平均值 Mean	标准差 SD
经度 Longitude	98.06°-106.33° E	102.82	2.38
纬度 Latitude	37.47°-42.49° N	40.54	1.36
海拔 Altitude (m)	855.00-1,937.67	1,228.55	245.82
土壤含水量 Soil water content (%)	0.05-7.87	1.93	1.79
土壤全氮 Soil total nitrogen (mg/g)	0.06-1.47	0.34	0.24
土壤有机碳 Soil organic carbon (mg/g)	0.99-12.46	4.02	2.13
土壤pH值 Soil pH value	7.65-9.55	8.45	0.42
地表砾石盖度 Surface gravel coverage (%)	0.00-0.95	0.46	0.26
年均温 Mean annual temperature (℃)	5.18-9.14	7.85	1.07
最冷月均温 Mean temperature of coldest month (℃)	-12.40 to -7.60	-10.29	1.12
最热月均温 Mean temperature of warmest month (℃)	20.00-26.50	24.00	1.57
气温日较差 Mean diurnal range (℃)	12.80-15.00	14.32	0.57
气温年较差 Temperature annual range (℃)	42.90-51.50	48.18	2.11
年降水量 Annual precipitation (mm)	29.00-223.00	90.20	53.73
湿润指数 Moisture index	-97.48 to -75.73	-91.57	5.18
实际蒸散量 Actual evapotranspiration (mm)	32.00-202.00	86.14	45.67
潜在蒸散量 Potential evapotranspiration (mm)	919.00-1,157.00	1,086.26	54.99

影响因素 Variables	控制因素 Control variables	Bray-Curtis			S?rensen
影响因素 Variables	控制因素 Control variables	总体 Total	周转 Turnover	嵌套 Nestedness	总体 Total	周转 Turnover	嵌套 Nestedness
环境距离 Environmental distance	-	0.3063^**	0.2790^**	-0.2198	0.3715^**	0.3052^**	-0.1239
地理距离 Geographic distance	-	0.2461^**	0.2006^**	-0.1110	0.2706^**	0.2427^**	-0.1333
环境距离 Environmental distance	地理距离 Geographic distance	0.2251^**	0.2151^**	-0.1913	0.2896^**	0.2254^**	-0.0717
地理距离 Geographic distance	环境距离 Environmental distance	0.1257^**	0.0860^*	-0.0125	0.1226^**	0.1222^**	-0.0870

影响因素 Variables	控制因素 Control variables	Bray-Curtis			S?rensen
影响因素 Variables	控制因素 Control variables	总体 Total	周转 Turnover	嵌套 Nestedness	总体 Total	周转 Turnover	嵌套 Nestedness
环境距离 Environmental distance	-	0.3063^**	0.2790^**	-0.2198	0.3715^**	0.3052^**	-0.1239
地理距离 Geographic distance	-	0.2461^**	0.2006^**	-0.1110	0.2706^**	0.2427^**	-0.1333
环境距离 Environmental distance	地理距离 Geographic distance	0.2251^**	0.2151^**	-0.1913	0.2896^**	0.2254^**	-0.0717
地理距离 Geographic distance	环境距离 Environmental distance	0.1257^**	0.0860^*	-0.0125	0.1226^**	0.1222^**	-0.0870

	Bray-Curtis指数 Bray-Curtis index		S?rensen指数 S?rensen index
	R²= 0.167	R²= 0.099	R²= 0.236	R²= 0.138
	总体 Total	周转 Turnover	总体 Total	周转 Turnover
ln(地理距离) ln(Geographic distance)	4.60	2.98	8.19	5.32
海拔 Altitude	2.16	-	4.35	-
土壤含水量 Soil water content	2.21	1.55	3.56	2.21
土壤全氮 Soil total nitrogen	-	-	-	-
土壤有机碳 Soil organic carbon	-	-	-	-
土壤pH值 Soil pH value	1.59	-	-	-
地表砾石盖度 Surface gravel coverage	1.96	1.20	2.57	1.85
年均温 Mean annual temperature	1.85	1.89	-	-
最冷月均温 Mean temperature of coldest month	-	-	-	-
气温日较差 Mean diurnal range	2.33	2.31	4.93	4.43
气温年较差 Temperature annual range	-	-	-	-