贺兰山东麓典型葡萄园土壤有机碳库组成及其活跃度

[目的]研究贺兰山东麓典型葡萄园土壤有机碳库的组成及其活跃度,量化该区域葡萄园生态系统潜在的固碳能力,为挖掘葡萄园碳汇能力和核算碳汇价值提供科学依据。[方法]以贺兰山东麓典型的新慧彬葡萄园为例,开展园区尺度的土壤有机碳取样调查与分析,研究土壤有机碳含量、密度和组分等特征。[结果](1)葡萄园0—100 cm剖面土壤有机碳平均含量为4.65 g/kg,土壤有机碳密度为64.5 t/hm^(2),虽然土壤有机质含量低,养分匮乏,但依然是葡萄园生态系统碳库的主要部分。(2)在垂直剖面上,土壤有机碳含量随着土层加深而递减,且0—40 cm表层和40—100 cm深层的土壤有机碳含量存在显著差异,表层土壤的有机碳富集系数大于1,对有机碳具有更强的固持能力。(3)土壤有机碳含量在园区范围内存在空间异质性,其中表层土壤有机碳的空间异质性受制于不同田块间葡萄品种及施肥等垦殖活动差异,而深层土壤有机碳的空间异质性主要受制于原始土壤的形成背景。(4)土壤有机碳活性、中性和惰性组分的比例约为1∶2∶5。惰性组分比例较高,碳库活度较低,稳定性较强。虽然惰性有机碳含量决定了总有机碳的高低,但中性有机碳含量的变化亦会影响总有机碳和全碳含量。[结论]贺兰山东麓葡萄园土壤碳库活度和有机碳含量水平较低。葡萄种植最终会增加土壤碳储量,增强生态系统的碳汇能力。

西北干旱区绿洲葡萄园净碳交换及其影响因素

研究干旱区绿洲农业生态系统碳收支动态和其碳源汇形成机制对于指导绿洲农业固碳减排至关重要。基于敦煌干旱绿洲葡萄园涡度相关系统观测的CO_(2)通量和相关环境因子数据,估算2019年生长季(5-10月)葡萄园的碳收支总量,同时探究净生态系统碳交换(NEE)的日、季动态及其对叶面积指数(LAI)、光合有效辐射(PAR)、水汽压差(VPD)和空气温度(Ta)等的响应。结果表明:(1)生长季期间,葡萄园净生态系统碳交换(NEE)、生态系统呼吸(Re)和总初级生产力(GPP)的累计量分别为-647.3、883.2 g C·m^(-2)和1530.5 g C·m^(-2),Re/GPP值为57.7%,表明其碳消耗强度较低,为强烈的碳汇过程。(2)生长季NEE量变化呈单峰型(7月峰值),与空气温度的季节变化相似。这表明在水分供应充足的基本条件下,空气温度对于NEE具有显著影响。(3)生长季NEE受到LAI、PAR、VPD、Ta等生物物理因素的综合作用,在整个生长季PAR是与其相关性最高的环境因子,通过驱动光合作用增加固碳量;生长季LAI先增加后减少,光合固碳量也相应受到影响,进而造成NEE呈先下降后上升趋势。同时,保持VPD处于适宜的范围(20~35 hPa),可有效地提高其固碳能力。

Land Suitability of the Different Cultivars in the South Tyrol Wine Region (Italy)

The geology and geomorphology of the territory as well as microclimate are local geographical features that serve as natural ecological resources. These factors influence the biosynthetic activities of plants and their phenology, promoting biodiversity and the qualitative predispositions of grapes and wine. South Tyrol is one of the smallest wine-growing regions in Italy, but owing to its position amid the Alps, it is also one of the most multifaceted, a region of wide geographical diversity and remarkable ecological range, hosting a concentration of many different vine varieties and high quality wines. This applied territorial research investigates the particular environmental circumstances that favour this case. A data set describing approximately 26,000 vineyards and 5450 hectares has been employed to evaluate 18 subzones of wines and vines selected from 86 new geographical units defined within the DOC wine region. A new environmental mapping scheme called VHTG is proposed, based on the ecological indicators of grape variety, altitude, topoclimate and the geopedology of the vineyards. Using the VHTG method analyses, the comparisons between the territories of origin and their vine varieties can be rendered simpler and more direct, and it can distinguish the most suitable ecological conditions of wine production zones. It is now possible to examine more in detail the land suitability of the different cultivars, defined by the use of the ecological indicators summarized in the VHTG method. White grape varieties such as Sylvaner and Veltliner prefer high altitudes between 600 m and 900 m, a very high solar radiation SRI index from 80 to 95, and acidic sandy soils of silicate minerals. The most complete and intense tannic structure of regional Pinot Noir correlates to quite clayey soils with dolomite mineral, slightly alkaline, on vineyards at altitudes between 350 m and 410 m, with rather low SRI index from 60 to 75. Similar geopedological conditions favour Gewürztraminer, which, however, requests SRI from 75 to 85. Merlot and Cabernet vines are best expressed in the hottest regional sub-zones, on moderately clayey subalkaline soils at 250 - 350 m of altitudes and SRI around 80. The indigenous red grape variety Lagrein is mostly localized on alluvial cone at altitudes under 350 m, on soft and ventilated acid sands with volcanic silicate minerals.

葡萄园生态系统碳源/汇及碳减排策略研究进展

葡萄园生态系统是农业生态系统的重要组成部分,集中连片栽培的葡萄园具有重要的生态价值。开展葡萄园生态系统碳源/汇的研究,是完整探讨葡萄园生态系统碳循环必不可少的内容。随着葡萄生态学研究的进一步深入,如何直观地揭示葡萄园生态系统碳循环规律和碳汇功能已经成为葡萄生态学领域关注的热点问题。研究发现,葡萄园生态系统固定大量碳,将碳封存在葡萄果实等一年生器官、主干等多年生器官以及土壤碳库中。葡萄园生态系统碳输入量大于碳输出量,是碳汇;土壤是葡萄园生态系统最大的碳库,占总碳储量的70%,尤其是土藤界面;覆盖和免耕作为葡萄园的碳减排策略,可以减少碳排放,提高葡萄园土壤肥力。基于此,为了阐明葡萄园生态系统的碳汇价值,该文围绕葡萄生态学最新研究进展,系统回顾了葡萄园生态系统中碳循环规律、碳汇研究进展及碳减排策略,为葡萄生态学的研究提供理论基础,并对本领域未来的研究方向和应用前景进行展望。