Effects of grazing intensity on seed production of Caragana stenophylla along a climatic aridity gradient in the Inner Mongolia Steppe, China
XIE Lina1,2, CHEN Weizhong2, Christopher A GABLER3, HAN Lei2, GUO Hongyu2, CHEN Qing2, MA Chengcang2*, GU Song1*
1 College of Life Sciences, Nankai University, Tianjin 300071, China; 2 Tianjin Key Laboratory of Animal and Plant Resistance, College of Life Sciences, Tianjin Normal University, Tianjin 300387, China; 3 Department of Biology and Biochemistry, University of Houston, Houston 77204, USA
Effects of grazing intensity on seed production of Caragana stenophylla along a climatic aridity gradient in the Inner Mongolia Steppe, China
XIE Lina1,2, CHEN Weizhong2, Christopher A GABLER3, HAN Lei2, GUO Hongyu2, CHEN Qing2, MA Chengcang2*, GU Song1*
1 College of Life Sciences, Nankai University, Tianjin 300071, China; 2 Tianjin Key Laboratory of Animal and Plant Resistance, College of Life Sciences, Tianjin Normal University, Tianjin 300387, China; 3 Department of Biology and Biochemistry, University of Houston, Houston 77204, USA
摘要 As the increases of climatic aridity and grazing intensity, shrubs play an increasingly important role in grassland ecosystem in arid and semi-arid regions, and its abundance also generally increases. However, the effects of climatic aridity and grazing intensity on sexual reproduction of shrubs in grassland remain largely unclear. In order to understand the effects of grazing intensity and climatic drought stress, and their interaction on seed production of shrub species, we examined the seed number, seed weight and seed yield of Caragana stenophylla under three grazing intensities (fenced, mild grazing and severe grazing) across a climatic aridity gradient (semi-arid, arid, very arid and intensively arid zones) in the Inner Mongolia Steppe, northern China during 2012–2013. The seed number, seed weight and seed yield gradually increased from the semi-arid to the very arid zones, but decreased from the very arid to the intensively arid zones in fenced plots. The seed number and seed yield decreased from the semi-arid to the intensively arid zones in mild and severe grazing treatment plots, therefore, grazing enhanced the suppression effect of climatic aridity on seed production of C. stenophylla. The seed number and seed yield gradually decreased as grazing intensity increased. The seed weight was highest in severe grazing plots, followed by the mild grazing plots and then the fenced plots. Precipitation varied interannually during the study period. We observed that the seed number, seed weight and seed yield were lower in the low precipitation year (2013) than in the high precipitation year (2012). As climatic drought stress increased, the negative effects of grazing on seed production of C. stenophylla also gradually increased. Our results indicated that climatic drought stress may contribute to the encroachment of C. stenophylla shrub in arid zones by promoting its seed production. However, grazing had negative effects on sexual reproduction of C. stenophylla, and the combined effects of drought stress and grazing seriously suppressed sexual reproduction of C. stenophylla in the intensively arid zone.
Abstract: As the increases of climatic aridity and grazing intensity, shrubs play an increasingly important role in grassland ecosystem in arid and semi-arid regions, and its abundance also generally increases. However, the effects of climatic aridity and grazing intensity on sexual reproduction of shrubs in grassland remain largely unclear. In order to understand the effects of grazing intensity and climatic drought stress, and their interaction on seed production of shrub species, we examined the seed number, seed weight and seed yield of Caragana stenophylla under three grazing intensities (fenced, mild grazing and severe grazing) across a climatic aridity gradient (semi-arid, arid, very arid and intensively arid zones) in the Inner Mongolia Steppe, northern China during 2012–2013. The seed number, seed weight and seed yield gradually increased from the semi-arid to the very arid zones, but decreased from the very arid to the intensively arid zones in fenced plots. The seed number and seed yield decreased from the semi-arid to the intensively arid zones in mild and severe grazing treatment plots, therefore, grazing enhanced the suppression effect of climatic aridity on seed production of C. stenophylla. The seed number and seed yield gradually decreased as grazing intensity increased. The seed weight was highest in severe grazing plots, followed by the mild grazing plots and then the fenced plots. Precipitation varied interannually during the study period. We observed that the seed number, seed weight and seed yield were lower in the low precipitation year (2013) than in the high precipitation year (2012). As climatic drought stress increased, the negative effects of grazing on seed production of C. stenophylla also gradually increased. Our results indicated that climatic drought stress may contribute to the encroachment of C. stenophylla shrub in arid zones by promoting its seed production. However, grazing had negative effects on sexual reproduction of C. stenophylla, and the combined effects of drought stress and grazing seriously suppressed sexual reproduction of C. stenophylla in the intensively arid zone.
This work was supported by the National Natural Science Foundation of China (31570453, 31170381, 31270502, 31300386), the PhD Candidate Research Innovation Fund of Nankai University and the Doctoral Fund of Tianjin Normal University (52XB1208).
通讯作者:
MA Chengcang, GU Song
E-mail: machengcang@163.com;songgu@nankai.edu.cn
引用本文:
XIE Lina, CHEN Weizhong, Christopher A GABLER, HAN Lei, GUO Hongyu, CHEN Qing, M. Effects of grazing intensity on seed production of Caragana stenophylla along a climatic aridity gradient in the Inner Mongolia Steppe, China[J]. 干旱区科学, 2016, 8(6): 890-898.
XIE Lina, CHEN Weizhong, Christopher A GABLER, HAN Lei, GUO Hongyu, CHEN Qing, MA Chengcang, GU Song. Effects of grazing intensity on seed production of Caragana stenophylla along a climatic aridity gradient in the Inner Mongolia Steppe, China. Journal of Arid Land, 2016, 8(6): 890-898.
Becklin K M, Kirkpatrick H E. 2006. Compensation through rosette formation: the response of scarlet gilia (Ipomopsis aggregata: Polemoniaceae) to mammalian herbivory. Canadian Journal of Botany, 84(8): 1298–1303. Bråthen K A, Junttila O. 2006. Infertile times: response to damage in genets of the clonal sedge Carex bigelowii. Plant Ecology, 187(1): 83–95. Cerda N V, Tadey M, Farji-Brener A G, et al. 2012. Effects of leaf-cutting ant refuse on native plant performance under two levels of grazing intensity in the Monte Desert of Argentina. Applied Vegetation Science, 15(4): 479–487. Chen Z Z, Wang S P. 2000. Chinese Typical Grassland Ecosystem. Beijing: Science Press, 106–109. (in Chinese) Del Pozo A, Ovalle C, Aronson J, et al. 2002. Ecotypic differentiation in Medicago polymorpha L. along an environmental gradient in central Chile. I. Phenology, biomass production and reproductive patterns. Plant Ecology, 159(2): 119–130. Fang X W, Turner N C, Yan G J, et al. 2010. Flower numbers, pod production, pollen viability, and pistil function are reduced and flower and pod abortion increased in chickpea (Cicer arietinum L.) under terminal drought. Journal of Experimental Botany, 61(2): 335–345. Harel D, Holzapfel C, Sternberg M. 2011. Seed mass and dormancy of annual plant populations and communities decreases with aridity and rainfall predictability. Basic and Applied Ecology, 12(8): 674–684. Hayes C L, Talbot W A, Wolf B O. 2013. Woodrat herbivory influences saguaro (Carnegiea gigantea) reproductive output. Journal of Arid Environments, 89: 110–115. Hickman K R, Hartnett D C. 2002. Effects of grazing intensity on growth, reproduction, and abundance of three palatable forbs in Kansas tallgrass prairie. Plant Ecology, 159(1): 23–33. Hunt L P. 2001. Low seed availability may limit recruitment in grazed Atriplex vesicaria and contribute to its local extinction. Plant Ecology, 157(1): 53–67. Lebrija-Trejos E, Lobato M C C, Sternberg M. 2011. Reproductive traits and seed dynamics at two environmentally contrasting annual plant communities: From fieldwork to theoretical expectations. Israel Journal of Ecology & Evolution, 57(1–2): 73–90. Li S G, Harazono Y, Oikawa T, et al. 2000. Grassland desertification by grazing and the resulting micrometeorological changes in Inner Mongolia. Agricultural and Forest Meteorology, 102(2–3): 125–137. Liu D, An S Z, Kong Q G, et al. 2010. Population characters of Ligularia narynensis in Kalajun rangeland. Pratacultural Science, 27(4): 25–29. (in Chinese) Ma C C, Gao Y B, Jiang F Q, et al. 2004a. The comparison studies of ecological and water regulation characteristics of Caragana microphylla and Caragana stenophylla. Acta Ecologica Sinica, 24(7): 1442–1451. (in Chinese) Ma C C, Gao Y B, Wang J L, et al. 2004b. The comparison studies of photosynthetic characteristics and protective enzymes of Caragana microphylla and Caragana stenophylla. Acta Ecologica Sinica, 24(8): 1594–1601. (in Chinese) Ma C C, Gao Y B, Guo H Y, et al. 2008. Physiological adaptations of four dominant Caragana species in the desert region of the Inner Mongolia Plateau. Journal of Arid Environments, 72(3): 247–254. Ma C C, Zhang J H, Guo H Y, et al. 2013. Alterations in canopy size and reproduction of Caragana stenophylla along a climate gradient on the Inner Mongolian Plateau. Flora-Morphology, Distribution, Functional Ecology of Plants, 208(2): 97–103. Ma C C, Guo H Y, Wu J B, et al. 2014. Acclimation of photosynthetic traits of Caragana species to desert environment in Inner Mongolian Plateau. Arid Land Research and Management, 28(1): 87–101. May F, Giladi I, Ristow M, et al. 2013. Plant functional traits and community assembly along interacting gradients of productivity and fragmentation. Perspectives in Plant Ecology, Evolution and Systematics, 15(6): 304–318. Meng M, Ni J, Zhang Z G. 2004. Aridity index and its applications in geo-ecological study. Acta Phytoecologica Sinica, 28(6): 853–861. (in Chinese) Peco B, Borghi C E, Malo J E, et al. 2011. Effects of bark damage by feral herbivores on columnar cactus Echinopsis (=Trichocereus) terscheckii reproductive output. Journal of Arid Environments, 75(11): 981–985. Perevolotsky A, Schwartz-Tzachor R, Yonathan R, et al. 2011. Geophytes-herbivore interactions: reproduction and population dynamics of Anemone coronaria L. Plant Ecology, 212(4): 563–571. Piqueras J. 1999. Herbivory and ramet performance in the clonal herb Trientalis europaea L. Journal of Ecology, 87(3): 450–460. Romo-Campos L, Flores-Flores J L, Flores J, et al. 2010. Seed germination of Opuntia species from an aridity gradient in Central Mexico. Journal of the Professional Association for Cactus Development, 12(2): 181–198. Silva H A D, de Moraes A, Carvalho P C D F, et al. 2012. Maize and soybeans production in integrated system under no-tillage with different pasture combinations and animal categories. Revista Ciência Agronômica, 43(4): 757–765. Volis S, Mendlinger S, Ward D. 2002. Differentiation in populations of Hordeum spontaneum along a gradient of environmental productivity and predictability: life history and local adaptation. Biological Journal of the Linnean Society, 77(4): 479–490. Volis S, Mendlinger S, Ward D. 2004. Demography and role of the seed bank in Mediterranean and desert populations of wild barley. Basic and Applied Ecology, 5(1): 53–64. Volis S. 2007. Correlated patterns of variation in phenology and seed production in populations of two annual grasses along an aridity gradient. Evolutionary Ecology, 21(3): 381–393. Wan H W, Bai Y F, Schönbach P, et al. 2011. Effects of grazing management system on plant community structure and functioning in a semiarid steppe: scaling from species to community. Plant and Soil, 340(1–2): 215–226. Wang R Z, Gao Q, Chen Q S. 2003. Effects of climatic change on biomass and biomass allocation in Leymus chinensis (Poaceae) along the North-east China Transect (NECT). Journal of Arid Environments, 54(4): 653–665. Wang R Z, Gao Q. 2003. Climate-driven changes in shoot density and shoot biomass in Leymus chinensis (Poaceae) on the North-east China Transect (NECT). Global Ecology and Biogeography, 12(3): 249–259. Wang R Z, Gao Q. 2004. Morphological responses of Leymus chinensis (Poaceae) to the large-scale climatic gradient along the North-east China Transect (NECT). Diversity and Distributions, 10(1): 65–73. Wang Y T, Deng B, Wang K, et al. 2011. Responses of plant morphology and seed quality to long-term overgrazing in Leymus chinensis. African Journal of Biotechnology, 10(80): 18403–18408. Xie L N, Ma C C, Guo H Y, et al. 2014. Distribution pattern of Caragana species under the influence of climate gradient in the Inner Mongolia region, China. Journal of Arid Land, 6(3): 311–323. Xie L N, Guo H Y, Gabler C A, et al. 2015. Changes in spatial patterns of Caragana stenophylla along a climatic drought gradient on the Inner Mongolian Plateau. PLoS ONE, 10(3): e0121234, doi:10.1371/journal.pone.0121234. Xiong X G, Han X G, Chen Q S, et al. 2003. Increased abundance of woody plants in grasslands and savannas. Acta Ecologica Sinica, 23(11): 2436–2443. (in Chinese) Yang M H, Guo Z D, Wang C G. 1987. Remote sensing explains about Inner Mongolia Municipality climate types. In: Chen K, Li B. Application Study on Remote Sensing in Inner Mongolia Pasture Resource. Hohhot: Inner Mongolia University Press, 46–58. (in Chinese) Zhang J H, Ma C C, Liu Z H, et al. 2011. Expansion strategies of Caragana stenophylla in the arid desert region. Acta Ecology Sinica, 31(8): 2132–2138. (in Chinese) Zhang M L, Huang Y M, Kang Y, et al. 2002. Floristics and vegetation of the genus Caragana in Ordos Plateau. Bulletin of Botanical Research, 22(4): 497–502. (in Chinese) Zhou H Y, Li X R, Fan H W, et al. 2005. Physiological characteristics of several Caragana shrub species under extreme conditions. Journal of Desert Research, 25(2): 182–190. (in Chinese)
2016, Vol. 8 
