Livestock effect on pollination levels in native plant species of the Patagonian Monte desert

Authors

  • Mariana Tadey Laboratorio Ecotono, CRUB-Universidad Nacional del Comahue, S. C. Bariloche, Argentina.

Keywords:

indirect effects, plant-pollinators interaction, pollen tubes, stocking densities

Abstract

Livestock may indirectly affect plant pollination levels through changes in both plants and pollinators’ assemblages. I studied the effect of livestock on the pollination level, estimated as the number of pollen tubes/style, on five frequent species of the Patagonian Monte desert (Atriplex lampa, Gutierrezia solbrigii, Larrea cuneifolia, L. divaricata, Monttea aphylla). In seven paddocks that share similar habitat characteristics but with different stocking rates, I counted pollen tubes per style of each species studied during four consecutive years. In general, pollination levels are affected more by variation between years than by stocking rates. Only two of the five focal species showed changes in their pollination levels (e.g., pollen tubes/style) associated with changes in stocking rates. Likewise, livestock did not affect the frequency of pollinator visits but affected cover of two of the studied species. The changes in cover (caused or not by livestock) affected directly and indirectly (e.g., through modification in pollinator visits frequency) pollination levels. Results from the regressions and path analyses were consistent in relation to which species were more affected by livestock (e.g., Gutierrezia solbrigii y Monttea aphylla). Additional information about pollen quality and nutritional plant resources would be necessary to better understand livestock indirect effects on pollination level.

References

AGUILAR, R. 2005. Efectos de la fragmentación de hábitat sobre el éxito reproductivo de especies nativas del bosque chaqueño serrano de Córdoba. Tesis doctorado. Universidad nacional de Córdoba, Córdoba.

AIZEN, MA & P FEINSINGER. 1994a. Habitat fragmentation, native insect pollinators, and feral honey bees in Argentine Chaco Serrano. Ecological Applications 4:378-392.

AIZEN, MA & P FEINSINGER. 1994b. Forest fragmentation, pollination, and plant reproduction in a Chaco dry forest, Argentine. Ecology 75:330-351.

AIZEN, MA & P FEINSINGER. 2003. Bees not to be? Responses of insect pollinator faunas and flower pollination to habitat fragmentation. Pages 111-129 en G Bradshaw, P Marquet, y H Moonet, editores. How Landscapes Change: Human Disturbance and Ecosystems Disruptions in the Americas. Springer- Verlag Berlin Heidelberg.

AIZEN, MA & DP VÁZQUEZ. 2006. Flower performance in human-altered habitats.en LD Harder, & SCH Barrett, editores. Ecology and Evolution of flowers. Oxford University Press.

BARRETT, SCH & LD HARDER. 1996. Ecology of sexual systems of plant mating. Trends in Ecology and Evolution 11:73-79.

BOND, WJ. 1994. Do mutualisms matter? Assessing the impact of pollinator and disperser disruption on plant extintion. Philosophical Transactions of the Royal Society of London: Biological Sciences 344:83-90.

BOYER, JS. 1988. Cell enlargement and growth- induced water potentials. Physiologia Plantarum 73:311-316.

CABRERA, A. 1953. Esquema fitogeográfico de la República Argentina. Revista del Museo de La Plata, Botánica 8:87-168.

CINGOLANI, AM; I NOY-MEIR & S DÍAZ. 2005. Grazing effects on rangeland diversity: a synthesis of contemporary models. Ecological Applications 15:757-773.

DAFNI, A. 1992. Pollination Ecology. Oxford University Press Inc., New York.

DEL VALLE, HF. 1998. Patagonian soils: a regional synthesis. Ecologia Austral 8:103-123.

DIGGLE, PK. 1992. Development and evolution of plant reproductive characters. Pag. 397 en R Wyatt, editor. Ecology and evolution of plant reproduction. Chapman & Hall, New York.

HARDER, LD. 1988. Choice of individual flowers by bumble bees: interaction of morphology, time and energy. Behaviour 104:60-77.

HARDER, LD & SCH BARRETT. 1996. Pollen dispersal and mating patterns in animal-pollinated plants. Pag. 409 en DG Lloyd, & SCH Barrett, editores. Floral Biology. Studies on floral evolution in animal- pollinated plants. Chapman & Hall, New York.

HERRERA, CM. 1987. Composes of pollinator “quality”: comparative analysis of a diverse insect assemblage. Oikos 50:79-90.

HERRERA, CM. 1989. Pollinator abundance, morphology, and flower visitation rate: analysis of the “quantity” component in a plant-pollinator system. Oecologia 80:241-248.

HERRERA, CM. 2000. Flower-to-seedling consequences of different pollination regimes in an insect-pollinated shrub. Ecology 81:15-29.

HURLBERT, SH. 1984. Pseudoreplication and the design of ecological field experiments. Ecological Monographs 54:187-211.

JORDANO, P; J BASCOMPTE & JM OLESEN. 2003. Invariant properties in coevolutionary networks of plant-animal interactions. Ecology Letters 6:69-81.

KANDORI, I. 2002. Diverse visitors with various pollinator importance and temporal change in the important pollinators of Geranium thunbergii (Geraniaceae). Ecological Research 17:283-294.

KEARNS, CA & DW INOUYE. 1993. Techniques for pollination biologists. University Press of Colorado, Niwot, Colorado.

KEARNS, CA & DW INOUYE. 1997. Pollinators, flowering plants, and conservation biology. Bioscience 47:297-306.

KLEIN, AM; I STEFFAN-DEWENTER & T TSCHARNTKE. 2003. Fruit set of highland coffee increases with the diversity of pollinating bees. Proceedings of the Royal Society 270:955-961.

KLINKHAMER, P & TJ JONG. 1990. Effects of plant density and sex differential reward on pollination visitation in the protandrous Echium vulgare (Boraginaceae). Oikos 57:399-405.

KWAK, M. 1987. Pollination and pollen flow disturbed by honeybees in bumblebee-pollinated Rhinanthus population? Pages 273-283 en J Van Andel, editor. Disturbance in grasslands. Dr. W. Junk, Dordrecht, Netherlands.

LEGENDRE, P & L LEGENDRE. 1998. Numerical Ecology. Elsevier.

LEÓN, RJC; D BRAN; M COLLANTES; JM PARUELO & A SORIANO. 1998. Grandes unidades de vegetación de la Patagonia extra andina. Ecologia Austral 8:125-144.

LOVEJOY, T; ROJ BIERREGAARD; AB RYLANDS; CE QUINTELA; LH HARPER; KSJ BROWN; AH POWELL & GVN POWELL. 1986. Edge and other effects of isolation on Amazon forest fragments. Pag. 257-285 en ME Soulé, editor. Conservation biology: the science of scarcity and diversity. Sinauer, Sunderland, Massachusetts, USA.

MASCHINSKI, J & TG WHITHAM. 1989. The continuum of plant responses to herbivory: The influence of plant association, nutrient availability, and timing. American Naturalist 134:1-19.

MCNAUGHTON, SJ. 1983. Compensatory plant growth as a response to herbivory. Oikos 40:329-336.

MEMMOTT, J; NM WASER & MV PRICE. 2004. Tolerance of pollination networks to species extinctions. Proceedings of the Royal Society of London, Series B 271:2605-2611.

MILCHUNAS, D; O SALA & WK LAUENROTH. 1988. A generalized model of the effects of grazing by large herbivores on grassland community structure. American Naturalist 132:87-106.

MILLER, R; T SVEJCAR & N WEST. 1994. Implications of livestock herbivory in the intermountain sagebrush region: plant composition. Pag. 101-146 en M Vavra, WA Laycock, y R Pieper, editores. Ecological implications of livestock herbivory in the west. Society for Range Managment, Denver.

MIYASHITA, T; M TAKADA & A SHIMAZAKI. 2004. Indirect effects of herbivory by deer reduce abundance and species richness of web spiders. Écoscience 11:74-79.

MORRIS, WF. 2003. Which mutualists are most essential? Buffering of plant reproduction against the extinction of pollinators. Princeton University Press, Princeton.

MURCIA, C. 1995. Edge effects in fragmented forests: Implications for conservation. Trends in Ecology and Evolution 10:58-62.

MURCIA, C. 1996. Forest fragmentation and the pollination of neotropical plants. Pages 19-36 Forest Patches in tropical landscapes. Island Press, Washington, D.C., Covelo, California.

PAIGE, KN. 1992. Overcompensation in response to mammalian herbivory: from mutualistic to antagonistic interactions. Ecology 73:2076-2085.

PARUELO, JM; A BELTRÁN; E JOBBÁGY; OE SALA & RA GOLLUSCIO. 1998. The climate of Patagonia: general patterns and controls on biotic processes. Ecologia
Austral 8:85-101.

SAUNDERS, D; R HOBBS & C MARGULES. 1991. Biological consequences of ecosystem fragmentation: a review. Conservation Biology 5:18-32.

SHIPLEY, B. 2000. Cause and Correlation in Biology: a user guide to path analysis, structural equations and causal inference. Cambridge University Press, Cambridge.

SIH, A & MS BALTUS. 1987. Patch size, pollinator behavior, and pollinator limitation in catnip. Ecology 68:1679-1690.

SOWIG, P. 1989. Effects of flowering plant ́s patch size on species composition of pollinator communities, foraging strategies, and resource partitioning in bumblebees (Hymenoptera: Apidae). Oecologia 78:550-558.

STRAUSS, SY & WS ARMBRUSTER. 1997. Linking herbivory and pollination: new perspectives on plant and animal ecology and evolution. Ecology 78:1617-1618.

STRAUSS, SY; JK CONNER & SL RUSH. 1996. Foliar herbivory affects floral characters and plant attractiveness to pollinators: implications for male and female plant fitness. American Naturalist 147:1098-1107.

TADEY, M. 2006. Grazing without grasses: Effects of introduced livestock on plant community composition in an arid environment in northern Patagonia. Applied Vegetation Science 9:109-116.

TADEY, M. 2007. Efectos del pastoreo sobre la polinización y reproducción de plantas del Monte Patagónico. Tesis de Doctorado. Universidad Nacional del Comahue, S. C. de Bariloche.

TADEY, M & AG FARJI-BRENER. 2007a. Indirect effects of exotic grazers: livestock decreases the nutrient content of refuse dumps of leaf-cutting ants through vegetation impoverishment. Journal of Applied Ecology 44:1209-1218.

TADEY, M & AG FARJI-BRENER. 2007b. Identifying direct and indirect effects of exotic grazers on native plant cover in the Monte desert of Argentina. Journal of Arid Environment 69:526–536.

VALLENTINE, JF. 2001. Grazing management. Academic Press, San Diego, CA, US.

VAUGHTON, G. 1992. Effectiveness of nectarivorous birds and honeybees as pollinators of Branksia spinulosa (Proteacea). Australian Journal of Ecology 17:43-50.

VÁZQUEZ, DP & D SIMBERLOF. 2003. Changes in interaction biodiversity induced by an introduced ungulate. Ecology Letters 6:1077-1083.

VÁZQUEZ, DP & D SIMBERLOFF. 2004. Indirect effects of an introduced ungulate on pollination and plant reproduction. Ecological Monographs 74:281-308.

VÁZQUEZ, DP & MA AIZEN. 2004. Asymmetric specialization: a pervasive feature of plant-pollinator interactions. Ecology 85:1251-1257.

WASER, NM. 1989. Optimal outcrossing in Ipomopsis aggregata: Seed set and offspring fitness. Evolution 43:1097-1109.

WATKINSON, AR & SJ ORMEROD. 2001. Grasslands, grazing and biodiversity: editors’ introduction. Journal of Applied Ecology 38:233-237.

Published

2008-04-01

How to Cite

Tadey, M. (2008). Livestock effect on pollination levels in native plant species of the Patagonian Monte desert. Ecología Austral, 18(1), 089–100. Retrieved from https://ojs.ecologiaaustral.com.ar/index.php/Ecologia_Austral/article/view/1399

Issue

Section

Articles