Alexandra-Maria Klein

Alexandra-Maria Klein


Research Focus & Metrics

Academic Career Length

25Years (2002-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
27 October 2006 in Proceedings Of The Royal Society B-Biological Sciences
Verified
Journal Article
Closed access
AKAlexandra-Maria Klein
Alexandra-Maria Klein
BVBernard E Vaissière
Bernard E Vaissière
JCJames H Cane
James H Cane
ISIngolf Steffan-Dewenter
Ingolf Steffan-Dewenter
SCSaul A Cunningham
Saul A Cunningham
TTTeja Tscharntke
Teja Tscharntke
The extent of our reliance on animal pollination for world crop production for human food has not previously been evaluated and the previous estimates for countries or continents have seldom used primary data. In this review, we expand the previous estimates using novel primary data from 200 countries and found that fruit, vegetable or seed production from 87 of the leading global food crops is dependent upon animal pollination, while 28 crops do not rely upon animal pollination. However, global production volumes give a contrasting perspective, since 60% of global production comes from crops that do not depend on animal pollination, 35% from crops that depend on pollinators, and 5% are unevaluated. Using all crops traded on the world market and setting aside crops that are solely passively self-pollinated, wind-pollinated or parthenocarpic, we then evaluated the level of dependence on animal-mediated pollination for crops that are directly consumed by humans. We found that pollinators are essential for 13 crops, production is highly pollinator dependent for 30, moderately for 27, slightly for 21, unimportant for 7, and is of unknown significance for the remaining 9. We further evaluated whether local and landscape-wide management for natural pollination services could help to sustain crop diversity and production. Case studies for nine crops on four continents revealed that agricultural intensification jeopardizes wild bee communities and their stabilizing effect on pollination services at the landscape scale.

23 June 2005 in Ecology Letters
Verified
Journal Article
Closed access
TTTeja Tscharntke
Teja Tscharntke
AKAlexandra-Maria Klein
Alexandra-Maria Klein
AKAndreas Kruess
Andreas Kruess
ISIngolf Steffan‐Dewenter
Ingolf Steffan‐Dewenter
CTCarsten Thies
Carsten Thies

29 March 2013 in Science
Verified
Journal Article
Open access
PDF file
LGLucas Alejandro Garibaldi
Lucas Alejandro Garibaldi
ISIngolf Steffan-Dewenter
Ingolf Steffan-Dewenter
RWRachael Winfree
Rachael Winfree
MAMarcelo A. Aizen
Marcelo A. Aizen
RBRiccardo Bommarco
Riccardo Bommarco
AKAlexandra-Maria Klein
Alexandra-Maria Klein
Honeybees Can't Do It Alone: The majority of food crops require pollination to set fruit with the honeybee providing a pollination workhorse, with both feral and managed populations an integral component of crop management (see the Perspective by Tylianakis , published online 28 February). Garibaldi et al. (p. 1608 , published online 28 February) now show that wild pollinators are also a vital part of our crop systems. In more than 40 important crops grown worldwide, wild pollinators improved pollination efficiency, increasing fruit set by twice that facilitated by honeybees. Burkle et al. (p. 1611 , published online 28 February) took advantage of one of the most thorough and oldest data sets available on plant-pollinator interaction networks and recollected data on plant-pollinator interactions after more than 120 years of climate change and landscape alteration. The historical data set consists of observations collected by Charles Robertson near Carlinville, Illinois (USA), in the late 1800s on the phenology of plants and their pollinating insects, as well as information about which plants and pollinators interacted with one another. Many sites were revisited in the early 1970s and in 2009 and 2010 to collect similar plant-pollinator data. Pollinator function has declined through time, with bees showing lower visitation rates and lower fidelity to individual plant species.

24 January 2012 in Biological Reviews
Verified
Journal Article
Closed access
PDF file
TTTeja Tscharntke
Teja Tscharntke
JTJason Tylianakis
Jason Tylianakis
TRTatyana A. Rand
Tatyana A. Rand
RDRaphael K. Didham
Raphael K. Didham
LFLenore Fahrig
Lenore Fahrig
CWCatrin Westphal
Catrin Westphal

16 February 2007 in Ecology Letters
Verified
Journal Article
Open access
PDF file
CKClaire Kremen
Claire Kremen
NWNeal M. Williams
Neal M. Williams
MAMarcelo A. Aizen
Marcelo A. Aizen
BGBarbara Gemmill‐Herren
Barbara Gemmill‐Herren
GLGretchen LeBuhn
Gretchen LeBuhn
TRTaylor H. Ricketts
Taylor H. Ricketts
Many ecosystem services are delivered by organisms that depend on habitats that are segregated spatially or temporally from the location where services are provided. Management of mobile organisms contributing to ecosystem services requires consideration not only of the local scale where services are delivered, but also the distribution of resources at the landscape scale, and the foraging ranges and dispersal movements of the mobile agents. We develop a conceptual model for exploring how one suchmobile‐agent‐based ecosystem service(MABES), pollination, is affected by land‐use change, and then generalize the model to other MABES. The model includes interactions and feedbacks among policies affecting land use, market forces and the biology of the organisms involved. Animal‐mediated pollination contributes to the production of goods of value to humans such as crops; it also bolsters reproduction of wild plants on which other services or service‐providing organisms depend. About one‐third of crop production depends on animal pollinators, while 60–90% of plant species require an animal pollinator. The sensitivity of mobile organisms to ecological factors that operate across spatial scales makes the services provided by a given community of mobile agents highly contextual. Services vary, depending on the spatial and temporal distribution of resources surrounding the site, and on biotic interactions occurring locally, such as competition among pollinators for resources, and among plants for pollinators. The value of the resulting goods or services may feed back via market‐based forces to influence land‐use policies, which in turn influence land management practices that alter local habitat conditions and landscape structure. Developing conceptual models for MABES aids in identifying knowledge gaps, determining research priorities, and targeting interventions that can be applied in an adaptive management context.

19 February 2008 in Ecology Letters
Verified
Journal Article
Open access
PDF file
TRTaylor H. Ricketts
Taylor H. Ricketts
JRJames Regetz
James Regetz
ISIngolf Steffan‐Dewenter
Ingolf Steffan‐Dewenter
SCSaul A. Cunningham
Saul A. Cunningham
CKClaire Kremen
Claire Kremen
BVBlande F. Viana
Blande F. Viana
Pollination by bees and other animals increases the size, quality, or stability of harvests for 70% of leading global crops. Because native species pollinate many of these crops effectively, conserving habitats for wild pollinators within agricultural landscapes can help maintain pollination services. Using hierarchical Bayesian techniques, we synthesize the results of 23 studies – representing 16 crops on five continents – to estimate the general relationship between pollination services and distance from natural or semi‐natural habitats. We find strong exponential declines in both pollinator richness and native visitation rate. Visitation rate declines more steeply, dropping to half of its maximum at 0.6 km from natural habitat, compared to 1.5 km for richness. Evidence of general decline in fruit and seed set – variables that directly affect yields – is less clear. Visitation rate drops more steeply in tropical compared with temperate regions, and slightly more steeply for social compared with solitary bees. Tropical crops pollinated primarily by social bees may therefore be most susceptible to pollination failure from habitat loss. Quantifying these general relationships can help predict consequences of land use change on pollinator communities and crop productivity, and can inform landscape conservation efforts that balance the needs of native species and people.