NSF Org:	DEB Division Of Environmental Biology
Recipient:	COLORADO STATE UNIVERSITY
Initial Amendment Date:	January 17, 2017
Latest Amendment Date:	January 17, 2017
Award Number:	1712786
Award Instrument:	Standard Grant
Program Manager:	Matthew Kane mkane@nsf.gov  (703)292-7186 DEB  Division Of Environmental Biology BIO  Directorate for Biological Sciences
Start Date:	February 1, 2017
End Date:	January 31, 2019 (Estimated)
Total Intended Award Amount:	$70,439.00
Total Awarded Amount to Date:	$70,439.00
Funds Obligated to Date:	FY 2017 = $70,439.00
History of Investigator:	Melinda Smith (Principal Investigator) melinda.smith@colostate.edu Scott Collins (Co-Principal Investigator) Alan Knapp (Co-Principal Investigator) Deron Burkepile (Co-Principal Investigator) Sally Koerner (Co-Principal Investigator)
Recipient Sponsored Research Office:	Colorado State University 601 S HOWES ST FORT COLLINS CO  US  80521-2807 (970)491-6355
Sponsor Congressional District:	02
Primary Place of Performance:	Kruger National Park Skukuza  SF
Primary Place of Performance Congressional District:
Unique Entity Identifier (UEI):	LT9CXX8L19G1
Parent UEI:
NSF Program(s):	ECOSYSTEM STUDIES
Primary Program Source:	01001718DB NSF RESEARCH & RELATED ACTIVIT
Program Reference Code(s):	7914
Program Element Code(s):	118100
Award Agency Code:	4900
Fund Agency Code:	4900
Assistance Listing Number(s):	47.074

ABSTRACT

Kruger National Park (KNP), a biodiversity hotspot, is experiencing one of its worst droughts on record. This drought has resulted in large declines in forage for many grazing species, which have experienced significant population declines as a result. The remaining animals have been left to consume low quality, mostly unpalatable, forage. How these changes may alter future plant communities is not known. For almost a decade, scientists have been studying the impact of fire frequency and large grazers on ecosystem processes in savanna grassland in KNP under what used to be considered normal climatic conditions. With the onset of extreme drought, they now have an opportunity to study how the effects of fire and grazing may change as climatic conditions change, and what this might mean for plant productivity and populations of large grazer species. Climate models predict an intensification of climate extremes globally, a phenomenon that is already evident in weather patterns today, so there is a great need to develop a better understanding of how these rare climatic events may be reshaping ecosystems. In addition to enhancing understanding of savanna grasslands and testing fundamental ecological theory, this research will provide crucial information on the impact of climate extremes on plants and their grazers, which will be of great value to decision makers that manage national parks.

The proposed research will document the effects of a historically exceptional drought on a savanna grassland (characterized by a mixture of both woody and herbaceous plants) in KNP in the context of an existing long-term grazing and fire experiment. Documenting the potentially transformational nature of rare climatic events is in itself an opportunity seldom afforded ecologists, but to have pre-treatment data and a long-term, well-replicated experiment in place that manipulates the key disturbances most likely to interact with extreme drought is unprecedented. Because forecasts are for this exceptional drought to conclude in early 2017, this RAPID project focuses on gathering data at the end of this exceptional climate event to assess the potential for drought, fire and grazing to trigger a shift in the plant community that will result in an increase in the relative abundance of palatable grasses. This research has implications for not only understanding the determinants of grassland biodiversity, but also for increasing our knowledge of how rare climate extremes may transform ecosystems. Currently, KNP managers are grappling with a long-term trend of grassland degradation which has led to the loss of palatable forage for wildlife. The current exceptional drought, while exacerbating this problem in the short-term, may increase forage quality across much of KNPs grasslands. In addition, this project will establish close collaborative ties between US researchers and scientists in South Africa. The lead scientists on this project will continue to work closely with KNP scientists to ensure that all results are communicated in a way to inform management decisions in KNP. Dissemination of all datasets and results will be achieved via a dedicated webpage, housed at Colorado State University.

PROJECT OUTCOMES REPORT

Disclaimer

This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.

In 2015 and 2016, much of South Africa (SA) experienced “extreme” to “exceptional” drought. At the epicenter of this region lies Kruger National Park (KNP), the crown jewel of the SA National Parks system. KNP is a 20,000 km² protected area that harbors one of the most diverse assemblages of large herbivores and carnivores in SA. Long-term climate records indicated that KNP experienced one of its worst droughts on record during this time period. Climatic extremes, such as this exceptional drought, are by definition rare - yet they may have transformational and long-lasting impacts on ecosystems.

Drought strongly impacts savanna ecosystem structure and function, leading to decreased productivity, reduced abundances of palatable grasses, and widespread herbivore mortality. We have limited understanding of how severe drought interact with natural disturbances, such as fire and grazing, both of which are essential for the maintenance of grasslands and savannas globally. Given that more frequent climate extremes are forecasted and have already been observed (IPCC 2012), there is a pressing scientific need to better understand the impacts of these extreme events on terrestrial ecosystems, particularly in biodiversity hotspots such as KNP.

Since 2006, we have been assessing responses of savanna grassland in KNP to experimental alterations in both fire and grazing. As a result, we have a decade of pre-drought data and a solid understanding of how fire regimes and grazing pressures interact under typical climatic conditions. Funding from this RAPID award allowed us to assess the potentially transformational effects of an exceptional drought by continuing to sample our existing long-term fire-grazing experiment. We predicted that unpalatable grasses would decline, and palatable forage grasses would increase rapidly when the drought ended. We predicted that these responses would be strongest under high fire return frequencies (every 1 to 3 years). Data collected with RAPID funding supported our predictions. Thus, although tragic from a wildlife perspective, severe drought is a triggering mechanism that can increase landscape scale palatability under relatively high historical fire frequencies. Our research provides vital information to park managers and allowed us to develop a new understanding of the potential resilience of these savanna ecosystems to extreme drought.  

Last Modified: 05/16/2019
Modified by: Scott L Collins

Please report errors in award information by writing to: awardsearch@nsf.gov.