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Using Big Science to Manage Vernal Pool Grasslands
Jaymee MartyThe Nature Conservancy
Cosumnes River
We own it, now what?
• Change Current Management – Seasonal Grazing (Oct – June): change to no
grazing in wet season• Rotational grazing MUST be better• Political reasons
– Add fire to control weeds• Science based?
– No replicated studies on either subject– Keep guessing or set up robust monitoring
Valley SpringsFormation
LagunaFormation
Grazing Treatment Layout
Ungrazed
Dry season grazed
Continuously grazed
Wet season grazed
Native species richness in ungrazedpools: doing fine?
0
2
4
6
8
10
12
Pool Edge Upland
Nat
ive
s 2001
2002
2003
Change in native richness positive in grazed poolsnegative in ungrazed pools
(Marty 2005)
-2.50
-2.00
-1.50
-1.00
-0.50
0.00
0.50
1.00
1.50
2.00
2.50
pool edge upland
Cha
nge
in s
(03
- 01)
CG
DG
UG
WG
n.s. ***
n.s., not significant; * p < 0.05; ** p < 0.01; *** p < 0.001
7665
78
115
0
20
40
60
80
100
120
140
cg dg ug wg
Max
imum
pon
ding
per
iod
(# d
ays)
Average maximum ponding period 50 days less in ungrazed poolsvs. continuously grazed pools
a
b bb
HYPOTHESIS: Fire occurred historically in the system,
so it must be good
Valensin Ranch (Riverbank)
Jepson Prairie Preserve(Northern Claypan)
Vina Plains Preserve (Tuscan)
Howard Ranch (Valley Springs)
5 pools
5 pools
5 pools
5 pools
One year post burn results
0
10
20
30
40
50
60
edge pool upland
% c
over
exo
tic a
nnua
l gra
sses
burnedunburned
n.s
*
**
Exotic annual GRASS cover declines in burned plots at 2003 burned sites
Exotic annual FORB cover increases in burned plots at 2003 burned s
05
101520253035404550
edge pool upland
% c
over
exo
tic a
nnua
l for
bs
burnedunburned
n.s
n.s
***
0
20
40
60
80
100
120
edge pool upland
% c
over
nat
ives
burnedunburned
Burning increases native cover and richness at Jepson Prairie(and Valensin Ranch)
0
2
4
6
8
10
12
edge pool upland
Nat
ive
spec
ies
rich
ness
burnedunburned
+
**
***
n.s.
**
***
No effect of burning on native diversity at Vina and Cosumnes Foothills sites
0
2
4
6
8
10
12
14
16
edge pool upland
Nat
ive
s
0
2
4
6
8
10
12
edge pool uplandN
ativ
e s
burned
unburned
n.s.
n.s. n.s.
n.s. n.s.
n.s.
• Don’t change management regime unless you have a very
compelling science-based reason to do so
• Sometimes politics get in the way
• When you do make a change, MONITOR
• ALWAYS include a control
• Know why you’re monitoring and keep it simple
• Stats heads may know numbers, but may not
understand biology or monitoring efficiency
• Analyze your data!
What have we learned?
HelpersCRP Interns and staffVolunteer naturalistsCRP Hard Corp crewSac Co. Sheriff work crewsCDF
Generous funding support:Osher foundationAnderson Grassland Research fundThe McCammantsPartnership FoundationThe Bechtel Foundation
