Tabla 2

Table 2. Types of tests commonly used for measuring leaf mechanical properties

Parameter Tearing test Shearing test Punch test
Property measured Leaf resistance to a tearing force, Ft Leaf resistance to a shearing force, Ws Leaf resistance to a punching force, Fp
Unit Nmm–1 Jm–1 Nmm–1
Apparatus Tearing apparatus (Hendry and Grime
1993); universal testing machine:
4202, Instron, High Wycombe,
Bucks, UK (Wright and Illius 1995)
Leaf-cutter machine (Wright and
Cannon 2001); scissoring machine
(Darvell et al. 1996); universal
testing machine: 4202, Instron,
High Wycombe, Bucks, UK
(Wright and Illius 1995)
Universal testing machine: 5542,
Instron, Canton, MA, USA (Onoda
et al. 2008); Shimadzu DCS-5000
(Lucas et al. 1991)
Study objective Herbivory by mammalian grazers and
other tearing herbivores (e.g.
snails); decomposition;
identification of plant resource-use
strategies
Herbivory by chewing insects and
small vertebrates; herbivore impacts
on vegetation (e.g. trampling);
decomposition; identification of
plant resource-use strategies
Herbivory by chewing or sucking
insects; decomposition;
identification of plant resource-use
strategies