TY - JOUR
T1 - Clumped planting arrangements improve seed production in a revegetated eucalypt woodland
AU - McCallum, Kimberly P.
AU - Breed, Martin F.
AU - Paton, David C.
AU - Lowe, Andrew J.
PY - 2019/5
Y1 - 2019/5
N2 - The arrangement of plants within revegetated sites is rarely considered an important characteristic of these communities. However, in natural systems, plant spatial arrangements can influence a range of ecological processes, including pollination and seed set. Pollinators tend to preferentially visit larger and/or more closely spaced populations, with plants in these populations generally receiving more outcrossed pollen, resulting in increased seed set and better quality seed. Similar trends may occur in revegetated populations, but little is known about the influence of planting arrangement on seed production in restored systems. Here, we quantified the effect of plant abundance (number of conspecifics within 100 m) and distance to nearest reproductive conspecific on the level of seed set for six eucalypt species (n = 422 trees in total) in 1 year and for one of these species (Eucalyptus leucoxylon), across three additional years. Seed number per fruit was highly variable both between individuals and within individuals across years. Despite this variability, there was a consistent trend of higher seed production (seed number per fruit) when another reproductive conspecific was within 20 m. In contrast, plant abundance had little influence on seed production. Further investigation of nearest neighbor arrangements found the distance to either the first, second, third, or fourth reproductive neighbors were the key predictors of seed production. Therefore, revegetation designs that consider plant spacing and aggregation, rather than only planting to overall density criteria (i.e. trees/ha), at least for the eucalypts studied here, has the potential to improve seed production in revegetated populations.
AB - The arrangement of plants within revegetated sites is rarely considered an important characteristic of these communities. However, in natural systems, plant spatial arrangements can influence a range of ecological processes, including pollination and seed set. Pollinators tend to preferentially visit larger and/or more closely spaced populations, with plants in these populations generally receiving more outcrossed pollen, resulting in increased seed set and better quality seed. Similar trends may occur in revegetated populations, but little is known about the influence of planting arrangement on seed production in restored systems. Here, we quantified the effect of plant abundance (number of conspecifics within 100 m) and distance to nearest reproductive conspecific on the level of seed set for six eucalypt species (n = 422 trees in total) in 1 year and for one of these species (Eucalyptus leucoxylon), across three additional years. Seed number per fruit was highly variable both between individuals and within individuals across years. Despite this variability, there was a consistent trend of higher seed production (seed number per fruit) when another reproductive conspecific was within 20 m. In contrast, plant abundance had little influence on seed production. Further investigation of nearest neighbor arrangements found the distance to either the first, second, third, or fourth reproductive neighbors were the key predictors of seed production. Therefore, revegetation designs that consider plant spacing and aggregation, rather than only planting to overall density criteria (i.e. trees/ha), at least for the eucalypts studied here, has the potential to improve seed production in revegetated populations.
KW - ecosystem function
KW - nearest neighbor distance
KW - plant spatial pattern
KW - pollination
KW - reproduction
KW - restoration planting
UR - http://www.scopus.com/inward/record.url?scp=85058243171&partnerID=8YFLogxK
UR - http://purl.org/au-research/grants/arc/DE150100542
UR - http://purl.org/au-research/grants/arc/DP150103414
U2 - 10.1111/rec.12905
DO - 10.1111/rec.12905
M3 - Article
AN - SCOPUS:85058243171
VL - 27
SP - 638
EP - 646
JO - Restoration Ecology
JF - Restoration Ecology
SN - 1061-2971
IS - 3
ER -