Burying, not broadcasting seeds improves the seedling establishment of most woody species under different ecological conditions in a semiarid ecosystem of central Chile

2021 ◽  
Author(s):  
Pablo I. Becerra ◽  
Naijem Aqueveque ◽  
Nicolás Velasco
Author(s):  
M. Celeste Díaz Vélez ◽  
Ana E. Ferreras ◽  
Valeria Paiaro

Abstract Animal dispersers are essential for many non-native plants since they facilitate seed movement and might promote seed germination and seedling establishment, thereby increasing their chances of invasion. This chapter reviews the published literature on seed dispersal of non-native plant species by native and/or non-native animals. The following questions are addressed: (i) Are interactions between non-native plants and their animal dispersers evenly studied worldwide? (ii) Which are the distinctive traits (i.e. geographical origin, life form, dispersal strategy and propagule traits) of non-native plants that are dispersed by animals? (iii) Which are the most studied groups of dispersers of non-native plants around the world? (iv) Does the literature provide evidence for the Invasional Meltdown Hypothesis (non-native plant-non-native disperser facilitation)? (v) What is the role of animal dispersers at different stages of the non-native plant regeneration process? Our dataset of 204 articles indicates that geographical distribution of the studies was highly heterogeneous among continents, with the highest number coming from North America and the lowest from Asia and Central America. Most of the non-native plants involved in dispersal studies were woody species from Asia with fleshy fruits dispersed by endozoochory. More than the half of the animal dispersal agents noted were birds, followed by mammals, ants and reptiles. The dominance of bird-dispersal interactions over other animal groups was consistent across geographical regions. Although most of the studies involved only native dispersers, interactions among non-native species were detected, providing support for the existence of invasional meltdown processes. Of the total number of reviewed articles reporting seed removal, 74% evaluated seed dispersal, but only a few studies included seed germination (35.3%), seedling establishment (5.4%) or seed predation (23.5%). Finally, we discuss some research biases and directions for future studies in the area.


Author(s):  
M. Celeste Díaz Vélez ◽  
◽  
Ana E. Ferreras ◽  
Valeria Paiaro ◽  
◽  
...  

Animal dispersers are essential for many non-native plants since they facilitate seed movement and might promote seed germination and seedling establishment, thereby increasing their chances of invasion. This chapter reviews the published literature on seed dispersal of non-native plant species by native and/or non-native animals. The following questions are addressed: (i) Are interactions between non-native plants and their animal dispersers evenly studied worldwide? (ii) Which are the distinctive traits (i.e. geographical origin, life form, dispersal strategy and propagule traits) of non-native plants that are dispersed by animals? (iii) Which are the most studied groups of dispersers of non-native plants around the world? (iv) Does the literature provide evidence for the Invasional Meltdown Hypothesis (non-native plant-non-native disperser facilitation)? (v) What is the role of animal dispersers at different stages of the non-native plant regeneration process? Our dataset of 204 articles indicates that geographical distribution of the studies was highly heterogeneous among continents, with the highest number coming from North America and the lowest from Asia and Central America. Most of the non-native plants involved in dispersal studies were woody species from Asia with fleshy fruits dispersed by endozoochory. More than the half of the animal dispersal agents noted were birds, followed by mammals, ants and reptiles. The dominance of bird-dispersal interactions over other animal groups was consistent across geographical regions. Although most of the studies involved only native dispersers, interactions among non-native species were detected, providing support for the existence of invasional meltdown processes. Of the total number of reviewed articles reporting seed removal, 74% evaluated seed dispersal, but only a few studies included seed germination (35.3%), seedling establishment (5.4%) or seed predation (23.5%). Finally, we discuss some research biases and directions for future studies in the area.


2013 ◽  
Vol 291 ◽  
pp. 300-307 ◽  
Author(s):  
Paula Inés Marcora ◽  
Daniel Renison ◽  
Ana Inés País-Bosch ◽  
Marcelo Ruben Cabido ◽  
Paula Andrea Tecco

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248619
Author(s):  
Natalio Roque Marca ◽  
Ramiro Pablo López ◽  
Kazuya Naoki

Germination and seedling establishment are two critical processes in the life cycle of plants. Seeds and seedlings must pass through a series of abiotic and biotic filters in order to recruit as members of their communities. These processes are part of the regeneration niche of the species. In arid regions, the regeneration niche is frequently associated to facilitation by shade. Facilitation is a positive interaction between plants, in which one of them acts as a benefactor (the nurse) of the other (the beneficiary). The result of this interaction can be reflected in the increased growth, survival, and/or reproduction of the beneficiary plant. In this study, we determined experimentally the effect of shade and irrigation on the germination and early survival of dominant species of a semi-arid Andean region, the Bolivian Prepuna. An experiment with Acacia feddeana, Prosopis ferox, Cercidium andicola (woody species), Parodia maassii, and Oreocereus celsianus (cactus species) was carried out at an experimental garden in La Paz, Bolivia, with a bifactorial design, considering shaded and unshaded pots, subjected to two irrigation treatments (≈50 and 80 mm of rainfall during the whole study period). Microenvironmental conditions did not affect the seed germination of the woody species. However, they showed differences in seedling survival: A. feddeana survived better under shade, whereas P. ferox and C. andicola survived better without shade. Cercidium andicola, compared to P. ferox, was more affected by shade and low irrigation. Although germination success of cacti was low, both species germinated better under shade and with high irrigation. These results showed differences in the regeneration niche of dominant species of the Prepuna which may favor their coexistence and which may be characteristic of other dry Andean regions.


1991 ◽  
Vol 39 (4) ◽  
pp. 347 ◽  
Author(s):  
RA Bradstock

Observations and experiments were performed to examine the relationship between fire and seedling establishment in the following serotinous/woody species: Banksia ericifolia L.f., Banksia serrata L.f., Petrophile pulchella (Schrad.) R. Br. and Isopogon anemonifolius (Salisb.) Knight. For all species a moderate-intensity fire had no effect on the viability of seeds stored in cones compared to seeds stored in unburnt cones. Germinated seeds of all species, placed in meshed and unmeshed enclosures within an unburnt area, were consumed extensively by an unknown predator within 2 months of placement. No such effect occurred in similar treatments within a recently burnt area. Heating of the soil surface and the nature of substrates (litter, ash, bare soil) had variable effects on seedling establishment. Establishment of B. ericifolia and B. serrata was unaffected by the treatments whereas in P. pulchella and I. anemonifolius substrates and heating had significant effects. In P. pulchella establishment was significantly reduced on litter compared with pure ash. In I. Anemonifolius establishment was significantly higher on treatments with litter or mixed ash, except on soils that had received the low heat treatment, where there was no significant substrate effect. It was concluded that fire could create a more favourable soil-surface environment for establishment in P. pulchella only. In the other species, fire would have no effect or, in I. Anemonifolius, establishment might be enhanced in unburnt conditions. This conclusion does not take into account the effects of cover (overstorey and understorey) on establishment. It was concluded that predation of newly germinated seedlings may be the most important restriction on seedling establishment in unburnt populations.


2016 ◽  
Vol 32 (4) ◽  
pp. 300-313 ◽  
Author(s):  
Waldemar Zangaro ◽  
Luis Eduardo Azevedo Marques Lescano ◽  
Enio Massao Matsuura ◽  
Artur Berbel Lirio Rondina ◽  
Marco Antonio Nogueira

Abstract:The competitive influence of the root system of the exotic grass Urochloa brizantha and the widespread forb Leonotis nepetifolia on the emergence, survival and early growth of the seedlings of eight tropical heliophilous herbaceous species, six early-successional woody species and five late-successional woody species from Brazil, grown in 3500-cm3 pots and in greenhouse without light restriction were assessed. The density of fine-root systems produced by the forb and the grass in pots were 6.8 cm cm−3 soil and 48.1 cm cm−3 soil, respectively. Seedlings survival of the heliophilous herbaceous, early- and late-successional woody species were 86%, 70% and 100% in presence of the forb root system and 12%, 14% and 100% in competition with grass root system, respectively. The competitive pressure applied by the grass root system on seedling growth of the heliophilous herbaceous, early- and late-successional woody species were 2.4, 1.9 and 1.4 times greater than the forb root system. Total root length of the heliophilous herbaceous, early- and late-successional woody species grown without competitors were 13, 33 and 5 times greater than in competition with forb, and were 66, 54 and 6 times greater than in competition with grass root system, respectively. The averages of fine-root diameter of plants grown without competitors were 209 μm for the heliophilous herbaceous, 281 μm for early-successional trees and 382 μm for late-successional trees. The root system of the forb did not avoid seedling establishment of most plant species, but the grass root system hampered more the establishment of heliophilous herbaceous and early-successional woody species than the seedling establishment of late-successional woody species. The different density of root systems produced in soil by the forb and the grass, and the distinct root traits (e.g. root diameter and root tissue density) of the early- and late-successional plant species can explain the differences in the establishment of seedlings of plant species belonging to different groups of tropical succession when exposed to below-ground competition.


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