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Nurse plant theory and its application in ecological restoration in lower subtropics of China

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Nurse plants are those that facilitate the growth and development of other plant species (target species) beneath their canopy because they offer benign microhabitats that are more favorable for seed germination and/or seedling recruitment than their surrounding envi-ronment. Nurse plants have been mainly used to restore vegetation in arid and sub-arid zones in recent years. Based on summarizing the definition of nurse plant and target plant, we review the nursing effect mechanisms, ecological factors that influence nursing effect, rela-tionships between nurse plant and ecological restoration. This review also brings forward possible pairs of nurse and target species at lower subtropical areas. Furthermore, we provide the potential tendency in nurse plant research and application.
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Review
Nurse plant theory and its application in ecological restoration
in lower subtropics of China
Hai Ren
*
, Long Yang, Nan Liu
Heshan National Field Research Station of Forest Ecosystem, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou 510650, China
Received 28 May 2007; received in revised form 13 July 2007; accepted 13 July 2007
Abstract
Nurse plants are those that facilitate the growth and development of other plant species (target species) beneath their canopy because
they offer benign microhabitats that are more favorable for seed germination and/or seedling recruitment than their surrounding envi-
ronment. Nurse plants have been mainly used to restore vegetation in arid and sub-arid zones in recent years. Based on summarizing the
definition of nurse plant and target plant, we review the nursing effect mechanisms, ecological factors that influence nursing effect, rela-
tionships between nurse plant and ecological restoration. This review also brings forward possible pairs of nurse and target species at
lower subtropical areas. Furthermore, we provide the potential tendency in nurse plant research and application.
Ó2007 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited and Science in
China Press. All rights reserved.
Keywords: Nurse plant; Target species; Forest restoration; Nursing effect
1. Introduction
The relationship between plants, mainly including com-
petition (negative effect), neutral, and facilitation (positive
effect), is an important driving force of plant community
succession or vegetation restoration. Ecological research
has been focused on competition. Research on positive
interaction between plants is still ignored [1] although it
is gradually known as competition and facilitation (at
least one side benefit) in the plant communities of the
main biome of the world in the past 15 years. Nurse
plants are those which facilitate the growth and develop-
ment of other plant species (target species) beneath their
canopy because they offer benign microhabitats that are
more favorable for seed germination and/or seedling
recruitment than their surrounding environment, for
adjusting light, temperature, soil humidity and nutrient,
as well as avoiding grazing [2,3]. Nurse plants can also
establish the seedlings of target species through positive
interaction between plants. Nursing effect is mainly
accomplished by the interactions between plants, which
influence community structure and dynamic performance
intensively and the appearance or absence of specific spe-
cies [2,3]. So the research on nurse plant can validate,
consummate and enrich the theory that interactions
among plant species drive the natural succession, which
also provides the meaning of ecological restoration. In
this paper we review the application of nurse plant in res-
toration ecology and the future development of this
research field and especially discuss the possible pairs of
nurse and target species at lower subtropical areas and
its applications in forest restoration.
2. Nurse plant and target species
2.1. Nurse plant
Nurse plant plays an important role in recovering the
structures and functions of primary ecosystem and is
1002-0071/$ - see front matter Ó2007 National Natural Science Foundation of China and Chinese Academy of Sciences. Published by Elsevier Limited
and Science in China Press. All rights reserved.
doi:10.1016/j.pnsc.2007.07.008
*
Corresponding author. Tel.: +86 20 37252916; fax: +86 20 37252831.
E-mail address: renhai@scib.ac.cn (H. Ren).
Available online at www.sciencedirect.com
Progress in Natural Science 18 (2008) 137–142
thought to be a driving force in the succession of certain
environments, especially in extremely degraded ones. In
recent years, the phenomenon of nurse plant has been
investigated in degraded habitats, including Mediterranean
mountain, alpine habitat, arid desert, semi-arid shrub-land,
northern dry forest, savanna, ecotone between farmland
and pasture, swamp, tropical sub-humid forest, marshes,
and so on [2,4–9].
The selection of nurse plants determines the success of
the ecological restoration project. Some nurse plant and
target species pairs have been confirmed in the study of
the world’s main biomes in the past few years. In the
extremely degraded environment, the best nurse plants
are the native species that offer microhabitat for target
plant establishment or recruitment. Although some exotic
species (e.g. Robinia pseudoacacia in southern England)
are successfully used as nurse plant, the biological invasion
of those species should also be prevented. Unpalatable
species can be used in heavily grazed sites, because these
nurse plants can provide refuges for small animals and tar-
get species [2,10,11]. It has been found that acervate plants
evidently facilitate target plant seedling survival in rainless
years. Legumes species are potential nurse plants which can
improve the survival and growth of target species in desert
and Mediterranean semi-arid habitat for their amelioration
in soil nitrogen and overshadow function. However, the
effect is undesirable when both nurse and target plants
are legumes [12]. In desert, shrubs usually act as nurse
plants for other seedlings, especially cacti. In forest, seed-
ling establishment may be enhanced in the vicinity of adult
plants that improve some extreme ecological factors [7].
This kind of positive effect by adult plants on their sur-
rounding seedlings is called Nurse Plant Syndrome. The
selection of nurse plants should avoid those species that
release allelopathic compound. It is reported by Sanchez-
Velasquez et al. [10] that different shaded levels formed
by the nurse plant in the tropical sub-humid forest are
significantly related to seedling establishment of target
species.
Field survey is the foundation of nurse plant research.
Generally, the species richness under nurse plant is higher
than that in the open sites. Therefore, the nursing
relationship between plants can be approximately esti-
mated by interspecific association. Furthermore, the influ-
ence of nurse plant on seed germination of target species
is examined by sowing seeds under nurse plant [13].
Seedling inseminations are mostly introduced in the
confirmation of nurse plant and nursing effect between
plants. In these experiments, the differences of seedlings
of target species under the nurse plant and on the open
(or between two crowns) are usually compared by analyz-
ing survival rate and growth rate between them, combin-
ing observation of microhabitat. However, it should be
indicated that the differences of soil physiochemical prop-
erties and microhabitat between under nurse plant and in
the open are not obvious in some cases of facilitation
[14,15].
2.2. Target species
The effect between plants is dependent on characteristics
of each species, which means the selection of target species
(regenerated ones) would also influence the restoration
effect. Furthermore, the balance of the interaction is
decided by the ecological requirement of target species
and capability of dealing with incompatible habitat [16].
The positive effects of nurse plant on the shaded-tolerant
pine and shrubs in late succession period are more than
those on pioneer species and shaded-intolerant species
[12]. The survival rate of Ambrosia dumosa in the open of
arid environment is higher than that under shrubs because
of its better adaptation in the open habitat, wherein, the
interaction between A. dumosa and the nurse plant is com-
petition, so that this species is not suitable as a target spe-
cies. If the tolerance of target species is poor in abiotic
habitat or the environment is extremely serious (such as
dry year), nurse plant cannot increase the seedling estab-
lishment [17].
The age and size of target species should also be consid-
ered for the balance of facilitation and competition accord-
ing to different life periods. The nurse plant has a stronger
positive effect when the target species is young, whereas,
competitive interaction is dominant when there are older
or bigger target plants. When the age and size of the nurse
plant is similar to that of the target species, the negative
effect of tussock plants will be enhanced [18].
2.3. Positive and negative nursing effect
Only when the intraspecific competition exceeds inter-
specific competition, can plant species coexist in a commu-
nity. Most interactions among species are represented
through some intermediary, for example, light, nutrition,
pollinator, herbivore and microbe. Competition actualizes
by competing resources directly, but facilitation is realized
by intermediary (such as soil) among species interaction
[1,19,20].
Higher recruitment success near the nurse plant cannot
eliminate the negative effect on target species, but it is
sure that positive effects exceed negative ones, which
result in the higher survival rate of target species under
the nurse plant than that in the open [21,22]. When arti-
ficial methods such as shading or watering are used, the
survival rate of target species may be lower than that
under the nurse plants. For example, Neobuxbaumia tet-
etzo, a cactus in Mexico, is nursed by Mimosa luisana,a
leguminous shrub, but the former species restricted the
growth of the nurse plant and consequentially substituted
it. Further research indicated that the survival rate under
the nurse plant was higher than that on the artificial mea-
sures such as shading. In addition, it is shown by the
experiment on Savanna in south Texas that nurse plants
grew better by clearing the target species under the nurse
plants, which can be described as the interaction of the
parasite/host [23,24].
138 H. Ren et al. / Progress in Natural Science 18 (2008) 137–142
Plants, when growing closely, compete directly for lim-
ited resources (such as light, water, nutrition and space)
if negative effect predominates. However, if positive effect
predominates, the neighboring plants will show this inter-
action by increasing survival, growth and fitness. Both
effects would take place simultaneously and change accord-
ing to time and places, which are balanced by expression of
the positive and negative ones. Some factors (such as phys-
iological and developmental characteristics) may influence
the balance [18], wherein the abiotic factors are mostly
important for increasing the importance of positive effect
in stressful habitats [4].
3. Reasons and mechanism of nursing effect
The nursing effect may not be attributed to single factor,
but to the ultimate performance of some compound fac-
tors, including the crown architecture effect (influencing
extinction coefficient, photosynthetic availability radiation,
and temperature buffering), shading increment, buffering
extreme temperature in microhabitat, increasing water,
nutrition availability (litter of nurse plants), protection
against herbivores, impact epiphyte and azotobacter in
soil, and so on. However, among the above environmental
factors, key factors should be explored in finding out the
reasons of nursing effect [2,25].
Nurse plants facilitate target species by shading from
crown architecture. Dewpoint temperature in winter under
nurse plant Cercidium microphyllum was higher than that in
the open of Sonoran Desert. Shading can protect plants
under the nurse plant from strong radiation. Kulheim
et al. [26] reported that light influences plant physiological
process directly and indirectly, and interspecific differences
are found in response to illumination in forest plants.
Strong irradiation may destroy reaction centers of photo-
systems and produce oxidative damages. Shade-tolerant
species under abundant sunlight will suffer from photoinhi-
bition. Shading can avoid higher temperature, maintain
higher soil humidity and lower transpiration of target spe-
cies, moreover, it increases rhizosperic nutritious availabil-
ity and circulation. All the processes above will improve
physical and chemical property of soil and increase survival
rate of target species [2,27,28].
Establishment of target species is affected by rainfall
redistribution of nurse plant canopy. Shrubs constrain
available understory water by rainfall redistribution at a
lower intensity of rainfall, whereas, when there is a heavy
rainfall, its redistribution by shrub crown arrives at under-
story through stem flow, which will influence the develop-
ment of target species [29]. The distance between target
species and nurse plant is another important factor and
the stressful condition is ameliorated gradually from the
center to the edge of canopy [30]. Castro et al. [29] planted
two pine species (Pinus sylvestris and Pinus nigra) in the
open, under the crown of sage (Salvia lavandulifolia) and
beneath the crown of thorny shrubs (north and south direc-
tions), thus finding out that the survival rate was much
higher under the north aspect of thorny shrubs. Nurse
plants influence mainly target species on germination and
seedling stage, wherein, positive effect may be showed evi-
dently on seedling stage. It is believed that, nurse plant of
predominant species in one successional stage will facilitate
plants in the next successional stage by allelopathy.
Changes of physiological balance between shading and
drought were discussed by graph model [2]. In addition,
some factors such as competition, consumption of
resources by the nurse plant and superposition of root
space between the nurse plant and target species should
also be considered. Competition or disturbance of non-tar-
get species under the crown of the nurse plant (i.e. herba-
ceous plants) will play positive roles [1–4].
4. Ecological factors that influence positive effect
Even if positive effect takes place between nurse plant
and target species, ambient condition (such as rainfall, soil
humidity, grazing intensity and microhabitat) influences
the radiation, soil, temperature and moisture under the
crown of nurse plant, thereby changing the nursing effect.
Positive effect of nurse plant increased with stressful abiotic
conditions which was obviously stronger in higher moun-
tains and on earlier restoration stage of degraded ecosys-
tem [4].
In the overexploited area of Mediterranean Basin, 11
woody species were planted under 16 pioneer shrubs, which
could aid in the establishment of woody species on later
successional stage. The successful rate was improved in dif-
ferent habitats by using meta-analysis to analyze survival
and growth among those species [31].
In a relatively nice habitat, spatial association among
plants may be negative, but not positive. In a fertile habitat
it was not positive by using nurse plant for its exhausting of
soil resources. However, in an unfertile habitat, crops with
small crown and poor growth facilitated the survival of syc-
amore seedlings [1,2].
In dry areas, changes in precipitation may alter the
interactions among plants from competition to facilitation
and vice versa. Ibanez and Schupp [32] conducted an exper-
iment in Logan Canyon. They found that when the seed-
lings of curl-leaf mountain mahogany (Cercocarpus
ledifolius) were placed under big sagebrush, facilitation
was apparent in a dry year whereas negative effects were
obvious during a wet year.
5. Case studies of nurse plants in vegetation restoration in
lower subtropical areas of China
The nurse plant should be used in ecological restoration,
mainly because the establishment of target species is greatly
influenced by abiotic habitat and disturbance. Natural
nurse plants were firstly put into ecological restoration in
southeast Spain, where Castro et al. [29] found that native
shrubs did not restrain the growth of two pine species
but decreased their death rate. They comprehensively
H. Ren et al. / Progress in Natural Science 18 (2008) 137–142 139
considered some ecological and biological characteristics,
such as rainfall, nurse species and target species, when
applying nurse plants to improve seed germination and
seedling establishment in ecological restoration.
Through extensive field investigation, interspecific asso-
ciation studies and field experiments, possible correspond-
ing nurse and target species pairs were found in lower
subtropics in China (Table 1).
Tussock plant Evolvulus alsinoides L. with 20 cm root
system and only 3 cm high above ground is the unique nurse
plant grown on a bare land of extremely degraded ecosys-
tem at Xiaoliang, Guangdong Province. We found that E.
alsinoides’s target species Phyllanthus cochinchinensis can
grow with 60 cm root length and 42 cm root spread range
with 27 cm height above ground. In severely degraded eco-
system, there exist two kinds of thresholds during ecosystem
restoration, which are the initial threshold characterized by
extremely harsh physical environmental conditions (includ-
ing high temperature, aridity and poor soil) and the second-
ary threshold controlled mainly by biodiversity level and
landscape context to seed provenance and establishment.
In this circumstance, nurse plants are grass clustered with
deep root, and so are target species. The formed tussock
community is not only propitious to themselves but also
advantageous in their resistance to poor environmental
conditions. Enlightened by the above field phenomenon,
exotic leguminous species, Acacia auriculaeformis, with fast
growth rate and better resistance to infertility, was intro-
duced as nurse plants at the severely degraded bare land
of Xiaoliang. We planted several A. auriculaeformis individ-
uals clusterly, then removed 1–2 individuals of 2-year-old
plants from the fascicular A. auriculaeformis and some
native species were planted under its canopy, including Psy-
chotria rubra,Pithecellobium clypearia,Syzygium hancei,
etc., whose survival rate could reach 80%. The survival rate
is about 0% if those native plants are directly planted in bare
lands. Similar experiment was also successful when carried
out at Nan’ao island [33–35].
It was found that a pioneer grass Neyraudia montana,as
the nurse plant of pioneer shrub Rhodomyrtus tomentosa,
provided better microhabitat at grasslands of Heshan Sta-
tion and Dinghushan Station, Guangdong Province, which
were considered to be mild degraded ecosystem. Pinus mas-
soniana, for its amelioration in light environment and soil
property, was the nurse plant of Schima superba at Heshan
Station, Dinhushan Station and Nan’ao Island. Castanop-
sis chinensis can facilitate Schima superba and Cryptocarya
concinna at Dinghushan Station, probably because of the
effects on shading, moist increment and enhancing avail-
able nutrient in soil [33].
Exotic species Sonneratia apetala has nursing effect on
native mangrove plants Rhizophora stylosa and Kandelia
candel at the coastal mudflat in the tideland area of Zhanji-
ang [36]. We had found that the survival rate of planted
native mangrove species was very low at the severely
degraded mudflat, however, the survival rate of S. apetala
reached 95%. S. apetala grew fast and became a closed
artifical forest within four years which could efficiently pre-
vent the swashing of tidal wave, and increase soil nutrient
therefore facilitating the invasion of some native mangrove
species. The number of species and intensity of native spe-
cies came to a peak in the artificial forests after six years of
growing.
From these nurse plants and target species, the pattern
[36–40] is found as follows. (1) The phenomenon of nurse
plants takes place mostly on the early stages of restoration
in degraded ecosystem or succession in plant community.
(2) The phenomenon of nursing effect on the earlier stage
of restoration or succession is mostly carried out as shrubs
nursed by grasses and trees nursed by shrubs. (3) Nursing
phenomenon usually happens among the native species in
corresponding pairs. (4) Exotic leguminous species, Acacia
auriculaeformis and Acacia mangium, are considered as
good nurse plants for ameliorating N condition in soil
and providing shade for target species including shrubs
and trees. (5) Nurse plants have better characteristics than
Table 1
Possible nurse and target species pairs at south subtropical areas in China
Places Nurse plants Target species
Bare land at Xiaoliang Evolvulus
alsinoides
Phyllanthus
cochinchinensis
Artificial forest at Xiaoliang Acacia
auriculaeformis
Psychotria
rubra
Acacia
auriculaeformis
Pithecellobium
clypearia
Acacia
auriculaeformis
Syzygium
hancei
Hillyland at Heshan Neyraudia
montana
Rhodomyrtus
tomentosa
Rhodomyrtus
tomentosa
Pinus
massoniana
Artificial forest at Heshan Acacia
auriculaeformis
Psychotria
rubra
Acacia
mangium
Michelia
macclurel
Hillyland at Dinhushan Neyraudia
montana
Rhodomyrtus
tomentosa
Coniferous and broad-leaved mixed
forest at Dinghushan
Pinus
massoniana
Schima superba
Castanopsis
chinensis
Schima superba
Broad-leaved forest Castanopsis
chinensis
Cryptocarya
concinna
Artificial forest at Nan’ao Island Pinus
massoniana
Schima superba
Acacia
auriculaeformis
Psychotria
rubra
Acacia
auriculaeformis
Pithecellobium
clypearia
Acacia
auriculaeformis
Schima superba
Artificial mangrove in National
Natural Reserve of Zhanjiang
Sonneratia
apetala
Rhizophora
stylosa
Sonneratia
apetala
Kandelia candel
140 H. Ren et al. / Progress in Natural Science 18 (2008) 137–142
those of target species, including being light-dependent,
fast-growing, infertility resistant and drought tolerant. (6)
The individuals of target species are generally smaller than
those of nurse plants in the early stage. (7) Seedlings can
successfully establish around the adult plants in forests
for the amelioration of some extreme ecological factors.
(8) Nurse plants are considered not only to play a key role
in recovering the properties and functions of the primary
ecosystem, but also to drive succession in poor environ-
ments on the early stage of restoration.
6. Perspective in the study and application of nurse plants
Recently, most researches are focused on seedling sur-
vival of the target species, but less on the research of seed
germination, seedling growth and fitness. Most researches
rest on describing the phenomenon of the nurse effect, less
on the structural and functional mechanisms of positive
effects towards ecophysiological and morphological aspect.
With the purpose of ecological restoration, most researches
concern about the influence of nurse plants on target spe-
cies, but less on the feedbacks of target plants and without
long-term observation in their interactions. Most species
studied are native ones due to easy manipulation and pre-
diction, lacking studies in exotic species. Nurse plants are
mostly tussock shrubs, but not herbaceous or woody spe-
cies, and fewer studies combine nurse plant with target spe-
cies representing different successional stages. Nurse plants
were less investigated in degraded ecosystem, especially in
China, therefore, further tests are needed to find out the
potentials of nurse plants in reforestation.
Currently, the main forest recovery methods include
closing hillsides to facilitate afforestation (natural succes-
sion), artificial reforestation (rebuilding artificial pure for-
ests or mixed forests directly), rebuilding forest
construction (planting native species after picked logging)
and Miyawaki’s method (growing seedlings of native spe-
cies directly). All of these methods have both strong or
weak points. Some reforestation technologies, such as
nutritive cup, water retaining agent, nodules, and shading,
were developed to match the above methods [38–42].
The nurse plant technique is different from the above
reforestation methods. Due to the functions of nurse plant
in ameliorating microhabitat (such as shading and water
increment, extreme temperature buffering in microhabitat,
and so on) suitable target species were grown under the
crown of nurse plants. Even more, positive effects among
plants make target species establish successfully and short-
ened restoration course. The successful utilization of nurse
plants may become a novel reforestation method which will
explore excellent native species, accelerate natural recovery
and enrich species diversity.
Acknowledgements
This work was supported by National Natural Science
Foundation of China (Grant Nos. 30200035, 30670370),
the Chinese Academy of Sciences and the Guangdong &
Guangzhou Sci-Tech Planning Project (07118249,
2005B60301001, 2007J1-C0471). We are grateful to Dr.
Huang Changzhi in CDFG/OSPR/Scientific Division of
Sacramento in USA and Dr. Lu Hongfang in EPA of
USA for the assistance in English writing of this
manuscript.
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... Natural post-fire vegetation recovery is influenced by several major factors such as the presence of perennial plants (Ren et al. 2008;Niknam et al. 2018), spatial scale considered (Gomez-Aparicio 2009), and time scales since the last fire occurrence (He et al. 2019). A wide range of studies have recognized the positive effects of perennial plants, acting as nurse plants, on vegetation structure and soil seed bank in severe ecosystems such as alpine environments and global drylands (Bashirzadeh et al. 2022a;Erfanzadeh et al. 2022;Pashirzad et al. 2019a;Pashirzad et al. 2019b;Soliveres et al. 2015;He et al. 2012;Gomez-Gonz ´ alez ´ et al. 2011) and degraded ones (Gomez-Aparicio 2009; Padilla and Pugnaire 2006;Bashirzadeh et al. 2022b). ...
... A wide range of studies have recognized the positive effects of perennial plants, acting as nurse plants, on vegetation structure and soil seed bank in severe ecosystems such as alpine environments and global drylands (Bashirzadeh et al. 2022a;Erfanzadeh et al. 2022;Pashirzad et al. 2019a;Pashirzad et al. 2019b;Soliveres et al. 2015;He et al. 2012;Gomez-Gonz ´ alez ´ et al. 2011) and degraded ones (Gomez-Aparicio 2009; Padilla and Pugnaire 2006;Bashirzadeh et al. 2022b). The findings of such studies have provided valuable insights into natural vegetation recovery (Bond et al. 2005;Calitz et al. 2015;Bashirzadeh et al. 2022b), and have contributed to the development of restoration practices (Padilla and Pugnaire 2006;Ren et al. 2008). These findings and theories have primarily defined the impacts of nurse plants on the recruitment and survival of less tolerant plant species by creating suitable microenvironments under their canopies. ...
... These findings could provide strong support for the use of plant-based techniques in the restoration practices of burned ecosystems. Implementing such procedures would be considered cost-effective and environmentally friendly, aligning with recent conceptual models that hypothesize plant facilitation as an exploitable interaction in active restoration (Navarro-Cano et al. 2018;Cuevas et al. 2013;Ren et al. 2008). In this regard, nurse plants were identified as a key factor in managing the conservation of vegetation and preventing the loss of plant biodiversity, particularly in the short time since the last fire. ...
Article
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Abstract Backgrounds Plant-plant interactions are among the most important factors affecting the natural recovery of vegetation. While the impacts of nurse plants on species composition and biodiversity are well documented, the effects of different nurse’s growth forms on all biodiversity components including taxonomic, functional, and phylogenetic diversity have been less studied and compared, especially for their effects on different times after fire disturbance. This research was focused on comparing the efects of a perennial grass (Elymus hispidens), a perennial herb (Phlomis can�cellata), and a high shrub species (Lonicera nummulariifolia) on species composition and the biodiversity components, and how these impacts change across five sites with short-term (1 and 4 years sites), long-term (10 and 20 years sites) times since last fire and a control site where no fire was known in recorded history in semi-arid shrublands of Fereizi Chenaran located in Northeast of Iran. The changes of species composition and taxonomic, functional, and phylogenetic diversity were calculated with respect to the presence/absence of nurse’s growth forms, fire history, and their interactions. Results Nurse shrubs affected species composition and all biodiversity components, whereas all indices were reduced when considering Elymus grass as nurse plant. On the other hand, the herb Phlomis enhanced species composition and taxonomic diversity, while it had a negative effect on functional and phylogenetic diversity. Such specific effects of nurse types were mostly observed under long timescales (i.e., 10- and 20-year sites). Interestingly, the relative importance of nurse types and time since the last fire largely explained the variation of species composition and biodiversity components, with larger effects of nurse types on all biodiversity components. However, we found a significant contribution of fire explaining variation of species composition and phylogenetic diversity. Conclusions These results indicated nurse plants can affect the post-fire recovery of vegetation by providing specific mechanisms controlling beneficiary relatedness depending on their growth forms and time scales since the last fire. Therefore, these findings suggest perennial plants in the form of nurse species as a useful factor to develop techniques of active restoration in burned ecosystems
... This effect is well documented in the literature, and referred to as the nurse plant theory (Brooker et al., 2008;Callaway, 1995). Nurse plants provide a variety of benefits to target plant species (Ren et al., 2008) primarily by providing conditions more favourable than the surrounding environments, such as reduced light intensity (Valiente-Banuet & Ezcurra, 1991), lower temperatures in summer (Godínez-Álvarez et al., 2003), higher temperatures in winter (Duker et al., 2015), higher soil humidity and nutrient content (Muro-Pérez et al., 2012), and herbivore avoidance (Padilla & Pugnaire, 2006). The benefits provided to the transplanted seedlings in the shade of grasses could be related to any of the above. ...
... Indeed, facilitation effects have been identified between nurse plants and various succulents in the Asphodelaceae (Dortort, 2024;Duncan et al., 2005;Molteno et al., 2017;Titus et al., 2012;van Blerk, 2013). The benefits of shading from nurse plants have also been noted in several other conservation translocation studies Menges et al., 2016;Ren et al., 2008). ...
... In addition, some evidence suggests that, functional traits such as life form, plant height, specific leaf area and leaf carbon and nitrogen content can impact the functioning of terrestrial ecosystems (Badano et al. 2016) and consequently change the fire occurrence (Bowd 2018). Such changes in species composition and functional traits following the fire may or may not result in significant variation in evolutionary diversity, depending on how functional traits are conserved across phylogenies (Ren et al. 2008;He et al. 2019). Plants regeneration becomes the main indictor of management and sustainable development of arid and semiarid shrublands (Bowman et al. 2016). ...
... Plants regeneration becomes the main indictor of management and sustainable development of arid and semiarid shrublands (Bowman et al. 2016). However, restoration is highly dependent on disturbances (Ren et al. 2008;Pausas and Ribeiro 2013;Vallego et al. 2012) and the previous abundance of plant species (Bahalkeh et al. 2021). Continuing climate change, droughts and extreme weather, coupled with associated changes in wildfire activity (Abatzoglou and Williams 2016) are resulting in landscape ecosystem changes and shifts in biodiversity composition (Stevens-Rumann et al. 2017). ...
Article
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Algeria, like several Mediterranean countries, was exposed to devastating wildfires. These fires are a key disturbance affecting plant biodiversity patterns and evolution, causing significant threats to lives, property and economic activity in the country. The Kabylia region, in particular, through the last few years, has undergone tragic consequences due to wildfires. In context, we assessed the recovery of floristic biodiversity and the soil vegetation relationship, in order to evaluate the fire impact on this ecosystem. A qualitative inventory of plant species and a physico-chemical analyzes were carried out in the stations of Sidi Ali Bounab; considered as a reference site (A), since it was preserved from fires and the devastated Ikhelidjen site (B), with a big fire, in the Kabylia region (Northern Algeria). the survey was carriedout, during the spring (April- June) of the year 2022 and 2023, after 2021 big fires. The flora inventory, in Sidi Ali Bounab not burned site (A), revealed the presence of 55 species are belonging to 4 classes (Magnoliopsida, Equisetopsida, Liliopsida and Polypodiopsida) and to 50 genera, 31 botanical families, 25 orders, with the Asteraeae family dominance. At the same time, the flora survey in Ikhlidjen burned area revealed a total richness of 49 species belonging to 3 classes (Magnoliopsida, Liliopsida and Equisetopsida) spread over 43 genera, 20 families, and 19 orders. The flora regeneration was observed within the Asteraceae and Fabaceae families in a soil which presents a low alkaline and high organic matter content. The analyzes of the chemical properties, from both sites (A&B), showed that the quality of the soil favorized the installation and the diversification of the flora based on their loamy-sandy texture rich in organic, especially in the burned station and their pH as well as their electrical conductivity, which was confirmed by the ecological indices analyzes.
... This is the case of the nurseprotégé association, where this facilitation is a common strategy in arid zones in which plants mitigate the extreme temperature, solar radiation, desiccation, and herbivory of other plants (Muro-Pérez et al., 2009;Withgott, 2000). The effects of nurse plants are considered especially beneficial to the early stages of plant growth (Flores & Jurado, 2003;Ren et al., 2008;Withgott, 2000), but it is not known how these associations (Grüter & Ratnieks, 2011). Additionally, closed areas could interfere with the flight of approaching insects. ...
... The nurse plant associations have been studied mainly for the protection of seeds and seedlings (Flores & Jurado, 2003;Muro-Pérez et al., 2009;Ren et al., 2008;Withgott, 2000) but less commonly on how it influences flower visitors and pollinators. In this study, the frequencies of flower visitors per hour were negatively affected by six nurse plants and/or object combinations, but positively by the Acacia sp. ...
Article
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Biotic and environmental conditions could affect the plant-flower visitor dynamics and, consequently, the fruit set in angiosperms. The aims of this study were: 1) to test the effect of microenvironment on activity of flower visitors in a population of Astrophytum myriostigma and 2) to describe the plant-flower visitor network’s structure. Data were recorded during two synchronous flowerings. The effect of microenvironment on flower visitors’ activity was tested through generalized linear models, and the interaction network structure was described. Frequency and duration of visits were mainly affected by atmospheric pressure and dew point. There were fewer flower visitors on plants located close to nurses and rocks. The interaction network topology tends to have a nested structure. Due to pollinators’ decline, these findings help understand the drivers limiting the flower visitors’ activity. The interactions between flower visitors and plants could be affected by atmospheric pressure alterations triggered by climate change.
... Additionally, diversifying the composition of transplanted foundation species may take advantage of interspecific facilitation that increases the revegetation rate (Derksen-Hooijberg et al., 2018;King et al., 2023). This technique has been demonstrated in a variety of ecosystems where the survivorship and growth of target foundational plants is enhanced by planting them alongside nurse plants that provide shade and shelter from harsh environmental conditions (Blanco-García et al., 2011;Miyasaka et al., 2014;Ren et al., 2008). When used in isolation, these restoration strategies can enhance the lateral expansion and habitatprovisioning services of ecosystem-building species. ...
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The increasing frequency and severity of disturbances to coastal dune ecosystems requires developing and implementing restoration strategies that rapidly accelerate re‐establishment of vegetation, enhance dune accretion, and ultimately preserve dune ecosystem services. To assess how to rapidly re‐establish vegetation to counter ecosystem losses, we conducted a manipulative field experiment on a created foredune crest in Northeast Florida, USA to determine what combinations of planting density, outplant species composition, and nutrient addition maximize dune revegetation rate. Above‐ground biomass in densely planted plots with added nutrients was 4.7–7.3 times that of plots planted at conventional restoration densities after only 3 months. Critically, thickly vegetated, high‐density plots with nutrient addition accreted 1–5 cm more sediment after 3 months and 7.5–22 cm more sediment after 15 months, demonstrating that this planting method can rapidly kickstart dune‐building processes. Additionally, above‐ and below‐ground biomass in densely planted, fertilized plots containing bitter panicum (Panicum amarum) were consistently higher and accreted more sand than similar plots planted with sea oats (Uniola paniculata), suggesting that planting schemes involving this early successional species may be most effective for rapid dune‐building. Synthesis and applications. Because coupling nutrient addition with dense planting can trigger self‐sustaining, reinforcing plant growth and dune‐building feedbacks within only months, this planting approach may help to enhance the long‐term success of dune restoration projects.
... Most of our active restoration sites were dominated by broadleaved Eucalyptus species with low canopy cover, which facilitates native species recolonization (Lemenih et al. 2004). This is due to the potential for these plantation trees to modify the microclimate under their canopy (Ren et al. 2008), creating resource heterogeneity (Redon et al. 2014), and facilitating the colonization of generalist and opportunistic plant species (Onaindia et al. 2013). Higher regeneration diversity in actively restored sites may also be related to high seed bank diversity (Senbeta et al. 2002), as most sites lie on previously degraded species-rich forests that were converted into grazing lands before plantation establishment. ...
Article
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Global deforestation and forest degradation threaten the sustainability of natural and human systems. Forest landscape restoration , through active approaches such as plantations, woodlots, boundary planting, and agroforestry, and passive approaches like exclosures, presents an opportunity to mitigate adverse effects, enhance ecosystem service recovery, and associated benefits for livelihoods. Here, using different spatial scales, we compare the contribution of both approaches to the recovery of plant diversity in southern Ethiopia. Using forest inventory data (891 plots) from multi-aged stands, we estimated and compared alpha (α), beta (β), and gamma (γ) diversity in regeneration and tree layers between the approaches. We observed increasing α-diversity in the order grazing lands-active-passive-forest sites. β-Diversity revealed similarity between passively restored sites and natural forests. γ-Diversity was higher in active restoration for the regeneration layer, but passive restoration had higher γ-diversity in the tree layer. For both approaches, γ-diversity was consistently highest in intermediate-aged stands (10-20 years). Results highlight the potential of active restoration strategies to facilitate vegetation recovery in human-dominated landscapes, especially when management allows natural regeneration, while stand age variation may be associated with disturbance intensities for both approaches. Our results support a paradigm shift toward implementation of a mixture of these approaches in the landscapes to meet increasing human demands while restoring important ecosystem services like biodiversity. We recommend enhancing species diversity on restored sites to improve performance and ecosystem service recovery. On actively restored sites, we recommend protecting regenerated species; on passively restored sites, enrichment planting, increased protection, and sustainable utilization.
... Nurse plants might protect desired regeneration (Urretavizcaya and Defossé 2013). Cluster plantings, where nurse seedlings are planted around a desired species (Saha et al. 2016), utilize facilitation effects whereby species interact to the benefit of at least one with harm to none (Filazzola and Lortie 2014;Ren et al. 2008;Soliveres et al. 2012). Clusters facilitate establishment by altering microclimates and providing physical protection. ...
... Nurse plants might protect desired regeneration (Urretavizcaya and Defossé 2013). Cluster plantings, where nurse seedlings are planted around a desired species (Saha et al. 2016), utilize facilitation effects whereby species interact to the benefit of at least one with harm to none (Filazzola and Lortie 2014;Ren et al. 2008;Soliveres et al. 2012). Clusters facilitate establishment by altering microclimates and providing physical protection. ...
Chapter
This book takes a multidisciplinary perspective to analyze and discuss the various opportunities and challenges of restoring tree and forest cover to address regional and global environmental challenges that threaten human well-being and compromise sustainable development. It examines forest restoration commitments, policies and programs, and their planning and implementation at different scales and contexts, and how forest restoration helps to mitigate environmental, societal, and cultural challenges. The chapters explore the concept of forest restoration, how it can restitute forest ecosystem services, contribute to biodiversity conservation, and generate benefits and synergies, while recognizing the considerable costs, trade-offs, and variable feasibility of its implementation. The chapters review historic and contemporary forest restoration practice and governance, variations in approaches and implementation across the globe, and relevant technological advances. Using the insights from the ten topic-focused chapters, the book reflects on the possibility of sustainable and just approaches to meet the challenges that lie ahead to achieve ambitious international forest restoration targets and commitments.
... Plant-plant interactions were a major driving force in plant community succession or vegetation restoration [54]. Positive (promotion) and negative (competition) effects existed and occured simultaneously between plants in the community, and the environmental conditions determined which effect was more important [26]. ...
Article
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Vegetation construction is a key process for restoring and rehabilitating degraded ecosystems. However, the spatial pattern and process of native plants colonized by different vegetation restoration methods in semi-arid sandy land are poorly understood. In this study, two artificial vegetation restoration patterns (P1: row belt restoration pattern of Salix matsudana with low coverage; P2: a living sand barrier pattern of Caryopteris mongolica with low coverage) were selected to analyze the spatial distribution pattern and interspecific association of the colonizing native shrubs. The effects of the two restoration models on the spatial patterns of the main native semi-shrubs of the colonies (i.e., Artemisia ordosica and Corethrodendron lignosum var. leave) were studied using single variable and bivariate transformation point pattern analysis based on Ripley’s L function. Our results showed that two restoration patterns significantly facilitated the establishment of A. ordosica and C. lignosum var. leave, with their coverage reaching 17.04% and 22.62%, respectively. In P1, the spatial distribution pattern of colonial shrubs tended to be a random distribution, and there was no spatial correlation between the species. In P2, the colonial shrub aggregation distribution was more dominant, and with the increase in scale, the aggregation distribution changed to a random distribution, whereas the interspecific association was negatively correlated. The differences in the spatial distribution patterns of colonized native semi-shrubs in these two restoration patterns could be related to the life form of planted plants, configuration methods, biological characteristics of colonized plants, and intra- and interspecific relationships of plants. Our results demonstrated that the nurse effect of artificially planted vegetation in the early stage of sand ecological restoration effectively facilitated the near-natural succession of communities. These findings have important implications for ecological restoration of degraded sandy land in the semi-arid region of northern China.
Article
Restoration researchers and practitioners alike advocate for novel restoration approaches, informed by ecological theories and principles, to enhance the likelihood of meeting restoration goals. Forested wetland restoration has historically focused on creating abiotic conditions that support the tolerance thresholds of desired species, but the stress gradient hypothesis provides guidance for potential new strategies that use biotic interactions to ameliorate stressful abiotic conditions. In this study, we tested whether multi‐species planting approaches can be used to enhance the survival and growth of a target restoration tree species, Bald cypress, along multiple abiotic gradients. We conducted a fully factorial controlled greenhouse experiment which manipulated above‐ and belowground interactions between two species (Bald cypress and Soft rush), as well as light availability and depth of inundation. Our findings showed that co‐planting Bald cypress seedlings with Soft rush did not increase tree biomass production or growth metrics (e.g. stem height and leaf area) under any exposed stress combination. Importantly, we found that full‐sun irradiance negatively impacted functional traits associated with the tree seedlings' health and ability to photosynthesize. Our findings are important for consideration by practitioners as light is rarely the focus of wetland ecosystem restoration and degraded forested wetlands or restoration sites often have open canopies.
Article
Seven man-made broad-leaved mixed forests with an area of 6.4 ha were established in 1964-1979 on an extremely degraded land in south China. The number of species and individuals and Shannon-Wiener Index (H) of the plantations increased gradually after afforestation. The H value of some of the plantations were close to that of the secondary forest. A total of 47 native species invaded and some planted species disappeared in the plantations in 30 years. However, no tree invaded the contrasting barren land since reforestation. This suggested that the process of natural restoration of the tropical seasonal rain forest is a potentially slow process in the extremely degraded ecosystem, but plant diversity of tropical seasonal rain forest can be restored after afforestation in natural condition. Natural succession cannot be considered as a useful management option in extremely degraded region.
Article
In a mixed desert shrub community we removed and added shrub canopies to examine above- and belowground influences of 3 species of shrubs on islands of soil fertility and the survival of transplanted Ambrosia dumosa seedlings. Soils sampled under shrubs in the wet season had higher pH, water content, organic matter, and both total and mineralizable nitrogen than soils in adjacent open areas, confirming a widely established pattern in arid lands. However, we also found species differences in soil parameters. Soils under Coleogyne ramosissima had highest pH, soils under A. dumosa had highest water content and nitrogen mineralization rates, and soils under Larrea tridentata had lowest water content. Soils sampled under shrubs in the dry season, 7 months after experimental shrub removal maintained higher organic matter and total and mineralizable nitrogen content than adjacent open soils, but pH and water were altered by shrub manipulations. Species differences persisted only in soil water levels (A. dumosa soils were driest). Over a 1-year period, transplanted A. dumosa seedlings had highest survivorship in shrub removal and open treatments and died most rapidly under control shrubs of all 3 species, suggesting that shrubs had a strong negative effect on seedling survival, even in the presence of higher organic matter, nutrients, and (initially) higher water content of fertile islands. Our results suggest that nurse plants and islands of soil fertility have the potential to facilitate growth of other species by nutrient additions, but that the net effect of nurse plants can be negative due to shading and/or root competition.
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In contrast to documented increases in woody plant dominance of savannas and grasslands of North America, oak (Quercus L.) savannas that form lower tree lines in the southwestern United States and northwestern Mexico have been stable over the last several centuries. We sought to identify potential biotic and abiotic constraints on seedling recruitment of Quercus emoryi within the context of potential shifts in lower tree line. We used held surveys to describe seedling distribution at and below lower tree line, and to determine the potential. for acorn dispersal from lower tree line into adjacent grassland. Field and greenhouse experiments were used to test explanatory hypotheses generated by descriptive surveys. Q. emoryi seedlings were located almost exclusively beneath mature, conspecific tree canopies within the woodland and savanna and were absent from adjacent semidesert grassland in 1993 and 1995. Seed bank surveys indicated that acorns were concentrated beneath tree canopies and were dispersed into adjacent grassland in low numbers. Although soil N, C, and P were about two times greater beneath trees than in adjacent grassland, experimental nutrient amendments to subcanopy and grassland soils indicated that soil nutrients did not limit Q. emoryi growth. Reciprocal transfers of subcanopy and grassland soil to subcanopy and grassland microsites indicated that microsite was more important than soil source for seedling growth. Overstory shade was important at all stages of seedling development investigated: the provision of artificial or natural shade increased rates of seedling emergence and subsequent survival as much as 19-fold and increased recruitment rates between 30- and 60-fold. We conclude that rates of Q. emoryi recruitment within grasslands below tree line are relatively low and are constrained by low rates of seed dispersal coupled with a low probability of seedling emergence. In contrast, large numbers of acorns are dispersed directly beneath Q. emoryi trees, where they have a higher probability of emergence than in adjacent grassland. Survival rates of emerged seedlings were low, regardless of landscape position. Thus, observed patterns of seedling distribution on the landscape resulted from interactions between seed dispersal and habitat-specific response of seedlings to environmental variation. Results of this and complementary research suggest that the lower tree line in southern Arizona is stabilized by self-enhancing feedback mechanisms of overstory shade, seed dispersal, and seedling establishment, coupled with strong abiotic constraints beyond the current ecotone. These processes stabilize the woodland-grassland ecotone both spatially and temporally, consistent with Wilson and Agnew's one-sided positive feedback switch. Although this switch would not produce an indefinitely stable vegetation mosaic, upslope or downslope shifts in lower tree line are apparently resistant to decadal or even century-scale climatic perturbation. The observed shift in tree line in the last millennium was less likely the result of slow, spatial progression of autogenic safe sites than the result of episodic and infrequent allogenic processes that simulated or negated the importance of conspecific, biogenic safe sites.
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The establishment phase of Neobuxbaumia tetetzo, a giant columnar cactus, occurs mostly beneath the canopies of trees and shrubs which act as nurse plants. This pattern cannot be attributed to preferential seed dispersion, as Neobuxbaumia fruits open while still on the plant, dropping c1000 seeds fruit-1 randomly around the parent plant. Mimosa luisana is the most abundant shrub in the community. Seed germination was lowest in open spaces. In all treatments, exclusion from predators significantly increased seedling survival. Only shaded treatments had live individuals at the end of the experiment, 2 yr later. Results suggest that the nurse-plant effect between N. tetetzo and M. luisana is chiefly the result of differential survival in shaded microsites with less direct solar radiation, and consequently with lower daytime temperatures and lower evaporative demand. Field samplings were conducted in two Mexican deserts located outside the tropical belt: the Vizcaino Desert in Baja California and the Gran Desierto de Altar in Sonora. In these deserts direct solar radiation has a southern azimuth all year round. Five of six succulent species analysed showed a significant pattern of greater establishment on the shaded north sides of nurse plants. -from Authors
Article
After a millenarian history of overexploitation, most forests in the Medi- terranean Basin have disappeared, leaving many degraded landscapes that have been re- colonized by early successional shrub-dominated communities. Common reforestation tech- niques treat these shrubs as competitors against newly planted tree seedlings; thus shrubs are cleared before tree plantation. However, empirical studies and theory governing plant- plant interactions suggest that, in stress-prone Mediterranean environments, shrubs can have a net positive effect on recruitment of other species. Between 1997 and 2001, we carried out experimental reforestations in the Sierra Nevada Protected Area (southeast Spain) with the aim of comparing the survival and growth of seedlings planted in open areas (the current reforestation technique) with seedlings planted under the canopy of preexisting shrub species. Over 18 000 seedlings of 11 woody species were planted under 16 different nurse shrubs throughout a broad geographical area. We sought to explore variation in the sign and magnitude of interactions along spatial gradients defined by altitude and aspect. In the present work, we report the results of a meta-analysis conducted with seedling survival and growth data for the first summer following planting, the most critical period for reforestation success in Mediterranean areas. The facilitative effect was consistent in all environmental situations explored (grand mean effect size d 1 5 0.89 for survival and 0.27 for growth). However, there were differences in the magnitude of the interaction, depending on the seedling species planted as well as the nurse shrub species involved. Additionally, nurse shrubs had a stronger facilitative effect on seedling survival and growth at low altitudes and sunny, drier slopes than at high altitudes or shady, wetter slopes. Facilitation in the dry years proved higher than in the one wet year. Our results show that pioneer shrubs facilitate the establishment of woody, late-successional Mediterranean spe- cies and thus can positively affect reforestation success in many different ecological settings.