Sustainability of New Zealand high‐country pastures under contrasting development inputs. 7. Environmental gradients, plant species selection, and diversity

Plant functional traits are fundamental to the understanding of plant adaptations and distributions. Recently, scientists proposed a trait-based species selection theory to support the selection of suitable plant species to restore the degraded ecosystems, to prevent the invasive exotic species and to manage the sustainable ecosystems. Based on this theory, in a previous study, we developed a species screening model and successfully applied it to a project where plant species were selected for restoring a tropical coral island. However, during this process we learned that a software platform is necessary to automate the selection process because it can flexible to assist users. Here, we developed a generalized software platform called the “Restoration Plant Species Selection (RPSS) Platform.” This flexible software is designed to assist users in selecting plant species for particular purposes (e.g., restore the degraded ecosystems and others). It is written in R language and integrated with external R packages, including the packages that computing similarity indexes, providing graphic outputs, and offering web functions. The software has a web-based graphical user interface that allows users to execute required functions via checkboxes and buttons. The platform has cross-platform functionality, which means that it can run on all common operating systems (e.g., Windows, Linux, macOS, and others). We also illustrate a successful case study in which the software platform was used to select suitable plant species for restoration purpose. The objective of this paper is to introduce the newly developed software platform RPSS and to provide useful guidances on using it for various applications. At this step, we also realized that the software platform should be constantly updated (e.g., add new features) in the future. Based on the existing successful application and the possible updates, we believe that our RPSS software platform will have broader applications in the future.

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STRATEGI PEMILIHAN JENIS TANAMAN UNTUK MENDUKUNG REHABILITASI PESISIR BERDASARKAN KARAKTERISTIK FISIK MAKRO DI MUARA SUNGAI PROGO (Strategy of Plant-Species Selection for Coastal Rehabilition Based on Macro-physical Characteristics in Progo Estuary)

Jurnal Manusia dan Lingkungan ◽

10.22146/jml.18809 ◽

2017 ◽

Vol 23 (3) ◽

pp. 349

Author(s):

Budiadi Budiadi ◽

Handojo Hadi Nurjanto ◽

Suryo Hardiwinoto ◽

Enggal Primananda

Keyword(s):

Plant Species ◽

Physical Characteristics ◽

Species Selection ◽

Selection For

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Functional Ecology of Iceplant Taxa and Their Role in Eco-restoration of New Zealand Sand Dunes

10.26686/wgtn.17000419 ◽

2021 ◽

Author(s):

◽

Guyo Duba Gufu

Keyword(s):

New Zealand ◽

Plant Species ◽

Plant Communities ◽

Growth Rates ◽

Sand Dunes ◽

Intergeneric Hybrid ◽

Leaf Production ◽

Natural Plant ◽

Carpobrotus Edulis

<p>Biological invasion by non-native plant species has often been cited as a cause of native biodiversity loss. While the outcome of species invasions depends on interactions between exotic and resident native species, most studies of biological invasions have focused solely on the direct negative impacts of non-indigenous species on native biota. Although investigations of the role of competition in shaping natural plant communities were dominant in the previous generations and are still popular, more recent experimental research has uncovered the striking influence of facilitation on community dynamics. This thesis aims to investigate competitive and facilitative influence of the invasive South African iceplant (Carpobrotus edulis) on Spinifex sericeus, a native foredune grass species, with particular reference to implications of these interactions for dune restoration in New Zealand. It further explores the growth rates, substrate preferences and mating systems of the exotic and native iceplant taxa found in New Zealand. I begin by briefly outlining the influence of competition and facilitation on natural plant communities with reference to the role of facilitation in eco-restoration. I also give a few examples where exotic species have been found to facilitate native ones. Secondly, a neighbour removal experiment was conducted on coastal sand dunes with the main aim of studying the effects of Carpobrotus edulis on establishment of Spinifex sericeus at the foredune region. Finally, I compared the growth rates of the most widely distributed iceplant taxa in New Zealand in different substrates and the breeding systems of the exotic Carpobrotus. Examples abound in literature of exotic plant species facilitating native ones especially in forestry. In the neighbour removal study, Carpobrotus edulis protected Spinifex seedlings against storm erosion, sandblasting and salt sprays while at the same time suppressing its leaf production. Suppression of Spinifex leaf production was more pronounced at top of the dune where stress elements is presumably more benign. There was no evidence of allelopathic suppression of Spinifex by C. edulis. Only Carpobrotus chilensis displayed some level of substrate preference by putting on relatively lower biomass in gravel. The exotic Carpobrotus spp. put on greater dry matter content than the native Disphyma australe and the Carpobrotus-x-Disphyma hybrid. The hybrid displayed a faster vegetative growth rate whereas D. australe allocated relatively more biomass to the roots than the shoot. Both Carpobrotus spp. are self compatible and highly capable of intrageneric and intergeneric hybridisation. Mass removal of the existing exotic iceplant stands from foredunes along high energy coasts is not advisable as they serve as useful stabilisers. The intergeneric hybrid is sexually sterile with sparsely spread stolons that could allow co-occurrence with other species and therefore is more suitable for foredune stabilisation. However, more research needs to be conducted on the ecology of the intergeneric hybrid.</p>

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Interactive effects of climate change and plant invasion on alpine biodiversity and ecosystem dynamics

10.26686/wgtn.17138738.v1 ◽

2021 ◽

Author(s):

◽

Justyna Giejsztowt

Keyword(s):

Climate Change ◽

New Zealand ◽

Plant Species ◽

Climate Warming ◽

Plant Invasion ◽

Invasive Plant ◽

Ecosystem Dynamics ◽

Interactive Effects ◽

Native Plant ◽

Competition For Pollination

<p>Drivers of global change have direct impacts on the structure of communities and functioning of ecosystems, and interactions between drivers may buffer or exacerbate these direct effects. Interactions among drivers can lead to complex non-linear outcomes for ecosystems, communities and species, but are infrequently quantified. Through a combination of experimental, observational and modelling approaches, I address critical gaps in our understanding of the interactive effects of climate change and plant invasion, using Tongariro National Park (TNP; New Zealand) as a model. TNP is an alpine ecosystem of cultural significance which hosts a unique flora with high rates of endemism. TNP is invaded by the perennial shrub Calluna vulgaris (L.) Hull. My objectives were to: 1) determine whether species-specific phenological shifts have the potential to alter the reproductive capacity of native plants in landscapes affected by invasion; 2) determine whether the effect of invasion intensity on the Species Area Relationship (SAR) of native alpine plant species is influenced by environmental stress; 3) develop a novel modelling framework that would account for density-dependent competitive interactions between native species and C. vulgaris and implement it to determine the combined risk of climate change and plant invasion on the distribution of native plant species; and 4) explore the possible mechanisms leading to a discrepancy in C. vulgaris invasion success on the North and South Islands of New Zealand. I show that species-specific phenological responses to climate warming increase the flowering overlap between a native and an invasive plant. I then show that competition for pollination with the invader decreases the sexual reproduction of the native in some landscapes. I therefore illustrate a previously undescribed interaction between climate warming and plant invasion where the effects of competition for pollination with an invader on the sexual reproduction of the native may be exacerbated by climate warming. Furthermore, I describe a previously unknown pattern of changing invasive plant impact on SAR along an environmental stress gradient. Namely, I demonstrate that interactions between an invasive plant and local native plant species richness become increasingly facilitative along elevational gradients and that the strength of plant interactions is dependent on invader biomass. I then show that the consequences of changing plant interactions at a local scale for the slope of SAR is dependent on the pervasion of the invader. Next, I demonstrate that the inclusion of invasive species density data in distribution models for a native plant leads to greater reductions in predicted native plant distribution and density under future climate change scenarios relative to models based on climate suitability alone. Finally, I find no evidence for large-scale climatic, edaphic, and vegetative limitations to invasion by C. vulgaris on either the North and South Islands of New Zealand. Instead, my results suggest that discrepancies in invasive spread between islands may be driven by human activity: C. vulgaris is associated with the same levels of human disturbance on both islands despite differences in the presence of these conditions between then islands. Altogether, these results show that interactive effects between drivers on biodiversity and ecosystem dynamics are frequently not additive or linear. Therefore, accurate predictions of global change impacts on community structure and ecosystems function require experiments and models which include of interactions among drivers such as climate change and species invasion. These results are pertinent to effective conservation management as most landscapes are concurrently affected by multiple drivers of global environmental change.</p>

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