I think as a part of an ecosystem each invasive species both flora or fauna restore biomass. just remember the productivity that is the rate at which biomass (including carbon) is produced per unit area by any class of organisms. There are primary productivity at autotrophic level and secondary productivity at heterotrophic level. So either the invasive species is flora or fauna, it will perform as carbon pool in the ecosystem. As a part of the system, invasive species give services through biogeochemical cycle or play important role in food web network or composing structure in the system. For plant especially, it contribute Oxygen, canopy, shelter, food, or other to the system. so removing plant invasive species will remove carbon sequester species.

I don't think invasive or native species are going to make difference on carbon sink. Guess these can perform equally.

Yes, they would and, because of their faster growth rates, dominance, etc., they could even do better BUT one has to consider the other environmental impacts that invasive species have (eg. loss of biodiversity, local community composition and function, trophic cascade, etc.

So if invasive species leads to loss of biodiversity but at thesame time performs equally as native species in climate change mitigation, why do we need to restore native species?

it is will known that invasion doesn't occur unless the biotic and abiotic factors are unfavorable for the native species. as we are talking about carbon sink we have to distinguish first between the different plant types as it differ from the permanent and temporal vegetative cover, as well as differentiate between herbaceous, shrubs or tree. in general and in my opinion as Benjamin and Sulistiyowati says it depends to certain extent as one of the factors that affect climate change in term of carbon traps this action affected by way or another by the type and extent of the biogeochemical reaction that associate the presence of this plant. plant biomass is the measuring tools to determine and measure trapped carbon, and so it is very important to say that I think yes, invasive plants can act positively on carbon sink as the native types are absent.

We need to restore native plant species bacause many animals, particularly insects, birds and small mammals rely on them for food and, to a lesser extent, shelter. These animals often cannot process invasive species. It is well dcoumented that loss of native plant species leads to loss of effective ecological functioning and there is a cascading or domino effect on the ecosystem.

Fatima native species are critical for ecosystem functioning and invassive species will reduce the biodiversity. Carbon sequestration is not their primary function.

Example Prosopis juliflora: this invasive species in Africa --- see paper attached --- plays an increasing role in the C-cycle. As long as it is growing where nothing else is planted, the plant is an asset with a divers potential and use. If the Prosopis-thickets would be gradually managed as bundle-trees, phantastic forests could evolve. The plant has its friends and enemies, the balancing and conclusions need some wise orientation and precise knowledge. Thus: Invasive plants can definately serve as an important carbon-sink.