[ERA Webinar]: Invasive Plants Part II: Why Do Invasions Happen in the First Place?

In the second panel discussion in the series, our panelists step back and look at the bigger picture, and explore potential root causes and conditions that may be enabling “invasions” by species in the first place.

Are there prior causes that we should understand before jumping to solve the invasives problem? Is it as simple as labelling a species as “aggressive” or “problematic”? Could it be that the threat of invasives is actually being driven by other human induced threats to ecosystems?

This discussion is more of a collective inquiry into the issue of invasive plants in the larger context of what is happening in the world today. It’s meant to nurture and create space for inquiry. Viewers are encouraged to approach the discussion with an open mind.

00:00:01 – Suprabha sets the context
00:04:48 – Introducting Dr Rohan Shetti
00:05:23 – Invasives, Invasion and Restoration
00:10:56 – How one species came to dominate a forest in Europe
00:11:39 – When soil changes, what's on top also changes
00:14:30 – How human factors can compound invasion
00:18:11 – Addressing soil conditions as a prerequisite to restoration
00:22:12 – Introducing Dr Mahesh Sankaran
00:22:42 – Forest grassland mosaics
00:28:02 – Woody plant introduction in the Nilgiris grasslands
00:30:09 – Impacts of invasive species on plant species diversity and composition
00:31:26 – There’s much higher nitrogen and nitrate availability in the invaded grasslands
00:33:50 – Woody plant invasions have altered fire regimes
00:35:12 – What allows woody plants to invade grasslands?
00:40:03 – Question: How and why do plant invasions change soil nutrients?
00:42:20 – Question: Not all policies are right
00:45:59 – Question: How leaching affects organisms
00:48:23 – Introducing Aliston Texeira
00:49:03 – Observations from a farm
00:52:17 – The plants could be choosing certain niches to occupy
00:59:02 – Modern environments are inundated with pollution
01:04:16 – We need to widen our lens
01:08:30 – Question: Aliston’s observations on Wedelia (invasive plant)
01:10:53 – Discussion: The role of nutrition in a landscape
01:16:13 – Excessive nutrition is pollution and could be enabling invasions
01:16:56 – A possible scenario if an invasion isn't stopped
01:24:42 – The role of disturbance in plant distribution
Q-A
01:35:33 – How do we control nutrition in natural forests which have been invaded?
01:37:37 – Managing nutrition in farmlands while maintaining biodiversity services
01:42:45 – Should restoration also focus on reducing excessive nutrition/pollution?
01:51:27 – Growth of invasives along roads and linear infrastructure
01:57:15 – A few closing thoughts