������Ƶ

Here we go again — another era of the dreaded ohia dieback. We are all panicked by the pronouncements of the experts, and our agency folks are still stirred up. (“Rushing To Save Kauai’s Ohia Trees From A Deadly, Fast-Spreading Disease.”)

Agency pathology experts from the mainland have again come over to pronounce the dire consequences of new disease organisms and insect vectors related to what they have seen happen to unrelated cold-climate tree species on the North American continent. Unfortunately, they seem to know little about oceanic tropical island ecosystems.

As before, they have spawned heightened concern in local agencies that are properly protective of our native forests.�� However, there is a lot of drastic-measure hype about suspected rapid ohia death trees (cut ’em, tarp ’em, save the seeds!). They discuss funneling limited conservation funding into coordinated agency response behaviors and drastic measures for the after-apocalypse.

The bottom line is there is a lot not known about the deaths of ohia trees, and not yet enough rational research into what really is going on. There is no shortage of opinions — including mine — as to what is going on, but clearly more study is needed before anybody knows for sure what different mechanisms are responsible for aggregated and individual deaths of the trees, what that means for action now, and most importantly — what happens naturally afterwards.��The primary focus is still on death, not the natural recovery.

This is not the first time we have seen such dire pathologist pronouncements — a century ago on young lava flows of east Maui near Keanae, and again��35-40 years ago on Hawaii Island.��In the latter period, there were a series of assessments and calls for drastic measures because all our ohia forests were doomed.�� There then��began two lines of research — one that focused on a disease organism or two that were definitely blamed for the demise.

Death From Natural Causes

The second line of research was much broader, and it concluded that the ohia deaths were due to natural causes related to nutrient deficiencies, and that the dead trees were succeeded by suites of young ohia trees right beneath them in a natural cycle of canopy growth, death and re-growth. This cycle has been most evident on young lava flow habitats that tended to be short on nutrients, but occurs elsewhere as well. In the end, after years of work, both lines of research concluded that the phenomenon was primarily due to natural causes, and in most circumstances the new cohorts of ohia grew up underneath the snags of the old. A lot of money was spent and a lot of wild-ass management actions were proposed.

“My vote is on ohia being the survivor it has always been.”

Perhaps contemporary researchers would do well to read the older study reports or the 2013 book “Ohia Lehua Rainforest” (lead author D. Mueller-Dombois).��Recent follow-up assessments of the older die-back forests indicated that most of the affected forest areas sampled recovered quite nicely. The exceptions were where alien species moved in or had already done so to prevent the ohia recovery.

For me, my vote is on ohia being the survivor it has always been.��There appears to be a couple of new diseases to hasten and expand the ohia trees’ mortality, but the bottom line is that these native species have the genetic resilience and broad dispersal capability to re-colonize��their own habitats unless invasive alien trees take over first and shade them out.

The numerous kinds of ohia trees are likely to mix up their genes while they create huge numbers of wind-blown seeds, all without our help. In places I have looked that have suffered collective ohia canopy loss or reduction,I have seen seedlings and saplings coming back into play, both then and now. I refuse to be pushed to panic.

A far more productive approach would be to stop the flow of live and cut ornamental plants into Hawaii, as they tend to arrive with associated diseases, insects, slugs, etc.�� We used to grow our own ornamentals — we can do it again. Impose realistic and effective bio-security for Hawaii ASAP.